CN114270666A - Armature - Google Patents

Abstract

The stator (730) includes a multi-phase stator winding (731) which is cylindrical and has a phase winding composed of a plurality of partial windings (851) for each phase. The partial winding has: a pair of intermediate lead portions (871) provided at a predetermined interval in the circumferential direction; and bridging portions 872, 873 provided on one end side and the other end side in the axial direction and connecting the pair of intermediate lead portions in a ring shape, wherein the lead material 852 is wound in a plurality of layers in the pair of intermediate lead portions and each of the bridging portions, and each of the bridging portions on both sides in the axial direction is bent in the radial direction. The overlapping portions on both sides in the axial direction are bent in opposite directions to each other in the radial direction. The lead length L1 on the outside diameter side of the bend and the lead length L2 on the inside diameter side of the bend are L1 > L2 in the range from the tip position of the bridging portion to a predetermined position in the axial direction of the intermediate lead portion.

Description

Armature

Citation of related applications

The present application is based on the patent application No. 2019-152257, which is applied on 8/22/2019, and the description thereof is incorporated herein by reference.

Technical Field

The disclosure in this specification relates to an armature of a rotating electrical machine.

Background

Conventionally, there is known a rotating electrical machine including: a field element including a magnet portion having a plurality of magnetic poles whose polarities alternate in a circumferential direction; and an armature having a multiphase armature winding. The armature winding has a phase winding for each phase. In addition, the following structures are known: in the armature winding, the phase winding of each phase is configured to include a plurality of partial windings, and the partial windings are arranged in a circumferential direction.

Patent document 1 discloses, as an example of a partial winding structure, a die winding coil (japanese patent: coil コイル) in which a wire material or a thin wire as an electric wire member is wound in an annular shape and a coil side end portion is bent in a radial direction. In the partial winding (die-wound coil), a portion corresponding to the end of the coil side is a crossover portion extending in the circumferential direction, and a plurality of the partial windings are arranged in the circumferential direction in a state where the crossover portions intersect with each other. In this case, interference of the partial windings with each other is avoided due to the overlapping portion being bent in the radial direction.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-230484

Disclosure of Invention

In the case of manufacturing the above-described partial coil, it is conceivable to bend the axial end portions (lap portions) of the annular air-core coil in the radial direction after the annular air-core coil is manufactured, in view of manufacturing convenience. However, when the axial end portion of the air-core coil is bent in the radial direction, the bending radius (curvature) differs between the portion that becomes the inner diameter side and the portion that becomes the outer diameter side in the bent portion, and the bending radius is larger (the curvature becomes smaller) on the outer diameter side than on the inner diameter side. In this case, since the length required for bending is longer on the bending outer diameter side than on the bending inner diameter side, in the leading end portion of the lap portion of the partial winding (the connecting portion extending in the circumferential direction in the lap portion), a shift in the leading end position occurs on the bending inner diameter side and the bending outer diameter side. Therefore, it is considered that the coil cross section in the leading end portion of the lap portion of the partial winding is not rectangular but skewed into a parallelogram, and the radial projecting length (projecting length) of the lap portion becomes longer. Further, if the radial projecting length of the lap portion becomes too long, there is a possibility that a problem such as interference with other members arranged on the inner side in the radial direction of the armature winding is likely to occur.

The present disclosure has been made in view of the above circumstances, and an object thereof is to provide an armature that can be easily manufactured and can suppress an increase in size due to bending in a radial direction.

The various aspects disclosed in the present specification achieve the respective objects by adopting mutually different technical means. The objects, features and effects disclosed in the present specification can be more clearly understood by referring to the following detailed description and accompanying drawings.

The mode 1 is an armature of a type,

the armature includes a multi-phase armature winding having a cylindrical shape and having a phase winding composed of a plurality of partial windings for each phase,

the partial winding includes: a pair of intermediate conductor portions provided at a predetermined interval in a circumferential direction; and a bridging portion provided at one end side and the other end side in the axial direction and connecting the pair of intermediate lead portions annularly, wherein a lead material is wound in a plurality of layers in the pair of intermediate lead portions and each of the bridging portions, and each of the bridging portions at both sides in the axial direction is bent in the radial direction,

the overlapping portions on both sides in the axial direction are bent in opposite directions to each other in the radial direction,

The lead length L1 on the outside diameter side of the bend and the lead length L2 on the inside diameter side of the bend are L1 > L2 in the range from the front end position of the bridging portion to a predetermined position in the axial direction of the intermediate lead portion.

In the structure in which the crossover portion in the partial winding of the armature winding is bent in the radial direction, the bending radii on the inner diameter side and the outer diameter side in the bent portion are different, and therefore, the radial protrusion length is longer on the inner diameter side where the bending radius is smaller than on the outer diameter side. In this case, the radial projecting length (projecting length) of the overlapping portion becomes long.

In contrast, in the above configuration, the crossover sections on both sides in the axial direction are bent in mutually opposite directions in the radial direction, and L1 > L2 are obtained when the lead length on the outer diameter side of the bend is L1 and the lead length on the inner diameter side of the bend is L2 in the range from the tip position of the crossover section to the predetermined position in the axial direction of the intermediate lead section. That is, in the lap portion of the partial winding, the bending radius on the bending outer diameter side is larger and the length required for bending is longer than that on the bending inner diameter side, but by bending the lap portion in the opposite directions to each other in the radial direction on both sides in the axial direction and making L1 > L2, it is possible to make the lap portion bend desirably while making the difference in the wire length at the inside and outside of the bending cancel each other out. In this case, when the lap portion is formed by bending, the coil cross section at the tip portion (the connection portion extending in the circumferential direction) of the lap portion can be suppressed from being obliquely distorted, and the protruding length (protruding length) in the radial direction of the lap portion can be reduced. As a result, the manufacturing of the armature winding is facilitated, and the increase in size due to the radial bending can be suppressed.

The lap portion is a portion corresponding to the coil side end portion of the armature winding. The predetermined position in the axial direction of the intermediate conductor portion is preferably a boundary position between a coil side portion and a coil side end portion of the armature winding, for example. Alternatively, the predetermined position in the axial direction of the intermediate conductor portion may be an intermediate position within a range of the coil side portion of the armature winding.

In the aspect 2, in addition to the aspect 1, a distal end surface of the lap portion which becomes a bent distal end is formed in a direction parallel to the axial direction.

As described above, in the configuration in which the tip end surface that becomes the bent tip end in the lap portion is formed in the direction parallel to the axial direction, the radial protrusion length (i.e., the amount of radial protrusion from the intermediate lead portion) on the bent outer diameter side and the bent inner diameter side can be made equal in the lap portion of the partial winding. This can still reduce the projection length with the radial bending.

In addition, the bending angle of the radial bend in the overlapping portion is preferably at a right angle with respect to the axial direction. However, the bending angle may be a non-right angle (e.g., an obtuse angle) with respect to the axial direction. In any case, the tip end surface of the lap portion, which is the bent tip end, may be formed in a direction parallel to the axial direction.

Embodiment 3 is the case where, in addition to embodiment 1 or embodiment 2, the lap joint portion includes: a pair of bent portions extending from the pair of intermediate lead portions and bent in a radial direction; and a connecting portion extending in a circumferential direction between the pair of bent portions, the pair of bent portions being bent in a direction orthogonal to the axial direction, wherein a cross section of a lead assembly made of a plurality of layers of the lead material is rectangular in the connecting portion.

In the above configuration, the pair of bent portions are bent in a direction orthogonal to the axial direction at the overlapping portion of the partial windings, and the cross section of the lead wire assembly is rectangular at the connection portion. In this case, the axial length of the partial winding can be reduced, and the projection length along with the radial bending can be reduced.

Mode 4 is the case where, in addition to any one of modes 1 to 3, the lap joint portion on one axial side and the lap joint portion on the other axial side have the same radius of curvature in the radial direction.

In the above configuration, since the radii of curvature of the lap portions on the one side and the other side in the axial direction are the same, the deformation (distortion) of the cross-sectional shape in the bending direction in each of the lap portions can be appropriately cancelled out. This enables optimization of the cross-sectional shape of the lap portion on both sides in the axial direction.

A mode 5 is the mode according to any one of the modes 1 to 4, wherein one of the pair of intermediate lead portions of the partial winding of the other phase is disposed between the pair of intermediate lead portions of the partial winding, and the respective lap portions of the partial windings of different phases are disposed in a state of being overlapped in an axial direction, whereby the intermediate lead portions of the respective phases are arranged in a predetermined order in a circumferential direction.

According to the above configuration, when the plurality of partial windings are arranged in the circumferential direction, the partial windings can be ideally arranged while suppressing interference with each other.

A mode 6 is an armature according to the mode 5, wherein the armature includes a base member having a cylindrical back yoke, and the armature winding is integrated with the base member by assembling the partial winding on a radially outer side or a radially inner side of the back yoke, the partial winding has a first partial winding and a second partial winding assembled to the base member while being shifted in at least an axial direction by a thickness of a wire assembly made of a plurality of layers of the wire material, the lap portions of the first partial winding and the second partial winding are bent inward in the radial direction on one of both axial sides of the base member, respectively, the lap portions of the first partial winding are disposed on the axially inner side, the lap portions of the second partial winding are disposed on the axially outer side, and the lap portions are disposed on the other axial side of both axial sides of the base member, the lap portions of the first partial winding and the second partial winding are bent radially outward, respectively, and the lap portions of the first partial winding are disposed axially outward and the lap portions of the second partial winding are disposed axially inward.

According to the above configuration, the first partial winding and the second partial winding are assembled to the base member while being shifted at least by the thickness of the wire assembly in the axial direction, and the overlapping portion of the partial winding is bent inward in the radial direction on one axial side of the base member and is bent outward in the radial direction on the other axial side. The first and second partial windings are disposed so that the overlapping portions of the first and second partial windings in the axial direction are opposite to each other in the axial direction. In this case, even if the partial windings having a common structure are used, the partial windings can be appropriately arranged.

A mode 7 is the armature winding according to any one of modes 1 to 6, wherein the armature winding includes a plurality of coil modules, the plurality of coil modules include the partial winding and a back yoke side insulating wall provided on the back yoke side of the partial winding, the plurality of coil modules are arranged in a circumferential direction on a radially inner side or a radially outer side of the base member, the base member is provided with a first engaging portion, the back yoke side insulating wall of the coil module is provided with a second engaging portion, and the coil modules are fixed to the base member in a state of being engaged in the circumferential direction by the first engaging portion and the second engaging portion.

In the above configuration, the coil module is fixed to the base member in a state of being circumferentially engaged by the first engaging portion provided in the base member including the back yoke and the second engaging portion provided in the back yoke-side insulating wall of the coil module. This can suppress positional displacement of each coil module (partial winding) with respect to the circumferential direction of the base member, and improve the positional accuracy in the circumferential direction. In this case, even an armature having a structure not including pole teeth extending in the radial direction from the back yoke, that is, an armature having a non-notched structure, can be assembled with the armature winding desirably.

Mode 8 is the case where, in addition to mode 7, the base member has an end portion ring fixed to at least one of end surfaces of both ends of the back yoke in the axial direction, and the first engaging portion is provided in the end portion ring.

In the above configuration, the back yoke contributing to the performance of the rotating electrical machine may not be provided with the irregularities for circumferential engagement, and the coil module may be appropriately fixed to the base member without changing the performance and characteristics of the back yoke. For example, as compared with a case where the back yoke is provided with projections and recesses for engagement, it is possible to suppress the cogging torque from being deteriorated.

In addition, the end rings are preferably constructed of a non-magnetic material. Thus, even if the end portion ring is provided with the concave-convex portion for circumferential engagement, the magnetic influence on the armature can be suppressed. That is, the cogging torque can be prevented from deteriorating.

Drawings

The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. The drawings are as follows.

Fig. 1 is a longitudinal sectional perspective view of a rotating electric machine.

Fig. 2 is a longitudinal sectional view of the rotating electric machine.

Fig. 3 is a sectional view taken along line III-III of fig. 2.

Fig. 4 is an enlarged cross-sectional view of a portion of fig. 3.

Fig. 5 is an exploded view of the rotary electric machine.

Fig. 6 is an exploded view of the inverter unit.

Fig. 7 is a torque line graph showing a relationship between the ampere-turns of the stator winding and the torque density.

Fig. 8 is a cross-sectional view of the rotor and stator.

Fig. 9 is an enlarged view of a part of fig. 8.

Fig. 10 is a cross-sectional view of the stator.

Fig. 11 is a longitudinal sectional view of the stator.

Fig. 12 is a perspective view of the stator winding.

Fig. 13 is a perspective view showing the structure of the lead.

Fig. 14 is a schematic diagram showing the structure of the wire rod.

Fig. 15 is a diagram showing the form of each conductive line of the n-th layer.

Fig. 16 is a side view showing each conductive line of the nth layer and the (n + 1) th layer.

Fig. 17 is a diagram showing a relationship between an electrical angle and a magnetic flux density of the magnet according to the embodiment.

Fig. 18 is a diagram showing a relationship between an electrical angle and a magnetic flux density of the magnet of the comparative example.

Fig. 19 is a circuit diagram of a control system of the rotating electric machine.

Fig. 20 is a functional block diagram showing a current feedback control process of the control device.

Fig. 21 is a functional block diagram showing a torque feedback control process of the control device.

Fig. 22 is a cross-sectional view of a rotor and a stator of the second embodiment.

Fig. 23 is an enlarged view of a part of fig. 22.

Fig. 24 is a diagram specifically showing the flow of the magnetic flux of the magnet unit.

Fig. 25 is a sectional view of a stator according to modification 1.

Fig. 26 is a sectional view of a stator according to modification 1.

Fig. 27 is a sectional view of a stator according to modification 2.

Fig. 28 is a sectional view of a stator according to modification 3.

Fig. 29 is a sectional view of a stator according to modification 4.

Fig. 30 is a cross-sectional view of a rotor and a stator according to modification 7.

Fig. 31 is a functional block diagram showing a part of the processing of the operation signal generation unit in modification 8.

Fig. 32 is a flowchart showing a procedure of the carrier frequency changing process.

Fig. 33 is a diagram showing a connection mode of each lead constituting a lead group in modification 9.

Fig. 34 is a diagram showing a structure in which four pairs of lead wires are stacked in modification 9.

Fig. 35 is a cross-sectional view of the rotor and the stator of the inner rotor type according to modification 10.

Fig. 36 is an enlarged view showing a part of fig. 35.

Fig. 37 is a longitudinal sectional view of the inner rotor type rotating electric machine.

Fig. 38 is a longitudinal sectional view showing a schematic structure of the inner rotor type rotating electric machine.

Fig. 39 is a diagram showing a structure of a rotary electric machine having an inner rotor structure according to modification 11.

Fig. 40 is a diagram showing a structure of a rotary electric machine having an inner rotor structure according to modification 11.

Fig. 41 is a diagram showing a structure of a rotary armature type rotating electric machine according to modification 12.

Fig. 42 is a cross-sectional view showing the structure of a lead wire according to modification 14.

Fig. 43 is a diagram showing a relationship among reluctance torque, magnet torque, and DM.

Fig. 44 is a view showing a pole tooth.

Fig. 45 is a perspective view showing a wheel and its peripheral structure of an in-wheel motor structure.

Fig. 46 is a longitudinal sectional view of the wheel and its peripheral structure.

Fig. 47 is an exploded perspective view of the wheel.

Fig. 48 is a side view of the rotating electric machine as viewed from the protruding side of the rotating shaft.

Fig. 49 is a cross-sectional view taken along line 49-49 of fig. 48.

Fig. 50 is a cross-sectional view taken along line 50-50 of fig. 49.

Fig. 51 is an exploded sectional view of the rotary electric machine.

Fig. 52 is a partial sectional view of the rotor.

Fig. 53 is a perspective view of the stator winding and the stator core.

Fig. 54 is a front view showing a stator winding which is spread out in a planar manner.

Fig. 55 is a diagram showing skew of the conductive wire.

Fig. 56 is an exploded sectional view of the inverter unit.

Fig. 57 is an exploded sectional view of the inverter unit.

Fig. 58 is a diagram showing the arrangement state of the electric modules in the inverter case.

Fig. 59 is a circuit diagram showing an electrical configuration of the power converter.

Fig. 60 is a diagram showing an example of a cooling structure of the switch module.

Fig. 61 is a diagram showing an example of a cooling structure of the switch module.

Fig. 62 is a diagram showing an example of a cooling structure of the switch module.

Fig. 63 is a diagram showing an example of a cooling structure of the switch module.

Fig. 64 is a diagram showing an example of a cooling structure of the switch module.

Fig. 65 is a diagram showing an arrangement order of the electric modules with respect to the cooling water passage.

Fig. 66 is a cross-sectional view taken along line 66-66 of fig. 49.

Fig. 67 is a cross-sectional view taken along line 67-67 of fig. 49.

Fig. 68 is a perspective view showing a bus bar module as a single body.

Fig. 69 is a view showing an electrical connection state between each electrical module and the bus bar module.

Fig. 70 is a view showing an electrical connection state between each electrical module and the bus bar module.

Fig. 71 is a diagram showing an electrical connection state between each electrical module and the bus bar module.

Fig. 72 is a configuration diagram for explaining modification 1 of the in-wheel motor.

Fig. 73 is a configuration diagram for explaining modification 2 of the in-wheel motor.

Fig. 74 is a configuration diagram for explaining modification 3 of the in-wheel motor.

Fig. 75 is a configuration diagram for explaining modification 4 of the in-wheel motor.

Fig. 76 is a perspective view showing the entire rotary electric machine according to modification 15.

Fig. 77 is a longitudinal sectional view of the rotating electric machine.

Fig. 78 is an exploded sectional view of the rotary electric machine.

Fig. 79 is a sectional view of the rotor.

Fig. 80 is a partial sectional view showing a sectional structure of the magnet unit.

Fig. 81 is a partial sectional view showing an enlarged part of the magnet unit.

Fig. 82 is a perspective view showing a structure of a stator.

Fig. 83 is a perspective view showing the stator winding and the stator core in an exploded manner.

Fig. 84 is a perspective view showing only the structure corresponding to the U-phase winding in the phase windings of the respective phases.

Fig. 85 is a longitudinal sectional view of the stator.

Fig. 86 is a circuit diagram showing a connection state of a part of windings among the windings of each phase of three phases.

Fig. 87 is a diagram showing a structure of a coil module.

Fig. 88 is a diagram showing a structure of a coil module.

Fig. 89 is a diagram showing a structure of a coil module.

Fig. 90 is a diagram showing a structure of a coil module.

Fig. 91 is a sectional view showing a longitudinal section of a stator.

Fig. 92 is a sectional view showing a cross section of a stator.

Fig. 93 is a sectional view showing the stator core and the end rings and the coil modules separately from each other.

Fig. 94 is a longitudinal sectional view of the inner unit.

Fig. 95 is a longitudinal sectional view of the internal unit.

Fig. 96 is a perspective view of a bus bar module.

Fig. 97 is a sectional view showing a part of a longitudinal section of the bus bar module.

Fig. 98 is a schematic diagram showing the connection position of the connection terminal with respect to each bus bar.

Fig. 99 is a diagram showing a winding sequence of the conductive wire in the partial winding.

Fig. 100 is a diagram showing a structure of a coil module.

Fig. 101 is a vertical sectional view showing the structure of a coil module according to modification 16.

Fig. 102 is a diagram showing a structure of a partial winding.

Fig. 103 is a diagram showing a structure of a coil module.

Fig. 104 is a sectional view showing a longitudinal section of the stator.

Fig. 105 is a partial plan view of the stator as viewed from the axial side.

Fig. 106 is a diagram showing a partial winding of the related art.

Fig. 107 is a diagram showing a structure of a partial winding.

Fig. 108 is a diagram for explaining a method of manufacturing a partial winding.

Fig. 109 is a diagram for explaining a method of manufacturing a partial winding.

Fig. 110 is a diagram for explaining another example of a partial winding.

Fig. 111 is a diagram showing a structure of a partial winding according to modification 17.

Fig. 112 is a vertical cross-sectional view showing a state in which a plurality of partial windings are assembled to a stator core.

Fig. 113 is an enlarged view of the structure of the lap portion of the partial winding.

Fig. 114 is a diagram for explaining a method of manufacturing a partial winding.

Fig. 115 is a diagram for explaining a method of manufacturing a partial winding.

Fig. 116 is a diagram for explaining another example of the partial winding.

Fig. 117 is a plan view showing a state where a plurality of partial windings are assembled to a stator core.

Detailed Description

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In the embodiments, the same reference signs are given to functionally and/or structurally corresponding parts and/or related parts, or reference signs differing by more than one hundred bits are given. For corresponding parts and/or associated parts, reference may be made to the description of the other embodiments.

The rotating electric machine in the present embodiment is used as a vehicle power source, for example. However, the rotating electric machine is widely used for industrial use, vehicles, home appliances, OA equipment, game machines, and the like. In the following embodiments, the same or equivalent portions are denoted by the same reference numerals in the drawings, and the description thereof will be referred to for the portions having the same reference numerals.

(first embodiment)

The rotating electrical machine 10 of the present embodiment is a synchronous multiphase ac motor, and has an outer rotor structure (external rotor structure). Fig. 1 to 5 show an outline of the rotary electric machine 10. Fig. 1 is a vertical sectional perspective view of a rotary electric machine 10, fig. 2 is a vertical sectional view of the rotary electric machine 10 in a direction along a rotary shaft 11, fig. 3 is a transverse sectional view of the rotary electric machine 10 in a direction perpendicular to the rotary shaft 11 (a sectional view taken along line III-III in fig. 2), fig. 4 is a sectional view showing a part of fig. 3 in an enlarged manner, and fig. 5 is an exploded view of the rotary electric machine 10. In fig. 3, for convenience of illustration, the hatching indicating the cut surface is omitted except for the rotary shaft 11. In the following description, a direction in which the rotary shaft 11 extends is an axial direction, a direction in which the rotary shaft 11 radially extends from the center thereof is a radial direction, and a direction in which the rotary shaft 11 circumferentially extends around the center thereof is a circumferential direction.

The rotary electric machine 10 generally includes a bearing unit 20, a housing 30, a rotor 40, a stator 50, and an inverter unit 60. The rotating electric machine 10 is configured by disposing the above-described members coaxially with the rotating shaft 11 and assembling them in the axial direction in a predetermined order. The rotating electrical machine 10 of the present embodiment has a structure including a rotor 40 as a "field element" and a stator 50 as an "armature", and is specifically a rotating electrical machine of a rotating field excitation type.

The bearing unit 20 includes: two bearings 21, 22 arranged apart from each other in the axial direction; and a holding member 23 for holding the bearings 21 and 22. The bearings 21, 22 are, for example, radial ball bearings, and each have: an outer ring 25, an inner ring 26, and a plurality of balls 27 disposed between the outer ring 25 and the inner ring 26. The holding member 23 is cylindrical, and the bearings 21 and 22 are assembled on the radially inner side of the holding member 23. The rotary shaft 11 and the rotor 40 are rotatably supported radially inside the bearings 21 and 22. The bearings 21 and 22 constitute a set of bearings, and rotatably support the rotary shaft 11.

In each of the bearings 21 and 22, the balls 27 are held by a retainer not shown, and in this state, the pitch between the balls is held. The bearings 21 and 22 have seal members at upper and lower portions in the axial direction of the holder, and are filled with nonconductive grease (e.g., nonconductive urea grease) at the insides thereof. Further, the position of the inner ring 26 is mechanically held by the spacer, and a constant pressure preload that protrudes in the up-down direction is applied from the inside.

The housing 30 has a cylindrical peripheral wall 31. The peripheral wall 31 has first and second ends opposite in the axial direction thereof. The peripheral wall 31 has an end face 32 at a first end and an opening 33 at a second end. The opening 33 is open at the entire second end. A circular hole 34 is formed in the center of the end surface 32, and the bearing unit 20 is fixed by a fixing member such as a screw or a rivet in a state inserted through the hole 34. Further, a hollow cylindrical rotor 40 and a hollow cylindrical stator 50 are housed in the housing 30, that is, in an internal space defined by the peripheral wall 31 and the end face 32. In the present embodiment, the rotating electric machine 10 is an outer rotor type, and a stator 50 is disposed inside a casing 30 in the radial direction of a rotor 40 having a cylindrical shape. The rotor 40 is supported by the rotary shaft 11 in an axially cantilevered manner on the end surface 32 side.

The rotor 40 has: a magnet holder 41 formed in a hollow cylindrical shape; and a ring-shaped magnet unit 42 provided on the radially inner side of the magnet holder 41. The magnet holder 41 has a substantially cup shape and functions as a magnet holding member. The magnet holder 41 has: a cylindrical portion 43 having a cylindrical shape; a fixing portion (connecting portion) 44 which is also cylindrical and has a smaller diameter than the cylindrical portion 43; and an intermediate portion 45 as a portion connecting the cylindrical portion 43 and the fixing portion 44. The magnet unit 42 is attached to the inner circumferential surface of the cylindrical portion 43.

The magnet holder 41 is made of cold-rolled Steel Plate (SPCC), forged steel, Carbon Fiber Reinforced Plastic (CFRP), or the like, which has sufficient mechanical strength.

The rotation shaft 11 is inserted through the through hole 44a of the fixing portion 44. The fixing portion 44 is fixed to the rotating shaft 11 provided in the through hole 44 a. That is, the magnet holder 41 is fixed to the rotary shaft 11 by the fixing portion 44. The fixing portion 44 is preferably fixed to the rotary shaft 11 by spline coupling, key coupling, welding, caulking, or the like using irregularities. Thereby, the rotor 40 and the rotary shaft 11 rotate integrally.

Further, the bearings 21, 22 of the bearing unit 20 are assembled to the radially outer side of the fixing portion 44. As described above, since the bearing unit 20 is fixed to the end surface 32 of the housing 30, the rotary shaft 11 and the rotor 40 are rotatably supported by the housing 30. Thereby, the rotor 40 is rotatable in the housing 30.

The rotor 40 is provided with a fixing portion 44 only at one of two axially opposite end portions thereof, and thereby the rotor 40 is supported in a cantilever manner on the rotary shaft 11. Here, the fixed portion 44 of the rotor 40 is rotatably supported by the bearings 21, 22 of the bearing unit 20 at two different positions in the axial direction. That is, the rotor 40 is rotatably supported by the two bearings 21 and 22 that are separated in the axial direction at one of the two ends of the magnet holder 41 that face each other in the axial direction. Therefore, even in the structure in which the rotor 40 is supported by the rotary shaft 11 in a cantilever manner, stable rotation of the rotor 40 can be achieved. In this case, the rotor 40 is supported by the bearings 21, 22 at a position offset to one side with respect to the axial center position of the rotor 40.

In the bearing unit 20, the size of the gap between the outer ring 25 and the inner ring 26 and the balls 27 is different between the bearing 22 near the center (lower side in the figure) of the rotor 40 and the bearing 21 on the opposite side (upper side in the figure), and for example, the size of the gap is larger in the bearing 22 near the center of the rotor 40 than in the bearing 21 on the opposite side. In this case, even if vibration due to vibration of the rotor 40 or imbalance caused by component tolerance acts on the bearing unit 20 on the side close to the center of the rotor 40, the influence of the vibration or vibration can be absorbed favorably. Specifically, the play size (clearance size) is increased by the preload in the bearing 22 near the center (lower side in the figure) of the rotor 40, and the vibration generated in the cantilever structure can be absorbed by the play portion. The preload may be either a constant position preload or a constant pressure preload. In the case of constant-position preload, the outer rings 25 of the bearings 21 and 22 are both joined to the holding member 23 by press-fitting, bonding, or the like. Further, the bearing 21 and the inner ring 26 of the bearing 22 are both joined to the rotary shaft 11 by press-fitting, bonding, or the like. Here, the preload can be generated by disposing the outer ring 25 of the bearing 21 at a position different from the inner ring 26 of the bearing 21 in the axial direction. The preload can be generated by disposing the outer ring 25 of the bearing 22 at a position different from the inner ring 26 of the bearing 22 in the axial direction.

In the case of using the constant pressure preload, a preload spring, for example, a wave washer 24 or the like is disposed in the region sandwiched between the bearing 22 and the bearing 21 in order to generate the preload from the region sandwiched between the bearing 22 and the bearing 21 toward the outer ring 25 of the bearing 22 in the axial direction. In this case, the bearing 21 and the inner ring 26 of the bearing 22 are also joined to the rotary shaft 11 by press-fitting, bonding, or the like. The outer ring 25 of the bearing 21 or the bearing 22 is disposed on the holding member 23 with a predetermined gap therebetween. With the above configuration, the elastic force of the preload spring acts on the outer ring 25 of the bearing 22 in a direction away from the bearing 21. Then, the force is transmitted to the rotary shaft 11, and a force pressing the inner ring 26 of the bearing 21 in the direction of the bearing 22 acts thereon. Thus, with respect to the bearings 21, 22, the axial positions of the outer ring 25 and the inner ring 26 are both shifted, so that preload can be applied to both bearings as in the above-described constant-position preload.

In addition, when the constant pressure preload is generated, it is not necessary to apply the elastic force to the outer ring 25 of the bearing 22 as shown in fig. 2. For example, the outer ring 25 of the bearing 21 may be provided with an elastic force. Further, the inner ring 26 of either of the bearings 21 and 22 may be disposed on the rotary shaft 11 with a predetermined gap therebetween, and the outer ring 25 of the bearings 21 and 22 may be joined to the holding member 23 by a method such as press-fitting or bonding, thereby applying preload to both bearings.

Furthermore, when a force is applied to move the inner ring 26 of the bearing 21 away from the bearing 22, it is preferable to apply a force to move the inner ring 26 of the bearing 22 away from the bearing 21 as well. Conversely, when a force is applied to bring the inner race 26 of the bearing 21 closer to the bearing 22, it is preferable to apply a force to bring the inner race 26 of the bearing 22 also closer to the bearing 21.

When the rotating electric machine 10 is applied to a vehicle for the purpose of a power source of the vehicle or the like, vibration having a component in the direction of generation of the preload may be applied to the mechanism that generates the preload, and the direction of gravity of the object to which the preload is applied may vary. Therefore, in the case where the present rotating electrical machine 10 is applied to a vehicle, it is desirable to employ a constant position pre-pressure.

The intermediate portion 45 has an annular inner shoulder 49a and an annular outer shoulder 49 b. The outer shoulder 49b is located radially outward of the inner shoulder 49a in the intermediate portion 45. The inner shoulder portion 49a and the outer shoulder portion 49b are separated from each other in the axial direction of the intermediate portion 45. Thereby, the cylindrical portion 43 and the fixing portion 44 partially overlap in the radial direction of the intermediate portion 45. That is, the cylindrical portion 43 protrudes axially outward beyond the base end portion (lower-side end portion in the figure) of the fixing portion 44. According to this configuration, as compared with the case where the intermediate portion 45 is formed into a flat plate shape without a step, the rotor 40 can be supported by the rotary shaft 11 at a position near the center of gravity of the rotor 40, and stable operation of the rotor 40 can be achieved.

According to the configuration of the intermediate portion 45, in the rotor 40, a bearing accommodating recess 46 that accommodates a part of the bearing unit 20 is annularly formed at a position radially surrounding the fixed portion 44 and closer to the inside of the intermediate portion 45, and a coil accommodating recess 47 that accommodates a coil side end 54 of a stator winding 51 of the stator 50 described later is formed at a position radially surrounding the bearing accommodating recess 46 and closer to the outside of the intermediate portion 45. The receiving recesses 46 and 47 are arranged adjacent to each other in the radial direction. That is, a part of the bearing unit 20 and the coil side end 54 of the stator winding 51 are arranged to overlap radially inward and outward. This can shorten the axial length of the rotating electric machine 10.

The intermediate portion 45 is provided to protrude radially outward from the rotation shaft 11 side. Further, the intermediate portion 45 is provided with a contact avoiding portion extending in the axial direction, which avoids contact with the coil side end portions 54 of the stator windings 51 of the stator 50. The intermediate portion 45 corresponds to a protruding portion.

The axial dimension of the coil side end 54 can be reduced by bending the coil side end 54 radially inward or outward, and the axial length of the stator 50 can be shortened. The direction of the bending of the coil side end 54 is preferably considered for assembly with the rotor 40. When the stator 50 is assembled to the radially inner side of the rotor 40, the coil side end 54 is preferably bent radially inward on the insertion tip side of the rotor 40. The direction of bending of the coil side end portion on the opposite side of the coil side end portion 54 may be arbitrary, but a shape bent to the outside that is spatially redundant is preferable for manufacturing reasons.

The magnet unit 42 as a magnet portion is configured by a plurality of permanent magnets arranged so that polarities thereof are alternately changed in the circumferential direction on the radially inner side of the cylindrical portion 43. Thus, the magnet unit 42 has a plurality of magnetic poles in the circumferential direction. The magnet unit 42 is described in detail later.

The stator 50 is disposed radially inward of the rotor 40. The stator 50 includes a stator winding 51 formed in a substantially cylindrical (annular) shape by winding and a stator core 52 as a base member disposed radially inward of the stator winding 51, and the stator winding 51 is disposed so as to face the annular magnet unit 42 with a predetermined air gap therebetween. The stator winding 51 is formed of a plurality of phase windings. The phase windings are formed by connecting a plurality of conductor lines arranged in the circumferential direction at predetermined intervals. In the present embodiment, the stator winding 51 is configured as a six-phase winding by using three-phase windings of U-phase, V-phase, and W-phase and three-phase windings of X-phase, Y-phase, and Z-phase, and using two sets of the three-phase windings.

The stator core 52 is formed in an annular shape from a laminated steel plate in which electromagnetic steel plates as soft magnetic materials are laminated, and is assembled to the inside in the radial direction of the stator winding 51. The electromagnetic steel sheet is, for example, a silicon steel sheet in which silicon is added to iron by about several percent (e.g., 3%). The stator winding 51 corresponds to an armature winding, and the stator core 52 corresponds to an armature core.

The stator winding 51 has a coil side portion 53 which is a portion overlapping the stator core 52 in the radial direction and is positioned radially outward of the stator core 52, and coil side end portions 54, 55 which protrude toward one end side and the other end side of the stator core 52 in the axial direction, respectively. The coil side portion 53 is radially opposed to the stator core 52 and the magnet unit 42 of the rotor 40, respectively. In a state where the stator 50 is disposed inside the rotor 40, the coil side end 54 located on the bearing unit 20 side (upper side in the drawing) of the coil side ends 54, 55 on both sides in the axial direction is accommodated in the coil accommodating recess 47 formed by the magnet holder 41 of the rotor 40. The stator 50 is described in detail later.

The inverter unit 60 includes: a unit base 61 fixed to the housing 30 by a fastener such as a bolt; and a plurality of electrical components 62 assembled to the unit base 61. The unit base 61 is made of, for example, Carbon Fiber Reinforced Plastic (CFRP). The unit base 61 includes: an end plate 63 fixed to an edge of the opening 33 of the housing 30; and a housing 64 integrally provided to the end plate 63 and extending in the axial direction. The end plate 63 has a circular opening 65 at a central portion thereof, and forms a housing 64 so as to stand from a peripheral edge portion of the opening 65.

The stator 50 is assembled to the outer peripheral surface of the housing 64. That is, the outer diameter of the housing 64 is the same as the inner diameter of the stator core 52, or slightly smaller than the inner diameter of the stator core 52. The stator 50 and the unit base 61 are integrated by assembling the stator core 52 to the outside of the housing 64. Further, since the unit base 61 is fixed to the housing 30, the stator 50 is integrated with the housing 30 in a state where the stator core 52 is assembled to the case 64.

The stator core 52 is preferably assembled to the unit base 61 by bonding, shrink fitting, press fitting, or the like. Thereby, the stator core 52 is restrained from being displaced in the circumferential direction or the axial direction with respect to the unit base 61 side.

The radially inner side of the housing 64 is a housing space for housing the electrical component 62, and the electrical component 62 is disposed in the housing space so as to surround the rotary shaft 11. The housing 64 functions as a housing space forming portion. The electrical component 62 is constituted by: a semiconductor module 66, a control substrate 67, and a capacitor module 68 that constitute an inverter circuit.

The unit base 61 corresponds to a stator holder (armature holder) that is provided radially inside the stator 50 and holds the stator 50. The housing 30 and the unit base 61 constitute a motor housing of the rotating electric machine 10. In the motor housing described above, the holding member 23 is fixed to the housing 30 on one side in the axial direction with the rotor 40 interposed therebetween, and the housing 30 and the unit base 61 are coupled to each other on the other side. For example, in an electric vehicle or the like as an electric vehicle, the rotating electrical machine 10 is mounted on the vehicle or the like by mounting a motor housing on one side of the vehicle or the like.

Here, the structure of the inverter unit 60 will be further described with reference to fig. 6, which is an exploded view of the inverter unit 60, in addition to fig. 1 to 5.

In the unit base 61, the housing 64 has a cylindrical portion 71 and an end surface 72, and the end surface 72 is provided on one of opposite ends (end portion on the bearing unit 20 side) facing in the axial direction. The opposite side of the end face 72 of the cylindrical portion 71 at both ends in the axial direction is opened over the entire surface by the opening 65 of the end plate 63. A circular hole 73 is formed in the center of the end surface 72, and the rotary shaft 11 is inserted through the hole 73. A seal 171 is provided in the hole 73, and the seal 171 closes a gap between the hole 73 and the outer peripheral surface of the rotary shaft 11. The seal 171 is preferably a sliding seal made of, for example, a resin material.

The cylindrical portion 71 of the housing 64 is a partition portion that partitions between the rotor 40 and the stator 50 disposed on the radially outer side thereof and the electrical component 62 disposed on the radially inner side thereof, and the rotor 40, the stator 50, and the electrical component 62 are disposed so as to be arranged radially inward and outward with the cylindrical portion 71 interposed therebetween.

The electric module 62 is an electric component constituting an inverter circuit, and has a power running function of causing currents to flow in a predetermined order to the respective phase windings of the stator winding 51 to rotate the rotor 40, and a power generating function of inputting a three-phase alternating current flowing to the stator winding 51 with rotation of the rotary shaft 11 and outputting the three-phase alternating current to the outside as generated power. The electric module 62 may have only one of a power running function and a power generating function. For example, when the rotating electrical machine 10 is used as a power source for a vehicle, the power generation function is a regeneration function that outputs regenerated electric power to the outside.

As a specific configuration of the electric module 62, as shown in fig. 4, a capacitor module 68 having a hollow cylindrical shape is provided around the rotary shaft 11, and a plurality of semiconductor modules 66 are arranged in parallel in the circumferential direction on the outer circumferential surface of the capacitor module 68. The capacitor module 68 includes a plurality of smoothing capacitors 68a connected in parallel with each other. Specifically, the capacitor 68a is a stacked film capacitor in which a plurality of film capacitors are stacked, and has a trapezoidal cross section. The capacitor module 68 is configured by annularly arranging twelve capacitors 68a in parallel.

In the manufacturing process of the capacitor 68a, for example, a long film having a predetermined width, which is formed by laminating a plurality of films, is used, the film width direction is set to be the trapezoidal height direction, and the long film is cut into isosceles trapezoids so that the upper base and the lower base of the trapezoid alternate with each other, thereby manufacturing a capacitor element. Then, the capacitor 68a is produced by mounting electrodes and the like on the capacitor element.

The Semiconductor module 66 has a Semiconductor switching element such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor), and is formed in a substantially plate shape. In the present embodiment, the rotating electrical machine 10 includes two sets of three-phase windings, and since an inverter circuit is provided for each three-phase winding, a total of twelve semiconductor modules 66 arranged in a ring form are provided in the electrical component 62 as the semiconductor module group 66A.

The semiconductor module 66 is disposed in a state of being sandwiched between the cylindrical portion 71 of the case 64 and the capacitor module 68. The outer peripheral surface of the semiconductor module group 66A abuts against the inner peripheral surface of the cylindrical portion 71, and the inner peripheral surface of the semiconductor module group 66A abuts against the outer peripheral surface of the capacitor module 68. In this case, heat generated in the semiconductor module 66 is transferred to the end plate 63 through the case 64 and released from the end plate 63.

The semiconductor module group 66A preferably has a spacer 69 between the semiconductor module 66 and the cylindrical portion 71 on the outer peripheral surface side, i.e., in the radial direction. In this case, the cross-sectional shape of the capacitor module 68 in the cross section orthogonal to the axial direction is a regular dodecagon, and the cross-sectional shape of the inner peripheral surface of the cylindrical portion 71 is a circle, so the inner peripheral surface of the spacer 69 is a flat surface and the outer peripheral surface is a curved surface. The spacer 69 may be integrally provided to be connected in an annular shape on the radially outer side of the semiconductor module group 66A. The spacer 69 is preferably a good thermal conductor, such as a metal, e.g., aluminum, or a heat-dissipating gel sheet. The cross-sectional shape of the inner peripheral surface of the cylindrical portion 71 may be a dodecagon similar to the capacitor module 68. In this case, both the inner peripheral surface and the outer peripheral surface of the spacer 69 are preferably flat surfaces.

In the present embodiment, the cooling water passage 74 through which cooling water flows is formed in the cylindrical portion 71 of the housing 64, and the heat generated in the semiconductor module 66 is also released to the cooling water flowing through the cooling water passage 74. That is, the housing 64 includes a water cooling mechanism. As shown in fig. 3 and 4, the cooling water passage 74 is formed in a ring shape so as to surround the electrical components 62 (the semiconductor module 66 and the capacitor module 68). The semiconductor module 66 is disposed along the inner circumferential surface of the cylindrical portion 71, and a cooling water passage 74 is provided at a position overlapping the semiconductor module 66 radially inward and outward.

Since the stator 50 is disposed outside the cylindrical portion 71 and the electric component 62 is disposed inside, heat of the stator 50 is transmitted from outside the cylindrical portion 71 to the cylindrical portion 71 and heat of the electric component 62 (for example, heat of the semiconductor module 66) is transmitted from inside to the cylindrical portion 71. In this case, the stator 50 and the semiconductor module 66 can be cooled simultaneously, so that the heat of the heat generating components in the rotary electric machine 10 can be efficiently released.

At least a part of the semiconductor module 66 constituting a part or all of the inverter circuit for operating the rotating electric machine by supplying current to the stator winding 51 is disposed in a region surrounded by the stator core 52 disposed radially outside the cylindrical portion 71 of the housing 64. Preferably, the entire semiconductor module 66 is disposed in the region surrounded by the stator core 52. More preferably, the entire semiconductor modules 66 are disposed in the region surrounded by the stator core 52.

At least a part of the semiconductor module 66 is disposed in a region surrounded by the cooling water passage 74. Preferably, the entire semiconductor modules 66 are arranged in the region surrounded by the yoke 141.

Further, the electrical component 62 includes: an insulating sheet 75 provided on one end surface of the capacitor module 68 in the axial direction; and a wiring module 76 provided on the other end surface. In this case, the capacitor module 68 has two end faces, i.e., a first end face and a second end face, which are opposite in the above-described axial direction. A first end surface of the capacitor module 68 close to the bearing unit 20 is opposed to an end surface 72 of the case 64, and overlaps the end surface 72 with the insulating sheet 75 interposed therebetween. The wiring module 76 is assembled to the second end face of the capacitor module 68 close to the opening 65.

The wiring module 76 has a main body portion 76a made of a synthetic resin material and having a circular plate shape, and a plurality of bus bars 76b and 76c embedded therein, and is electrically connected to the semiconductor module 66 and the capacitor module 68 via the bus bars 76b and 76 c. Specifically, the semiconductor module 66 has a connection pin 66a extending from an axial end face thereof, and the connection pin 66a is connected to the bus bar 76b radially outside the main body portion 76 a. The bus bar 76c extends radially outward of the main body portion 76a to the opposite side of the capacitor module 68, and is connected at its distal end portion to a wiring member 79 (see fig. 2).

As described above, according to the configuration in which the insulating sheet 75 is provided on the first end surface of the capacitor module 68 facing in the axial direction and the wiring module 76 is provided on the second end surface of the capacitor module 68, a path from the first end surface and the second end surface of the capacitor module 68 to the end surface 72 and the cylindrical portion 71 is formed as a heat radiation path of the capacitor module 68. That is, a path from the first end face to the end face 72 and a path from the second end face to the cylindrical portion 71 are formed. This allows heat to be dissipated from the end surface of the capacitor module 68 other than the outer peripheral surface on which the semiconductor module 66 is provided. I.e. not only in the radial direction but also in the axial direction.

Further, since the capacitor module 68 has a hollow cylindrical shape and the rotary shaft 11 is disposed with a predetermined gap between the inner peripheral portion thereof, the heat of the capacitor module 68 can be released from the hollow portion thereof. In this case, since the air flow is generated by the rotation of the rotary shaft 11, the above-described cooling effect is enhanced.

The disk-shaped control board 67 is mounted on the wiring module 76. The control board 67 has a Printed Circuit Board (PCB) on which a predetermined wiring pattern is formed, and a control device 77 corresponding to a control unit having various ICs, a microcomputer, and the like is mounted on the board. The control board 67 is fixed to the wiring module 76 by a fixing member such as a screw. The control board 67 has an insertion hole 67a in the center thereof through which the rotary shaft 11 is inserted.

In addition, the wiring module 76 has a first face and a second face that are opposed to each other in the axial direction, i.e., opposed to each other in the thickness direction thereof. The first face faces the capacitor module 68. A control board 67 is provided on the second surface of the wiring module 76. The bus bar 76c of the wiring module 76 extends from one side to the other side of both surfaces of the control board 67. In the above configuration, the control board 67 is preferably provided with a notch for avoiding interference with the bus bar 76 c. For example, a part of the outer edge of the control board 67 having a circular shape is preferably cut off.

As described above, the structure in which the electric module 62 is housed in the space surrounded by the case 64 and the housing 30, the rotor 40, and the stator 50 are layered on the outer side thereof can desirably shield the electromagnetic noise generated in the inverter circuit. That is, in the inverter circuit, the switching control in each semiconductor module 66 is performed by PWM control based on a predetermined carrier frequency, and although it is considered that the switching control generates electromagnetic noise, the electromagnetic noise can be desirably shielded by the housing 30, the rotor 40, the stator 50, and the like on the radially outer side of the electrical component 62.

Further, by disposing at least a part of the semiconductor module 66 in the region surrounded by the stator core 52 disposed radially outside the cylindrical portion 71 of the housing 64, even if magnetic flux is generated from the semiconductor module 66, it is less likely to affect the stator winding 51, as compared with a configuration in which the semiconductor module 66 and the stator winding 51 are not disposed across the stator core 52. Even if magnetic flux is generated from the stator winding 51, the semiconductor module 66 is less likely to be affected. Further, it is more effective to dispose the entire semiconductor module 66 in the region surrounded by the stator core 52 disposed radially outside the cylindrical portion 71 of the housing 64. Further, when at least a part of the semiconductor module 66 is surrounded by the cooling water passage 74, an effect is obtained that heat generated from the stator winding 51 and the magnet unit 42 hardly reaches the semiconductor module 66.

In the cylindrical portion 71, a through hole 78 is formed in the vicinity of the end plate 63, and a wiring member 79 (see fig. 2) for electrically connecting the stator 50 on the outer side of the cylindrical portion 71 and the electrical component 62 on the inner side is inserted through the through hole 78. As shown in fig. 2, the wiring members 79 are connected to the end portions of the stator windings 51 and the bus bars 76c of the wiring module 76, respectively, by crimping, welding, or the like. The wiring member 79 is, for example, a bus bar, and the joint surface thereof is preferably flattened. The through-hole 78 is preferably provided at one site or a plurality of sites, and in the present embodiment, the through-hole 78 is provided at two sites. According to the configuration in which the through holes 78 are provided at two locations, the winding terminals extending from the two sets of three-phase windings can be easily wired by the wiring members 79, respectively, and the present invention is suitable for multi-phase wiring.

As described above, in the housing 30, as shown in fig. 4, the rotor 40 and the stator 50 are provided in this order from the radial outside, and the inverter unit 60 is provided on the radial inside of the stator 50. Here, when the radius of the inner circumferential surface of the housing 30 is d, the rotor 40 and the stator 50 are arranged radially outward from the rotational center of the rotor 40 by a distance of d × 0.705. In this case, if a region radially inward from the inner peripheral surface of the stator 50 (i.e., the inner peripheral surface of the stator core 52) of the rotor 40 and the stator 50 is defined as a first region X1 and a region radially between the inner peripheral surface of the stator 50 and the housing 30 is defined as a second region X2, the cross-sectional area of the first region X1 is larger than the cross-sectional area of the second region X2. Further, the volume of the first region X1 is larger than the volume of the second region X2 as viewed in a range where the magnet unit 42 of the rotor 40 and the stator winding 51 overlap in the radial direction.

In addition, when the rotor 40 and the stator 50 are formed as a magnetic circuit assembly, the volume of a first region X1 radially inward from the inner peripheral surface of the magnetic circuit assembly is larger than the volume of a second region X2 radially between the inner peripheral surface of the magnetic circuit assembly and the housing 30 in the housing 30.

Next, the structures of the rotor 40 and the stator 50 will be described in more detail.

In general, as a structure of a stator of a rotating electrical machine, there is known a structure in which a plurality of slots are provided in a circumferential direction in a stator core made of laminated steel plates and having an annular shape, and a stator winding is wound in the slots. Specifically, the stator core has a plurality of pole teeth extending radially from a yoke portion at regular intervals, and a slot is formed between circumferentially adjacent pole teeth. In the slots, for example, a plurality of layers of lead wires are housed in the radial direction, and the stator winding is formed by the lead wires.

However, according to the above-described stator structure, magnetic saturation occurs in the pole teeth of the stator core as the magnetomotive force of the stator winding increases when the stator winding is energized, which is considered to limit the torque density of the rotating electric machine. That is, in the stator core, it is considered that the rotating magnetic flux generated by the energization of the stator winding is concentrated on the pole teeth, and magnetic saturation occurs.

In general, as a structure of an IPM (Interior Permanent Magnet) rotor of a rotating electrical machine, a structure is known in which a Permanent Magnet is disposed on a d-axis and a rotor core is disposed on a q-axis in a d-q coordinate system. In this case, by exciting the stator winding in the vicinity of the d-axis, the excitation magnetic flux flows from the stator into the q-axis of the rotor according to fleming's law. In addition, it is considered that magnetic saturation occurs in a wide range in the q-axis core portion of the rotor.

FIG. 7 is a torque diagram showing a relationship between ampere-turns [ AT ] and torque density [ Nm/L ] of magnetomotive force of a stator winding. The broken line indicates the characteristics of a general IPM rotor type rotating electrical machine. As shown in fig. 7, in a general rotating electric machine, increasing the magnetomotive force in the stator causes magnetic saturation in two portions, the tooth portion and the q-axis core portion between the slots, and thus increases in torque are restricted. Thus, in the above-described general rotating electrical machine, the ampere-turn scheme value is limited to a 1.

Therefore, in the present embodiment, in order to overcome the limitation caused by the magnetic saturation, the following configuration is provided in the rotating electrical machine 10. That is, as the first means, in order to eliminate magnetic saturation occurring at the pole teeth of the stator core in the stator, the stator 50 has a grooveless structure, and in order to eliminate magnetic saturation occurring at the q-axis core portion of the IPM rotor, an SPM (Surface Permanent Magnet) rotor is used. According to the first aspect, although the two portions where magnetic saturation occurs can be eliminated, it is considered that the torque in the low current region is reduced (see the chain line in fig. 7). Therefore, as a second aspect, in order to recover the torque reduction by enhancing the magnetic flux of the SPM rotor, a structure is adopted in the magnet unit 42 of the rotor 40 in which the magnetic flux path of the magnet is lengthened to increase the polar anisotropy of the magnetic force.

Further, as a third aspect, a flat wire structure that makes the radial thickness in the stator 50 of the wire smaller is adopted in the coil side portion 53 of the stator winding 51 to recover the reduction of the torque. Here, it is considered that the polar anisotropy structure that enhances the magnetic force generates a larger eddy current in the stator winding 51 facing the magnet unit 42. However, according to the third aspect, since it is a flat wire structure that is thin in the radial direction, it is possible to suppress generation of eddy current in the radial direction in the stator winding 51. As described above, according to the first to third configurations, as shown by the solid line in fig. 7, the torque characteristics can be greatly improved by using the magnet having a high magnetic force, and the possibility that the magnet having a high magnetic force causes a large eddy current can be reduced.

Further, as a fourth aspect, a magnet unit is employed which utilizes a polar anisotropic structure and has a magnetic flux density distribution close to a sine wave. This makes it possible to enhance torque by increasing the sine wave matching rate by pulse control or the like described later, and further suppress eddy current loss (copper loss due to eddy current) because the magnetic flux changes more gently than in the radial magnet.

The sine wave matching rate will be described below. The sine wave matching rate can be obtained by comparing an actually measured waveform of the surface magnetic flux density distribution measured by tracing the surface of the magnet or the like with the magnetic flux probe with a sine wave having the same period and peak value. The ratio of the amplitude of the primary waveform, which is the fundamental wave of the rotating electric machine, to the amplitude of the actually measured waveform, that is, the amplitude obtained by adding the other harmonic component to the fundamental wave corresponds to the sine wave matching ratio. As the sine wave matching rate becomes higher, the waveform of the surface magnetic flux density distribution gradually approaches the sine wave shape. Further, when a current of a primary sine wave is supplied from the inverter to the rotating electric machine including the magnet having the improved sine wave matching rate, the waveform of the surface magnetic flux density distribution of the magnet can be made close to a sine wave shape, and a large torque can be generated. The surface magnetic flux density distribution can also be estimated by a method other than actual measurement, for example, electromagnetic field analysis using maxwell's equations.

Further, as a fifth aspect, the stator winding 51 is provided as a wire conductor structure in which a plurality of wires are gathered and bundled. Thereby, since the wires are connected in parallel, a large current can flow, and since the respective cross-sectional areas of the wires become small, it is possible to more effectively suppress the generation of eddy current at the wire spreading in the circumferential direction of the stator 50 in the flat wire structure, as compared with the third scheme of thinning in the radial direction. Further, since the plurality of strands are twisted, eddy current according to the magnetic flux generated according to the right-hand rule with respect to the current flowing direction can be cancelled with respect to the magnetomotive force from the conductor.

In this way, when the fourth aspect and the fifth aspect are further added, while the magnet of the second aspect having a high magnetic force is employed, it is possible to further suppress eddy current loss caused by the above-described high magnetic force and achieve torque enhancement.

Hereinafter, the non-slotted structure of the stator 50, the flat wire structure of the stator winding 51, and the polar anisotropy structure of the magnet unit 42 will be described in an increasing manner. First, the non-slotted structure of the stator 50 and the flat wire structure of the stator winding 51 will be described. Fig. 8 is a cross-sectional view of the rotor 40 and the stator 50, and fig. 9 is an enlarged view of a part of the rotor 40 and the stator 50 shown in fig. 8. Fig. 10 is a sectional view showing a cross section of the stator 50 along the X-X line of fig. 11, and fig. 11 is a sectional view showing a longitudinal section of the stator 50. Fig. 12 is a perspective view of the stator winding 51. In fig. 8 and 9, the magnetization direction of the magnet in the magnet unit 42 is indicated by an arrow.

As shown in fig. 8 to 11, the stator core 52 is formed in a cylindrical shape having a predetermined thickness in the radial direction and a plurality of electromagnetic steel sheets are stacked in the axial direction, and the stator winding 51 is assembled on the radial outer side of the stator core 52 on the rotor 40 side. An outer peripheral surface of the stator core 52 facing the rotor 40 is a lead wire installation portion (conductor region). The outer peripheral surface of the stator core 52 is formed into a curved surface without unevenness, and a plurality of lead groups 81 are arranged on the outer peripheral surface at predetermined intervals in the circumferential direction. The stator core 52 functions as a back yoke that forms a part of a magnetic path for rotating the rotor 40. In this case, a structure in which no pole teeth (i.e., cores) made of a soft magnetic material are provided between each of the two circumferentially adjacent conductor sets 81 (i.e., a non-slotted structure) is obtained. In the present embodiment, the resin material constituting the sealing member 57 enters the gap 56 of each lead group 81. That is, in the stator 50, the inter-conductor members provided between the respective conductor groups 81 in the circumferential direction are configured as the sealing member 57 of a non-magnetic material. In the state before the sealing of the sealing member 57, the conductor groups 81 are arranged at predetermined intervals in the circumferential direction outside the stator core 52 in the radial direction so as to separate the gaps 56, which are the inter-conductor regions, respectively, thereby forming the stator 50 having the non-slotting structure. In other words, as will be described later, each of the lead groups 81 is constituted by two lead wires (conductors) 82, and each of the two lead groups 81 adjacent in the circumferential direction of the stator 50 is occupied only by the nonmagnetic material therebetween. The nonmagnetic material includes a nonmagnetic gas such as air, a nonmagnetic liquid, and the like in addition to the sealing member 57. Hereinafter, the seal member 57 is also referred to as a conductor-to-conductor member (conductor-to-conductor member).

The structure in which the pole teeth are provided between the respective conductor groups 81 arranged in the circumferential direction is a structure in which the pole teeth have a predetermined thickness in the radial direction and a predetermined width in the circumferential direction, and a magnetic path of the magnet, which is a part of the magnetic path, is formed between the respective conductor groups 81. In this regard, the structure in which no pole teeth are provided between the lead wire groups 81 means the structure in which the magnetic circuit is not formed.

As shown in fig. 10, the stator winding (i.e., the armature winding) 51 is formed to have a predetermined thickness T2 (hereinafter also referred to as a first dimension) and a width W2 (hereinafter also referred to as a second dimension). The thickness T2 is the shortest distance between the outer side surface and the inner side surface of the stator winding 51 that are opposite to each other in the radial direction. The width W2 is the length in the circumferential direction of the stator winding 51 that is a part of the stator winding 51 that functions as one of the multiple phases (three phases in the embodiment: three phases of U, V, and W, or three phases of X, Y, and Z) of the stator winding 51. Specifically, in fig. 10, when two lead wire groups 81 adjacent in the circumferential direction function as, for example, a U-phase which is one of three phases, the width W2 is a width from one end to the other end of the two lead wire groups 81 in the circumferential direction. Also, the thickness T2 is less than the width W2.

In addition, the thickness T2 is preferably less than the total width dimension of the two lead groups 81 present within the width W2. When the cross-sectional shape of the stator winding 51 (more specifically, the lead wires 82) is a perfect circle shape, an ellipse shape, or a polygon shape, the maximum length of the lead wires 82 in the radial direction of the stator 50 in the cross section along the radial direction of the stator 50 may be W12, and the maximum length of the stator 50 in the circumferential direction in the cross section may be W11.

As shown in fig. 10 and 11, the stator winding 51 is sealed by a sealing member 57, and the sealing member 57 is made of a synthetic resin material as a sealing material (molding material). That is, the stator winding 51 and the stator core 52 are molded together by a molding material. The resin can be regarded as Bs 0 as a nonmagnetic substance or a nonmagnetic equivalent.

As seen in the cross section of fig. 10, the sealing member 57 is provided by filling the gaps 56 between the lead groups 81 with a synthetic resin material, and an insulating member is interposed between the lead groups 81 through the sealing member 57. That is, the seal member 57 functions as an insulating member in the gap 56. The seal member 57 is provided radially outside the stator core 52 in a range including all the respective lead groups 81, that is, in a range having a radial thickness dimension larger than that of the respective lead groups 81.

Further, as viewed in the longitudinal section of fig. 11, the seal member 57 is provided in a range including the turn portion 84 of the stator winding 51. On the radially inner side of the stator winding 51, a seal member 57 is provided in a range including at least a part of the axially opposite end surfaces of the stator core 52. In this case, the stator winding 51 is sealed with resin substantially entirely except for the end portions of the phase windings of the respective phases, that is, the connection terminals connected to the inverter circuit.

According to the structure in which the seal member 57 is provided in the range including the end face of the stator core 52, the laminated steel plates of the stator core 52 can be pressed inward in the axial direction by the seal member 57. This enables the stacked state of the steel plates to be maintained by the seal member 57. Although the inner peripheral surface of the stator core 52 is not resin-sealed in the present embodiment, the entire stator core 52 including the inner peripheral surface of the stator core 52 may be resin-sealed.

When the rotating electric machine 10 is used as a vehicle power source, the seal member 57 is preferably made of a highly heat-resistant fluororesin, an epoxy resin, a PPS resin, a PEEK resin, an LCP resin, a silicone resin, a PAI resin, a PI resin, or the like. In addition, when considering the linear expansion coefficient from the viewpoint of suppressing cracking due to the expansion difference, it is desirable that the material be the same as the outer film of the lead wire of the stator winding 51. That is, it is desirable to exclude silicone resins whose linear expansion coefficient is generally a multiple or more of that of other resins. Among electric products such as electric vehicles which do not have a device using combustion, PP0 resin, phenol resin, and FRP resin having heat resistance of about 180 ℃ are also candidates. In the field where the ambient temperature of the rotating electric machine is regarded as lower than 100 ℃, there is no limitation described above.

The torque of the rotating electrical machine 10 is proportional to the magnitude of the magnetic flux. Here, when the stator core has the pole teeth, the maximum magnetic flux at the stator depends on and is limited to the saturation magnetic flux density at the pole teeth, but when the stator core does not have the pole teeth, the maximum magnetic flux at the stator is not limited. Therefore, it is advantageous in increasing the energization current to the stator winding 51 to achieve an increase in the torque of the rotary electric machine 10.

In the present embodiment, the inductance of the stator 50 is reduced by using a structure without pole teeth (a non-slotting structure) in the stator 50. Specifically, in a stator of a general rotating electrical machine in which a lead wire is accommodated in each slot partitioned by a plurality of pole teeth, the inductance is, for example, about 1mH, whereas the inductance is reduced to about 5 to 60 μ H in the stator 50 of the present embodiment. In the present embodiment, the mechanical time constant Tm can be reduced by reducing the inductance of the stator 50 while providing the rotating electric machine 10 having an outer rotor structure. That is, the mechanical time constant Tm can be reduced while achieving high torque. In addition, the mechanical time constant Tm is calculated by the following equation, where J is inertia, L is inductance, Kt is a torque constant, and Ke is a back electromotive force constant.

Tm＝(J×L)/(Kt×Ke)

In this case, it was confirmed that the mechanical time constant Tm can be reduced by reducing the inductance L.

A plurality of lead wires 82 having a flat rectangular cross section are arranged in a radial direction of the stator core 52, thereby constituting each lead wire group 81 on the outer side in the radial direction of the stator core 52. Each of the wires 82 is arranged in a direction of "radial dimension < circumferential dimension" in cross section. This realizes a radial thinning of each lead group 81. Further, the conductor region is extended flatly to the region having the conventional pole teeth while achieving the radial thinning, and the flat wire region structure is obtained. Thus, the sectional area of the conductor is increased by flattening in the circumferential direction, and an increase in the amount of heat generation of the lead wire due to the reduction in the sectional area by thinning is suppressed. Even in the configuration in which a plurality of strands of wires are arranged in the circumferential direction and the wires are connected in parallel, a decrease in the conductor cross-sectional area due to the portion of the conductor film occurs, but the same effect can be obtained for the same reason. In addition, hereinafter, each of the lead group 81 and each of the leads 82 is also referred to as a conductive member (conductive member).

Since there is no slot, according to the stator winding 51 of the present embodiment, the conductor area occupied by the stator winding 51 of one circumferential circle thereof can be designed to be larger than the nonconductor occupied area where the stator winding 51 is not present. In addition, in the conventional rotating electric machine for a vehicle, the conductor area/nonconductor occupying area of one circumferential periphery of the stator winding is naturally 1 or less. On the other hand, in the present embodiment, each of the lead groups 81 is provided so that the conductor area is equal to the non-conductor occupying area or the conductor area is larger than the non-conductor occupying area. Here, as shown in fig. 10, when a conductor area in which the conductors 82 (i.e., a straight portion 83 described later) are arranged in the circumferential direction is WA and an inter-conductor area between adjacent conductors 82 is WB, the conductor area WA is larger than the inter-conductor area WB in the circumferential direction.

As a structure of the lead group 81 of the stator winding 51, a thickness dimension in a radial direction of the lead group 81 is smaller than a width dimension in a circumferential direction corresponding to one of the magnetic poles. That is, in the configuration in which the lead group 81 is composed of two layers of leads 82 in the radial direction, and two lead groups 81 are provided in the circumferential direction for one phase in one magnetic pole, when the radial thickness of each lead 82 is Tc and the circumferential width of each lead 82 is Wc, the configuration is "Tc × 2 < Wc × 2". As another configuration, in a configuration in which the lead group 81 is formed of two layers of leads 82 and one lead group 81 is provided in the circumferential direction for one phase in one magnetic pole, it is preferable to set the relationship "Tc × 2 < Wc". In short, the radial thickness dimension of the lead portions (lead group 81) arranged at predetermined intervals in the circumferential direction in the stator winding 51 is smaller than the circumferential width dimension corresponding to one of the magnetic poles.

In other words, the radial thickness dimension Tc of each strand 82 is preferably smaller than the circumferential width dimension Wc. Further, the radial thickness dimension (2Tc) of the lead group 81 composed of the two layers of leads 82 in the radial direction, that is, the radial thickness dimension (2Tc) of the lead group 81 is preferably smaller than the circumferential width dimension Wc.

The torque of the rotating electrical machine 10 is approximately inversely proportional to the radial thickness of the stator core 52 of the lead group 81. In this regard, the thickness of the lead wire group 81 is reduced on the radially outer side of the stator core 52, which is advantageous in that the torque of the rotating electrical machine 10 is increased. The reason is that the distance from the magnet unit 42 of the rotor 40 to the stator core 52 (i.e., the distance of the portion without iron) can be reduced, thereby reducing the magnetic resistance. This can increase the interlinkage magnetic flux between the permanent magnet and the stator core 52, and can increase the torque.

Further, by making the thickness of the lead group 81 thin, even if magnetic flux leaks from the lead group 81, it can be easily recovered to the stator core 52, and leakage of magnetic flux to the outside can be suppressed and is not effectively used for torque improvement. That is, a decrease in magnetic force due to leakage of magnetic flux can be suppressed, and the interlinkage magnetic flux between the permanent magnet and the stator core 52 can be increased to enhance torque.

The lead wires 82 (conductors) are formed of covered lead wires in which the surfaces of the conductors (conductor bodies) 82a are covered with an insulating film 82b, so that insulation is secured between the lead wires 82 that overlap each other in the radial direction and between the lead wires 82 and the stator core 52, respectively. If the wire 86 described later is a self-fluxing covered wire, the insulating film 82b is a covering film thereof, or is formed of an insulating member that is different from and overlaps the covering film of the wire 86. In addition, the phase windings of the lead wires 82 are insulated by the insulating film 82b except for the exposed portions for connection. The exposed portion is, for example, an input/output terminal portion or a neutral point portion when forming a star connection. In the lead group 81, the leads 82 adjacent in the radial direction are fixed to each other by resin fixation or self-fluxing coating. Thereby, insulation breakdown, vibration, and sound caused by the wires 82 rubbing against each other are suppressed.

In the present embodiment, the conductor 82a is configured as an aggregate of a plurality of strands of wire (wire) 86. Specifically, as shown in fig. 13, the conductor 82a is formed into a twisted shape by twisting a plurality of strands of wire 86. As shown in fig. 14, the wire 86 is a composite body formed by bundling thin fiber-shaped conductive members 87. For example, the wire 86 is a composite of CNT (carbon nanotube) fibers, and as the CNT fibers, fibers including boron-containing microfibers in which at least a part of carbon is replaced with boron are used. As the carbon microfine fibers, in addition to the CNT fibers, Vapor Growth Carbon Fibers (VGCF) and the like can be used, but the CNT fibers are preferably used. The surface of the wire 86 is covered with a polymer insulating layer such as enamel. Further, the surface of the wire 86 is preferably covered with a so-called enamel film composed of a film of polyimide, a film of amide imide.

The wires 82 constitute n-phase windings in the stator winding 51. Also, the respective wires 86 of the lead wires 82 (i.e., the conductors 82a) are adjacent in a state of contact with each other. The lead 82 is a wire assembly in which the winding conductor has a portion formed by twisting a plurality of wires 86 at one or more portions within a phase, and the resistance value between the twisted wires 86 is larger than the resistance value of the wires 86 themselves. In other words, when each of the two adjacent strands 86 has a first resistivity in its adjacent direction and each of the strands 86 has a second resistivity in its longitudinal direction, the first resistivity is a value larger than the second resistivity. The lead wire 82 may be a wire assembly of: is formed of a plurality of strands 86 and the plurality of strands 86 are covered with a first extremely high resistivity insulating member. Further, the conductor 82a of the wire 82 is constituted by twisted strands 86.

Since the conductor 82a is formed by twisting a plurality of strands of the wires 86, it is possible to reduce the eddy current of the conductor 82a while suppressing the generation of the eddy current in each wire 86. Further, by twisting the respective wires 86, portions in which the directions of application of the magnetic fields are opposite to each other are generated in one wire 86, and the counter electromotive force is cancelled out. Therefore, eddy current can still be reduced. In particular, by forming the wire 86 with the fibrous conductive member 87, the number of twists can be increased greatly while thinning the wire, and the eddy current can be further reduced desirably.

The method of insulating the wires 86 from each other is not limited to the above-described polymer insulating film, and a method of making it difficult for current to flow between the twisted wires 86 by contact resistance may be used. That is, if the resistance value between the twisted wires 86 is larger than the resistance value of the wires 86 themselves, the above-described effect can be obtained by the potential difference generated by the difference in the resistance values. For example, it is preferable that the manufacturing equipment for manufacturing the wire 86 and the manufacturing equipment for manufacturing the stator 50 (armature) of the rotating electrical machine 10 be used as separate discontinuous equipment, so that the wire 86 is oxidized according to the moving time, the working interval, and the like, thereby increasing the contact resistance.

As described above, the lead wire 82 is a member having a flat rectangular cross section and a plurality of wires arranged in parallel in the radial direction, and maintains the shape by gathering the stranded wires 86, which are covered with the self-melting covered wire including the fusion layer and the insulating layer, in a twisted state and fusing the fusion layers to each other. The wire rod not including the fusion layer or the self-fusible coated wire may be twisted and cured with a synthetic resin or the like into a desired shape. When the thickness of the insulating film 82b of the lead wire 82 is set to be, for example, 80 to 100 μm, which is thicker than the thickness (5 to 40 μm) of a lead wire used in general, insulation between the lead wire 82 and the stator core 52 can be ensured even if an insulating paper or the like is not interposed between the lead wire 82 and the stator core 52.

Further, it is desirable that the insulating film 82b has a higher insulating performance than the insulating layer of the wire 86, and can insulate the phases from each other. For example, when the thickness of the polymer insulating layer of the wire 86 is about 5 μm, for example, it is desirable that the thickness of the insulating film 82b of the lead 82 is about 80 μm to 100 μm, so that the insulation between the phases can be preferably performed.

The lead 82 may be configured to bundle the plurality of wires 86 without twisting. That is, the lead 82 may have any structure in which the plurality of strands 86 are twisted over the entire length thereof, a structure in which the plurality of strands 86 are twisted over a part of the entire length thereof, or a structure in which the plurality of strands 86 are bundled without being twisted over the entire length thereof. In short, each of the leads 82 constituting the lead portion is a wire assembly of: the plurality of wires 86 are bundled and the resistance value between the bundled wires is larger than the resistance value of the wires 86 themselves.

Each of the lead wires 82 is formed by bending and arranged in a predetermined arrangement pattern in the circumferential direction of the stator winding 51, thereby forming a phase winding for each phase as the stator winding 51. As shown in fig. 12, in the stator winding 51, the coil side portions 53 are formed by straight portions 83 extending linearly in the axial direction in the respective lead wires 82, and the coil side end portions 54, 55 are formed by bent portions 84 protruding outward in the axial direction on both sides of the coil side portions 53. The straight portions 83 and the bent portions 84 are alternately repeated, and each of the conductive wires 82 is configured as a series of conductive wires having a waveform. The straight portions 83 are disposed at positions radially opposed to the magnet unit 42, and the straight portions 83 of the same phase disposed at positions axially outward of the magnet unit 42 with a predetermined interval therebetween are connected to each other by a bent portion 84. The linear portion 83 corresponds to a "magnet opposing portion".

In the present embodiment, the stator winding 51 is formed by winding in a distributed winding manner in an annular shape. In this case, the linear portions 83 are arranged at intervals corresponding to one pole of the magnet unit 42 in the circumferential direction for each phase in the coil side portion 53, and the linear portions 83 of each phase are connected to each other by the bent portion 84 formed in a substantially V-shape in the coil side end portions 54, 55. The directions of currents of the respective linear portions 83 paired with one pole pair are opposite to each other. In addition, the combination of the pair of straight portions 83 connected by the bent portions 84 differs between the one coil side end portion 54 and the other coil side end portion 55, and the stator winding 51 is formed into a substantially cylindrical shape by repeating the connection at the coil side end portions 54, 55 in the circumferential direction.

More specifically, the stator winding 51 is formed by winding each phase using two pairs of lead wires 82 for each phase, and one three-phase winding (U-phase, V-phase, W-phase) and the other three-phase winding (X-phase, Y-phase, Z-phase) of the stator winding 51 are provided at two radially inner and outer layers. In this case, when the number of phases of the stator winding 51 is S (6 in the embodiment) and the number of the lead wires 82 per phase is m, 2 × S × m — 2Sm lead wires 82 are formed for each pole pair. In the present embodiment, since the rotating electric machine has 6 phases S, 4 numbers m, and 8 pole pairs (16 poles), the 6 × 4 × 8-192-strand wires 82 are arranged in the circumferential direction of the stator core 52.

The stator winding 51 shown in fig. 12 is configured such that, in the coil side portion 53, straight portions 83 are arranged to overlap two radially adjacent layers, and in the coil side end portions 54, 55, return portions 84 extend in the circumferential direction in mutually opposite directions in the circumferential direction from the respective straight portions 83 overlapping in the radial direction. That is, in each of the conductive wires 82 adjacent in the radial direction, the directions of the return portions 84 are opposite to each other except for the end portions of the stator winding 51.

Here, a winding structure of the wire 82 in the stator winding 51 will be specifically described. In the present embodiment, the plurality of conductive wires 82 formed by wave winding are arranged so that a plurality of layers (for example, two layers) adjacent in the radial direction overlap. Fig. 15 (a) and 15 (b) are views showing the form of each lead wire 82 of the n-th layer, fig. 15 (a) shows the shape of the lead wire 82 as viewed from the side of the stator winding 51, and fig. 15 (b) shows the shape of the lead wire 82 as viewed from one axial side of the stator winding 51. In fig. 15 (a) and 15 (b), positions where the lead group 81 is arranged are indicated as D1, D2, and D3 …, respectively. For convenience of explanation, only three wires 82 are shown, and the first wire 82_ a, the second wire 82_ B, and the third wire 82_ C are used.

In each of the conductive wires 82_ a to 82_ C, the straight portions 83 are arranged at the position of the nth layer, that is, at the same position in the radial direction, and the straight portions 83 separated at 6 positions (corresponding to 3 × m pairs) in the circumferential direction are connected to each other by the bent portions 84. In other words, in each of the lead wires 82_ a to 82_ C, two of both ends of seven linear portions 83 arranged adjacent to each other in the circumferential direction of the stator winding 51 are connected to each other by one bent portion 84 on the same circle centered on the axial center of the rotor 40. For example, in the first lead 82_ a, a pair of straight portions 83 are disposed at D1 and D7, respectively, and the pair of straight portions 83 are connected to each other by an inverted V-shaped return portion 84. The other conductive wires 82_ B and 82_ C are arranged in the same nth layer so as to be shifted by one position in the circumferential direction. In this case, since the lead wires 82_ a to 82_ C are all disposed on the same layer, the return portions 84 are considered to interfere with each other. Therefore, in the present embodiment, the interference avoiding portion is formed in the turn portion 84 of each of the conductive wires 82_ a to 82_ C so as to partially offset in the radial direction.

Specifically, the bent portion 84 of each of the lead wires 82_ a to 82_ C includes: one inclined portion 84a as a portion extending in the circumferential direction on the same circle (first circle); a position shifted from the inclined portion 84a to a radially inner side (upper side in fig. 15 b) of the same circle and reaching the apex portion 84b of the other circle (second circle); an inclined portion 84c extending in the circumferential direction on the second circle; and a return portion 84d from the first circle to the second circle. The apex portion 84b, the inclined portion 84c, and the return portion 84d correspond to an interference avoiding portion. The inclined portion 84c may be radially outwardly offset from the inclined portion 84 a.

That is, the bent portions 84 of the respective lead wires 82_ a to 82_ C have one inclined portion 84a and the other inclined portion 84C on both sides thereof with respect to the top portion 84b, which is the circumferential central position, and the radial positions (the position in the front-rear direction of the paper in fig. 15 a, and the position in the up-down direction in fig. 15 b) of the inclined portions 84a and 84C are different from each other. For example, the bent portion 84 of the first lead wire 82_ a extends in the circumferential direction with the D1 position of the n layers as a starting position, is bent in the radial direction (for example, radially inward) at the apex portion 84b, which is the circumferential central position, and is then bent in the circumferential direction again, thereby extending in the circumferential direction again, and is further bent in the radial direction (for example, radially outward) at the return portion 84D, thereby reaching the D7 position of the n layers, which is the end position.

According to the above configuration, the conductive wires 82_ a to 82_ C are configured such that the inclined portions 84a on one side are arranged vertically in the order of the first conductive wire 82_ a → the second conductive wire 82_ B → the third conductive wire 82_ C from above, and the upper and lower portions of the conductive wires 82_ a to 82_ C are switched at the apex portion 84B, and the inclined portions 84C on the other side are arranged vertically in the order of the third conductive wire 82_ C → the second conductive wire 82_ B → the first conductive wire 82_ a from above. Therefore, the conductive wires 82_ a to 82_ C can be arranged in the circumferential direction without interfering with each other.

Here, in the configuration in which the plurality of lead wires 82 are stacked in the radial direction to form the lead wire group 81, the return portion 84 connected to the straight portion 83 on the radially inner side among the straight portions 83 in the plurality of layers and the return portion 84 connected to the straight portion 83 on the radially outer side are preferably arranged to be further apart from each other in the radial direction than the straight portions 83. When the multilayer conductive wires 82 are bent radially on the same side at the end of the bent portion 84, that is, near the boundary portion of the straight portion 83, it is preferable that the insulation is not damaged by the interference between the conductive wires 82 of the adjacent layers.

For example, in D7 to D9 in fig. 15 (a) and 15 (b), the respective lead wires 82 that overlap in the radial direction are bent in the radial direction at the return portions 84D of the return portions 84, respectively. In this case, as shown in fig. 16, it is preferable that the curvature radii of the curved portions of the wire 82 of the nth layer and the wire 82 of the (n + 1) th layer are different. Specifically, the radius of curvature R1 of the wire 82 on the radially inner side (nth layer) is made smaller than the radius of curvature R2 of the wire 82 on the radially outer side (n +1 st layer).

In addition, it is preferable that the amount of radial offset of the wire 82 of the nth layer and the wire 82 of the (n + 1) th layer is different. Specifically, the amount of offset S1 of the wire 82 on the radially inner side (nth layer) is made larger than the amount of offset S2 of the wire 82 on the radially outer side (n +1 st layer).

According to the above structure, even in the case where the respective conductive wires 82 overlapped in the radial direction are bent in the same direction, the mutual interference of the respective conductive wires 82 can be desirably avoided. This provides excellent insulation.

Next, the structure of the magnet unit 42 in the rotor 40 will be described. In the present embodiment, it is assumed that the magnet unit 42 is formed of a permanent magnet, and the residual magnetic flux density Br is 1.0[ T ] and the intrinsic coercive force Hcj is 400[ kA/m ] or more. In short, the permanent magnet used in the present embodiment is a sintered magnet obtained by sintering a granular magnetic material and molding and solidifying the sintered magnet, and the intrinsic coercive force Hcj on the J-H curve is 400[ kA/m ] or more, and the residual magnetic flux density Br is 1.0[ T ] or more. When 5000 to 10000[ AT ] is applied by the inter-phase excitation, if a permanent magnet is used in which the magnetic length of N and S poles, which are one pole pair, in other words, the length of 25[ mm ] passing through the magnet in a path through which magnetic flux flows between the N and S poles, Hcj is 10000[ A ], and demagnetization is not caused.

In other words, regarding the magnet unit 42, the saturation magnetic flux density Js is 1.2[ T ] or more and the crystal grain size is 10[ μm ] or less, and Js × α is 1.0[ T ] or more when the orientation ratio is α.

The magnet unit 42 will be described supplementarily below. The magnet unit 42 (magnet) is characterized in that 2.15[ T ] or more Js or more 1.2[ T ]. In other words, as the magnet used for the magnet unit 42, NdFe11TiN, Nd2Fe14B, Sm2Fe17N3, FeNi magnet having L10 type crystal, and the like are cited. Further, the structure of SmCo5, FePt, Dy2Fe14B, CoPt, etc., which is generally called a samarium-cobalt magnet (samarium-cobalt) cannot be used. It should be noted that although there are cases where dysprosium, which is a heavy rare earth, is generally used, such as Dy2Fe14B and Nd2Fe14B, which are compounds of the same type, and the high Js characteristic of neodymium is somewhat lost, magnets having a high coercive force possessed by Dy can also satisfy 2.15T ≧ Js ≧ 1.2T, and can also be used in such cases. In this case, it is referred to as, for example, ([ Nd1-xDyx ]2Fe 14B). Further, a magnet made of two or more kinds of magnets having different compositions, for example, a magnet made of two or more kinds of materials such as FeNi + Sm2Fe17N3, may be used, or a mixed magnet in which a small amount of, for example, Dy2Fe14B having Js < 1[ T ] is mixed with a magnet of Nd2Fe14B having Js excess such as Js of 1.6[ T ] to increase coercive force may be used.

Further, for a rotating electrical machine that operates at a temperature outside the range of human activity, for example, 60 ℃ or higher exceeding the temperature of a desert, for example, for a vehicle motor application in which the interior temperature of the vehicle approaches 80 ℃ in summer, a component including FeNi or Sm2Fe17N3 having a small temperature dependence coefficient is particularly desirable. This is because, in motor operation from a temperature state in the neighborhood of-40 ℃ in northern europe, which is a range of human activity, to the above-mentioned temperature of 60 ℃ or more exceeding the desert temperature, or to the heat-resistant temperature of the coil enamel film of about 180 to 240 ℃, the motor characteristics greatly differ depending on the temperature dependence coefficient, and therefore, it is difficult to perform optimal control by the same motor driver, and the like. When FeNi or Sm2Fe17N3 having the L10 type crystal is used, the load on the motor driver can be reduced more than half by the characteristic of having a temperature dependence coefficient of not more than half as compared with Nd2Fe 14B.

In addition, the magnet unit 42 is characterized in that the size of the particle diameter in a fine powder state before orientation is 10 μm or less and the single domain particle diameter is 10 μm or more by using the above magnet combination. In a magnet, the coercive force can be increased by making the particles of the powder finer to the order of several hundred nm, and therefore, in recent years, as much as possible, finer powder is used. However, if the grain size is too small, the BH product of the magnet is reduced by oxidation or the like, and therefore, the single domain particle diameter or more is preferable. It is known that the coercivity increases by miniaturization of the particle diameter up to the single domain particle diameter. The particle diameter described here is the particle diameter in a fine powder state in the orientation step in the production process of the magnet.

Further, the first magnet 91 and the second magnet 92 of the magnet unit 42 are respectively sintered magnets formed by firing magnetic powder at a high temperature, that is, by so-called sintering. In this sintering, the magnet unit 42 is sintered under the condition that the saturation magnetic flux density Js is 1.2T or more, the crystal grain diameters of the first magnet 91 and the second magnet 92 are 10 μm or less, and the orientation ratio α satisfies Js × α of 1.0T (tesla) or more. Further, the first and second magnets 91 and 92 are sintered so as to satisfy the following conditions, respectively. Next, the isotropic magnetic material is oriented in the orientation step in the above-described production step, and has an orientation ratio (orientation ratio) different from the definition of the magnetic force direction in the magnetization step of the isotropic magnetic material. The magnetic unit 42 of the present embodiment has a saturation magnetic flux density Js of 1.2T or more, and a high orientation ratio is set so that the orientation ratio α of the first and second magnetic bodies 91 and 92 is Jr.gtoreq.alphais.gtoreq.1.0 [ T ]. The orientation factor α here means that, in the first magnet 91 or the second magnet 92, when, for example, there are 6 easy magnetization axes, five of which are oriented in the same direction, i.e., the direction a10, and the remaining one is oriented in the direction B10 inclined by 90 degrees with respect to the direction a10, α is 5/6, and when the remaining one is oriented in the direction B10 inclined by 45 degrees with respect to the direction a10, α is (5+0.707)/6 because the component oriented in the direction a10 of the remaining one is cos45 ° -0.707. Although the first and second magnetic bodies 91 and 92 are formed by sintering in the present embodiment, the first and second magnetic bodies 91 and 92 may be formed by other methods if the above conditions are satisfied. For example, a method of forming the MQ3 magnet or the like may be employed.

In the present embodiment, since the permanent magnet whose axis of easy magnetization is controlled by orientation is used, the magnetic path length inside the magnet can be made longer than that of a conventional linearly oriented magnet having 1.0[ T ] or more. That is, in addition to the magnetic path length per pole pair being realized with a small amount of magnet, the reversible demagnetization range can be maintained even when exposed to severe high temperature conditions, as compared with the design using the conventional linearly oriented magnet. Further, the inventors of the present application have found a structure that can obtain characteristics close to those of a polar anisotropic magnet even when a magnet of the related art is used.

The easy axis means a crystal orientation that is easily magnetized in a magnet. The direction of the easy magnetization axis in the magnet is a direction in which the orientation rate indicating the degree of alignment of the direction of the easy magnetization axis is 50% or more, or a direction in which the orientation of the magnet is averaged.

As shown in fig. 8 and 9, the magnet unit 42 is annular and is provided inside the magnet holder 41 (specifically, radially inside the cylindrical portion 43). The magnet unit 42 has a first magnet 91 and a second magnet 92 which are respectively polar anisotropic magnets and have mutually different polarities. The first magnets 91 and the second magnets 92 are alternately arranged in the circumferential direction. The first magnet 91 is a magnet having an N pole formed at a portion close to the stator winding 51, and the second magnet 92 is a magnet having an S pole formed at a portion close to the stator winding 51. The first magnet 91 and the second magnet 92 are permanent magnets made of rare earth magnets such as neodymium magnets.

In each of the magnets 91 and 92, as shown in fig. 9, in a known d-q coordinate system, the magnetization direction extends in an arc shape between a d-axis (direct-axis) which is a magnetic pole center and a q-axis (orthogonal axis) which is a magnetic pole boundary between the N-pole and the S-pole (in other words, the magnetic flux density is 0 tesla). In each of the magnets 91 and 92, the magnetization direction is the radial direction of the annular magnet unit 42 on the d-axis side, and the magnetization direction of the annular magnet unit 42 is the circumferential direction on the q-axis side. The following further describes the details. As shown in fig. 9, the magnets 91 and 92 each have: a first portion 250; and two second portions 260 located on both sides of the first portion 250 in the circumferential direction of the magnet unit 42. In other words, the first portion 250 is closer to the d-axis than the second portion 260, and the second portion 260 is closer to the q-axis than the first portion 250. Also, the magnet unit 42 is configured such that the direction of the magnetization easy axis 300 of the first portion 250 is more parallel to the d-axis than the direction of the magnetization easy axis 310 of the second portion 260. In other words, the magnet unit 42 is configured such that the angle θ 11 between the easy axis 300 of the first portion 250 and the d-axis is smaller than the angle θ 12 between the easy axis 310 of the second portion 260 and the q-axis.

In more detail, the angle θ 11 is an angle formed by the d-axis and the magnetization easy axis 300 when the direction from the stator 50 (armature) toward the magnet unit 42 on the d-axis is set to be positive. The angle θ 12 is an angle formed by the q-axis and the magnetization easy axis 310 when the direction from the stator 50 (armature) toward the magnet unit 42 on the q-axis is set to be positive. In the present embodiment, both the angle θ 11 and the angle θ 12 are 90 ° or less. The easy axes 300 and 310 are defined as follows. In each of the portions of the magnets 91 and 92, when one easy axis is oriented in the direction a11 and the other easy axis is oriented in the direction B11, the absolute value (| cos θ |) of the cosine of the angle θ formed by the direction a11 and the direction B11 is defined as the easy axis 300 or the easy axis 310.

That is, the directions of the magnetization easy axes of the magnets 91 and 92 are different between the d-axis side (portion close to the d-axis) and the q-axis side (portion close to the q-axis), and the direction of the magnetization easy axis is a direction close to a direction parallel to the d-axis on the d-axis side and a direction close to a direction orthogonal to the q-axis on the q-axis side. Further, a magnetic path of the magnet is formed in a circular arc shape in accordance with the direction of the easy magnetization axis. In the magnets 91 and 92, the easy magnetization axis may be parallel to the d-axis on the d-axis side and may be perpendicular to the q-axis on the q-axis side.

In the magnets 91 and 92, the outer surface of the circumferential surface of each magnet 91 and 92 on the stator 50 side (lower side in fig. 9) and the end surface on the q-axis side in the circumferential direction are flux acting surfaces that are inflow and outflow surfaces of magnetic flux, and the magnet magnetic path is formed so as to connect the flux acting surfaces (the outer surface on the stator side and the end surface on the q-axis side).

In the magnet unit 42, the magnetic flux flows in an arc shape between the adjacent N pole and S pole by the magnets 91 and 92, and thus the magnet magnetic path is longer than that of, for example, a radial anisotropic magnet. Therefore, as shown in fig. 17, the magnetic flux density distribution approaches a sine wave. As a result, unlike the magnetic flux density distribution of the radial anisotropic magnet shown as a comparative example in fig. 18, the magnetic flux can be concentrated on the center side of the magnetic pole, and the torque of the rotating electrical machine 10 can be increased. In addition, in the magnet unit 42 of the present embodiment, it was confirmed that there was a difference in magnetic flux density distribution as compared with the magnet of the conventional halbach array. In fig. 17 and 18, the horizontal axis represents the electrical angle, and the vertical axis represents the magnetic flux density. In fig. 17 and 18, 90 ° on the horizontal axis represents the d axis (i.e., the magnetic pole center), and 0 ° and 180 ° on the horizontal axis represent the q axis.

That is, according to the magnets 91 and 92 configured as described above, the magnet magnetic flux in the d axis is enhanced, and the magnetic flux change in the vicinity of the q axis is suppressed. This makes it possible to realize magnets 91 and 92 with a reduced surface magnetic flux change from the q-axis to the d-axis in each magnetic pole.

The sine wave matching rate of the magnetic flux density distribution is preferably 40% or more, for example. Thus, the magnetic flux at the center of the waveform can be reliably increased as compared with the case of using a radially oriented magnet having a sine wave matching rate of about 30% or using a parallel oriented magnet. Further, when the sine wave matching rate is 60% or more, the magnetic flux at the center of the waveform can be reliably increased as compared with a flux concentration array such as a halbach array.

In the radial anisotropic magnet shown in fig. 18, the magnetic flux density sharply changes in the vicinity of the q-axis. The more rapid the change in the magnetic flux density, the more the eddy current generated in the stator winding 51 increases. Further, the magnetic flux change on the stator winding 51 side also becomes abrupt. In contrast, in the present embodiment, the magnetic flux density distribution has a waveform close to a sine wave. Therefore, the variation in magnetic flux density is smaller in the vicinity of the q-axis than in the radial anisotropic magnet. This can suppress the generation of eddy current.

In the magnet unit 42, magnetic flux is generated in the vicinity of the d axis (i.e., the magnetic pole center) of each of the magnets 91 and 92 in a direction perpendicular to the magnetic flux acting surface 280 on the stator 50 side, and the magnetic flux is formed in an arc shape such that the magnetic flux acting surface 280 on the stator 50 side is further from the d axis. The more the magnetic flux is perpendicular to the magnetic flux action surface, the stronger the magnetic flux. In this regard, in the rotary electric machine 10 of the present embodiment, since each of the lead wire groups 81 is thinned in the radial direction as described above, the center position in the radial direction of the lead wire group 81 is close to the magnetic flux acting surface of the magnet unit 42, and a strong magnet magnetic flux can be received from the rotor 40 in the stator 50.

Further, a cylindrical stator core 52 is provided on the radially inner side of the stator winding 51 of the stator 50, i.e., on the opposite side of the rotor 40 with the stator winding 51 therebetween. Therefore, while the stator core 52 is used as a part of the magnetic circuit, the magnetic flux extending from the magnetic flux acting surface of each of the magnets 91, 92 is attracted by the stator core 52 and surrounds the stator core 52 in a single turn. In this case, the direction and path of the magnetic flux of the magnet can be optimized.

Hereinafter, as a method of manufacturing the rotating electric machine 10, an assembly sequence of the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 shown in fig. 5 will be described. As shown in fig. 6, the inverter unit 60 includes a unit base 61 and an electric component 62, and respective working steps including an assembling step of the unit base 61 and the electric component 62 will be described. In the following description, an assembly constituted by the stator 50 and the inverter unit 60 is referred to as a first unit, and an assembly constituted by the bearing unit 20, the housing 30, and the rotor 40 is referred to as a second unit.

The manufacturing process comprises:

a first step of attaching the electrical component 62 to the inside of the unit base 61 in the radial direction;

a second step of attaching the unit base 61 to the inside of the stator 50 in the radial direction to fabricate a first unit;

a third step of inserting the fixing portion 44 of the rotor 40 into the bearing unit 20 assembled to the housing 30 to manufacture a second unit;

a fourth step of attaching the first unit to the inside of the second unit in the radial direction; and

a fifth step of fastening and fixing the housing 30 and the unit base 61.

The above steps are performed in the order of first step → second step → third step → fourth step → fifth step.

According to the above manufacturing method, since the bearing unit 20, the housing 30, the rotor 40, the stator 50, and the inverter unit 60 are assembled into a plurality of assemblies (subassemblies) and then the assemblies are assembled with each other, easy transportation, completion of inspection of each unit, and the like can be achieved, and a rational assembly line can be constructed. Therefore, it is possible to easily cope with production of various varieties.

In the first step, it is preferable that a heat conductor having good heat conduction is attached to at least one of the radially inner side of the unit base 61 and the radially outer side of the electric component 62 by coating, bonding, or the like, and the electric component 62 is attached to the unit base 61 in this state. This enables the heat generated by the semiconductor module 66 to be efficiently transferred to the unit base 61.

In the third step, the insertion operation of the rotor 40 is preferably performed while maintaining the coaxial relationship between the housing 30 and the rotor 40. Specifically, for example, a jig for determining the position of the outer peripheral surface of the rotor 40 (the outer peripheral surface of the magnet holder 41) or the inner peripheral surface of the rotor 40 (the inner peripheral surface of the magnet unit 42) with respect to the inner peripheral surface of the housing 30 is used, and the housing 30 and the rotor 40 are assembled while sliding either one of the housing 30 and the rotor 40 along the jig. This allows the weight member to be assembled without applying an unbalanced load to the bearing unit 20, thereby improving the reliability of the bearing unit 20.

In the fourth step, it is preferable that the first unit and the second unit are assembled while maintaining the same axis. Specifically, for example, a jig for determining the position of the inner peripheral surface of the unit base 61 with respect to the inner peripheral surface of the fixing portion 44 of the rotor 40 is used, and the first unit and the second unit are assembled while sliding one of the units along the jig. Accordingly, since the rotor 40 and the stator 50 can be assembled while preventing interference between the extremely small gaps, it is possible to eliminate damage to the stator winding 51 and defective products due to assembly such as a notch of the permanent magnet.

The order of the steps may be set to second step → third step → fourth step → fifth step → first step. In this case, the stress applied to the electrical component 62 in the assembly process can be minimized by finally assembling the precision electrical component 62.

Next, the configuration of a control system for controlling the rotating electric machine 10 will be described. Fig. 19 is a circuit diagram of a control system of the rotating electric machine 10, and fig. 20 is a functional block diagram showing a control process of the control device 110.

In fig. 19, two sets of three- phase windings 51a and 51b are shown as the stator winding 51, the three-phase winding 51a being configured by a U-phase winding, a V-phase winding, and a W-phase winding, and the three-phase winding 51b being configured by an X-phase winding, a Y-phase winding, and a Z-phase winding. A first inverter 101 and a second inverter 102 corresponding to power converters are provided for the three- phase windings 51a and 51b, respectively. The inverters 101 and 102 are constituted by a full bridge circuit having upper and lower arms, the number of which is the same as the number of phases of the phase windings, and the conduction current in each phase winding of the stator winding 51 is adjusted by turning on and off a switch (semiconductor switching element) provided in each arm.

A dc power supply 103 and a smoothing capacitor 104 are connected in parallel to the inverters 101 and 102. The dc power supply 103 is formed of, for example, a battery pack in which a plurality of cells are connected in series. The switches of the inverters 101 and 102 correspond to the semiconductor module 66 shown in fig. 1 and the like, and the capacitor 104 corresponds to the capacitor module 68 shown in fig. 1 and the like.

The control device 110 includes a microcomputer having a CPU and various memories, and performs energization control by turning on and off the switches of the inverters 101 and 102 based on various kinds of detection information in the rotating electric machine 10 and requests for power running drive and power generation. The control device 110 corresponds to the control device 77 shown in fig. 6. The detection information of the rotating electrical machine 10 includes: for example, the rotation angle (electrical angle information) of the rotor 40 detected by an angle detector such as a resolver, the power supply voltage (inverter input voltage) detected by a voltage sensor, and the conduction current of each phase detected by a current sensor. The control device 110 generates and outputs operation signals for operating the switches of the inverters 101 and 102. In addition, when the rotating electrical machine 10 is used as a power source for a vehicle, for example, the request for power generation is a request for regenerative drive.

The first inverter 101 includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in each of three phases including a U phase, a V phase, and a W phase. The high-potential-side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the dc power supply 103, and the low-potential-side terminal of the lower arm switch Sn of each phase is connected to the negative terminal of the dc power supply 103 (grounded). One ends of the U-phase winding, the V-phase winding, and the W-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. The above-mentioned phase windings are star-connected (Y-connected), and the other ends of the phase windings are connected to each other at a neutral point.

The second inverter 102 has the same configuration as the first inverter 101, and includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in each of three phases including an X phase, a Y phase, and a Z phase. The high-potential-side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the dc power supply 103, and the low-potential-side terminal of the lower arm switch Sn of each phase is connected to the negative terminal of the dc power supply 103 (grounded). One ends of an X-phase winding, a Y-phase winding, and a Z-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. The above-described phase windings are star-connected (Y-connected), and the other ends of the phase windings are connected to each other at a neutral point.

Fig. 20 shows a current feedback control process of controlling the respective phase currents of the U-phase, V-phase, and W-phase, and a current feedback control process of controlling the respective phase currents of the X-phase, Y-phase, and Z-phase. First, the control processing on the U-phase, V-phase, and W-phase sides will be described.

In fig. 20, the current command value setting unit 111 sets the d-axis current command value and the q-axis current command value based on the electrical angular velocity ω obtained by time-differentiating the electrical angle θ with respect to the motoring torque command value or the generating torque command value of the rotating electrical machine 10 using the torque-dq map. The current command value setting unit 111 is provided in common on the U-phase, V-phase, and W-phase sides and on the X-phase, Y-phase, and Z-phase sides. In addition, for example, when the rotating electrical machine 10 is used as a power source for a vehicle, the generated torque command value is a regenerative torque command value.

The dq conversion unit 112 converts current detection values (three phase currents) detected by current sensors provided for the respective phases into d-axis current and q-axis current, which are components of an orthogonal two-dimensional rotating coordinate system having an excitation direction (or field direction) as the d-axis.

The d-axis current feedback control unit 113 calculates a command voltage of the d-axis as an operation amount for feedback-controlling the d-axis current to a current command value of the d-axis. Further, the q-axis current feedback control section 114 calculates a command voltage of the q-axis as an operation amount for feedback-controlling the q-axis current to a current command value of the q-axis. In the feedback control units 113 and 114, the command voltage is calculated by using the PI feedback method based on the deviation between the d-axis current and the q-axis current from the current command value.

The three-phase converter 115 converts the command voltages for the d-axis and q-axis into command voltages for the U-phase, V-phase, and W-phase. The units 111 to 115 are feedback control units for performing feedback control of the fundamental wave current based on the dq conversion theory, and the command voltages for the U-phase, V-phase, and W-phase are feedback control values.

Then, the operation signal generation unit 116 generates operation signals of the first inverter 101 based on the three-phase command voltages by a well-known triangular wave carrier comparison method. Specifically, the operation signal generation unit 116 generates switching operation signals (duty signals) of the upper and lower arms of each phase by PWM control based on comparison of the magnitude of a signal obtained by normalizing the three-phase command voltage with the power supply voltage and a carrier signal such as a triangular wave signal.

The same configuration is also applied to the X-phase, Y-phase, and Z-phase sides, and the dq converter 122 converts current detection values (three phase currents) detected by current sensors provided for the respective phases into d-axis currents and q-axis currents, which are components of an orthogonal two-dimensional rotating coordinate system having the excitation direction as the d-axis.

The d-axis current feedback control unit 123 calculates a command voltage for the d-axis, and the q-axis current feedback control unit 124 calculates a command voltage for the q-axis. The three-phase converter 125 converts the d-axis and q-axis command voltages into X-phase, Y-phase, and Z-phase command voltages. Then, the operation signal generation section 126 generates operation signals of the second inverter 102 based on the three-phase command voltages. Specifically, the operation signal generation unit 126 generates switching operation signals (duty signals) for the upper and lower arms of each phase by PWM control based on comparison of the magnitude of a signal obtained by normalizing the three-phase command voltage with the power supply voltage and a carrier signal such as a triangular wave signal.

The driver 117 turns on and off the switches Sp and Sn of the three phases in the inverters 101 and 102 based on the switching operation signals generated by the operation signal generation units 116 and 126.

Next, the torque feedback control process will be described. Under operating conditions where the output voltage of each inverter 101, 102 increases, such as a high rotation region and a high output region, the above-described processing is mainly used for the purpose of increasing the output of the rotating electrical machine 10 and reducing the loss. The control device 110 selects and executes one of the torque feedback control process and the current feedback control process based on the operating conditions of the rotating electric machine 10.

Fig. 21 shows torque feedback control processing corresponding to U-phase, V-phase, and W, and torque feedback control processing corresponding to X-phase, Y-phase, and Z. In fig. 21, the same components as those in fig. 20 are denoted by the same reference numerals, and description thereof is omitted. First, the control processing on the U-phase, V-phase, and W-phase sides will be described.

The voltage amplitude calculation unit 127 calculates a voltage amplitude command, which is a command value of the magnitude of the voltage vector, based on the power running torque command value or the power generation torque command value of the rotating electrical machine 10 and the electrical angular velocity ω obtained by time-differentiating the electrical angle θ.

The torque estimating unit 128a calculates torque estimated values corresponding to the U-phase, the V-phase, and the W-phase based on the d-axis current and the q-axis current converted by the dq converting unit 112. The torque estimating unit 128a may calculate the voltage amplitude command based on map information that sets the relationship between the d-axis current, the q-axis current, and the voltage amplitude command.

The torque feedback control unit 129a calculates a voltage phase command, which is a command value of the phase of the voltage vector, as an operation amount for feedback-controlling the torque estimation value to the power running torque command value or the power generation torque command value. In the torque feedback control portion 129a, the voltage phase command is calculated by using the PI feedback method based on the deviation of the torque estimated value from the power running torque command value or the power generation torque command value.

The operation signal generation unit 130a generates an operation signal of the first inverter 101 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generating unit 130a calculates command voltages for three phases based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and generates switching operation signals for the upper and lower arms in each phase by PWM control based on comparison of the magnitude of a signal obtained by normalizing the calculated command voltages for three phases with the power supply voltage and a carrier signal such as a triangular wave signal.

The operation signal generating unit 130a may generate the switching operation signal based on pulse pattern information, which is mapping information for setting the relationship between the voltage amplitude command, the voltage phase command, the electrical angle θ, and the switching operation signal, the voltage amplitude command, the voltage phase command, and the electrical angle θ.

The torque estimation unit 128b calculates torque estimation values corresponding to the X-phase, Y-phase, and Z-phase based on the d-axis current and the q-axis current converted by the dq conversion unit 122.

The torque feedback control portion 129b calculates a voltage phase command as an operation amount for feedback-controlling the torque estimation value to the power running torque command value or the power generation torque command value. In the torque feedback control portion 129b, the voltage phase command is calculated by using the PI feedback method based on the deviation of the torque estimated value from the power running torque command value or the power generation torque command value.

The operation signal generating unit 130b generates an operation signal of the second inverter 102 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generating unit 130b calculates command voltages for three phases based on the voltage amplitude command, the voltage phase command, and the electrical angle θ, and generates switching operation signals for the upper and lower arms in each phase by PWM control based on comparison of the magnitude of a signal obtained by normalizing the calculated command voltages for three phases with the power supply voltage and a carrier signal such as a triangular wave signal. The driver 117 turns on and off the switches Sp and Sn of the three phases in the inverters 101 and 102 based on the switching operation signals generated by the operation signal generation units 130a and 130 b.

The operation signal generating unit 130b may generate the switching operation signal based on pulse pattern information, which is mapping information for setting the relationship between the voltage amplitude command, the voltage phase command, the electrical angle θ, and the switching operation signal, the voltage amplitude command, the voltage phase command, and the electrical angle θ.

In the rotating electrical machine 10, there is a concern that galvanic corrosion of the bearings 21 and 22 may occur in association with generation of the shaft current. For example, when the energization of the stator winding 51 is switched by switching, distortion of magnetic flux occurs due to a slight deviation of switching timing (imbalance of switching), and thus there is a concern that galvanic corrosion may occur in the bearings 21 and 22 supporting the rotary shaft 11. The distortion of the magnetic flux is generated by the inductance of the stator 50, and the axial electromotive force generated by the distortion of the magnetic flux causes the insulation breakdown in the bearings 21 and 22, and the galvanic corrosion progresses.

In this regard, the following three countermeasures are taken as the galvanic corrosion countermeasures in the present embodiment. The first galvanic corrosion countermeasure is a galvanic corrosion suppression countermeasure: the coreless stator 50 reduces inductance and smoothes the magnetic flux of the magnet unit 42. The second electric corrosion countermeasure is an electric corrosion suppression countermeasure in which the rotating shaft is formed in a cantilever structure supported by the bearings 21 and 22. The third countermeasure against galvanic corrosion is a countermeasure against galvanic corrosion in which the annular stator winding 51 and the stator core 52 are molded together with a molding material. The above measures will be described in detail below.

First, according to the first countermeasure against electrolytic corrosion, in the stator 50, the non-pole teeth are provided between the respective lead groups 81 in the circumferential direction, and the seal member 57 made of a non-magnetic material is provided between the respective lead groups 81 in place of the pole teeth (iron cores) (see fig. 10). This can reduce the inductance of the stator 50. By reducing the inductance of the stator 50, even if the switching timing is varied when the stator winding 51 is energized, the occurrence of magnetic flux distortion due to the variation in the switching timing can be suppressed, and further, the electric corrosion of the bearings 21 and 22 can be suppressed. Further, the inductance of the d axis is preferably equal to or less than the inductance of the q axis.

In the magnets 91 and 92, the direction of the magnetization easy axis on the d-axis side is oriented more parallel to the d-axis than on the q-axis side (see fig. 9). This enhances the magnetic flux of the d-axis magnet, and smoothes the change in surface magnetic flux (increase and decrease in magnetic flux) from the q-axis to the d-axis in each magnetic pole. Therefore, a rapid voltage change due to switching unevenness can be suppressed, which contributes to suppressing galvanic corrosion.

According to the second countermeasure against electrolytic corrosion, the rotary electric machine 10 is arranged such that the bearings 21 and 22 are offset in one of the axial directions with respect to the axial center of the rotor 40 (see fig. 2). Thus, the influence of the electric corrosion can be reduced as compared with a structure in which a plurality of bearings are provided on both sides of the rotor in the axial direction. That is, in the structure in which the rotor is supported by the plurality of bearings in the double arm manner, a closed circuit is formed through the rotor, the stator, and the bearings (i.e., the bearings provided on both sides in the axial direction with the rotor interposed therebetween) in accordance with the generation of the high-frequency magnetic flux, and there is a concern that the electric corrosion of the bearings may occur due to the shaft current. In contrast, in the structure in which the rotor 40 is cantilever-supported by the plurality of bearings 21 and 22, the closed circuit is not formed, and the electric corrosion of the bearings is suppressed.

Further, regarding the structure for one-side arrangement of the bearings 21, 22, the rotary electric machine 10 has the following structure. In the magnet holder 41, a contact avoiding portion (see fig. 2) extending in the axial direction and avoiding contact with the stator 50 is provided in an intermediate portion 45 protruding in the radial direction of the rotor 40. In this case, when a closed circuit of the shaft current is formed via the magnet holder 41, the closed circuit length can be made longer to increase the circuit resistance thereof. This can suppress galvanic corrosion of the bearings 21 and 22.

The holding member 23 of the bearing unit 20 is fixed to the housing 30 on one side in the axial direction of the rotor 40, and the housing 30 and the unit base 61 (stator holder) are coupled to each other on the other side (see fig. 2). According to this configuration, it is possible to preferably realize a configuration in which the bearings 21 and 22 are disposed so as to be offset to one side in the axial direction of the rotary shaft 11 in the axial direction. Further, according to the present configuration, since the unit base 61 is connected to the rotary shaft 11 via the housing 30, the unit base 61 can be disposed at a position electrically separated from the rotary shaft 11. Further, when an insulating member such as resin is interposed between the unit base 61 and the housing 30, the unit base 61 and the rotary shaft 11 are further electrically separated from each other. This can appropriately suppress the galvanic corrosion of the bearings 21 and 22.

In the rotating electrical machine 10 of the present embodiment, the shaft voltage acting on the bearings 21 and 22 is reduced by the one-side arrangement of the bearings 21 and 22, for example. Further, the potential difference between the rotor 40 and the stator 50 decreases. Therefore, even if the conductive grease is not used for the bearings 21 and 22, the potential difference acting on the bearings 21 and 22 can be reduced. Since the conductive grease generally contains fine particles such as carbon, noise is considered to be generated. In this regard, in the present embodiment, non-conductive grease is used for the bearings 21 and 22. Therefore, the occurrence of noise in the bearings 21 and 22 can be suppressed. It is considered that noise countermeasure of the rotating electrical machine 10 is necessary when applied to an electric vehicle such as an electric vehicle, for example, and the above noise countermeasure can be preferably implemented.

According to the third countermeasure against galvanic corrosion, the stator winding 51 is molded together with the stator core 52 by using a molding material, thereby suppressing the positional deviation of the stator winding 51 in the stator 50 (refer to fig. 11). In particular, in the rotating electrical machine 10 of the present embodiment, since the inter-wire members (pole teeth) are not provided between the respective wire groups 81 in the circumferential direction of the stator winding 51, it is considered that a positional deviation may occur in the stator winding 51, but the positional deviation of the wires of the stator winding 51 is suppressed by molding the stator winding 51 together with the stator core 52. Therefore, it is possible to suppress the occurrence of magnetic flux distortion due to the positional deviation of the stator winding 51 and the occurrence of electric corrosion of the bearings 21 and 22 due to the magnetic flux distortion.

Further, since the unit base 61, which is a housing member for fixing the stator core 52, is formed of Carbon Fiber Reinforced Plastic (CFRP), discharge to the unit base 61 can be suppressed as compared with a case where it is formed of, for example, aluminum, and this is an ideal countermeasure against electric corrosion.

In addition, as a countermeasure against the galvanic corrosion of the bearings 21 and 22, at least one of the outer ring 25 and the inner ring 26 may be formed of a ceramic material, or an insulating sleeve or the like may be provided outside the outer ring 25.

Hereinafter, the other embodiments will be described mainly focusing on differences from the first embodiment.

(second embodiment)

In the present embodiment, the polar anisotropy structure of the magnet unit 42 in the rotor 40 is changed, and the following description is made in detail.

As shown in fig. 22 and 23, the magnet unit 42 is configured using a magnet array called a halbach array. That is, the magnet unit 42 has: the first magnets 131 whose magnetization direction (direction of magnetization vector) is the radial direction and the second magnets 132 whose magnetization direction (direction of magnetization vector) is the circumferential direction are arranged at predetermined intervals in the circumferential direction, and the second magnets 132 are arranged at positions between the first magnets 131 adjacent in the circumferential direction. The first magnet 131 and the second magnet 132 are permanent magnets made of rare earth magnets such as neodymium magnets.

The first magnets 131 are arranged so as to be circumferentially spaced apart from each other such that poles on the side (radially inner side) opposite to the stator 50 are alternately N poles and S poles. Further, the second magnets 132 are arranged with polarities alternating in the circumferential direction at positions adjacent to the respective first magnets 131. The cylindrical portion 43 surrounding the magnets 131 and 132 is preferably a soft magnetic core made of a soft magnetic material and functions as a support core. In addition, the relationship between the easy magnetization axis and the d-axis and the relationship between the easy magnetization axis and the q-axis in the d-q coordinate system of the magnet unit 42 of the second embodiment are the same as those of the first embodiment.

Further, a magnetic body 133 made of a soft magnetic material is disposed radially outward of the first magnetic body 131, i.e., on the cylindrical portion 43 side of the magnet holder 41. For example, the magnetic body 133 is preferably made of an electromagnetic steel plate, soft iron, or a dust core material. In this case, the circumferential length of the magnetic body 133 is the same as the circumferential length of the first magnet 131 (particularly, the circumferential length of the outer peripheral portion of the first magnet 131). The thickness of the integrated body in the radial direction in the state where the first magnet 131 and the magnetic body 133 are integrated is the same as the thickness of the second magnet 132 in the radial direction. In other words, the radial thickness of the first magnet 131 is thinner than the radial thickness of the second magnet 132 by the amount of the magnetic body 133. The magnets 131 and 132 and the magnetic body 133 are fixed to each other by, for example, an adhesive. The radially outer side of the first magnet 131 in the magnet unit 42 is the side opposite to the stator 50, and the magnetic body 133 is provided on the side opposite to the stator 50 (the opposite-stator side) of both sides of the first magnet 131 in the radial direction.

A key 134 is formed on the outer peripheral portion of the magnetic body 133, and the key 134 is a convex portion protruding radially outward, that is, toward the cylindrical portion 43 of the magnet holder 41. In addition, a key groove 135 is formed in the inner peripheral surface of the cylindrical portion 43, and the key groove 135 is a recess for receiving the key 134 of the magnetic body 133. The protruding shape of the key 134 is the same as the groove shape of the key groove 135, and the same number of key grooves 135 as the number of keys 134 are formed corresponding to the keys 134 formed on the respective magnetic bodies 133. The position deviation in the circumferential direction (rotational direction) of the first magnet 131 and the second magnet 132 and the magnet holder 41 is suppressed by the engagement of the key 134 and the key groove 135. In addition, the key 134 and the key groove 135 (convex portion and concave portion) may be provided in either one of the cylindrical portion 43 of the magnet holder 41 and the magnetic body 133, or the key groove 135 may be provided on the outer peripheral portion of the magnetic body 133 and the key 134 may be provided on the inner peripheral portion of the cylindrical portion 43 of the magnet holder 41, in contrast to the above.

Here, in the magnet unit 42, the magnetic flux density in the first magnet 131 can be increased by alternately arranging the first magnet 131 and the second magnet 132. Therefore, the magnet unit 42 can generate single-sided concentration of magnetic flux, and thus strengthen the magnetic flux on the side closer to the stator 50.

Further, by disposing the magnetic body 133 on the radially outer side of the first magnetic body 131, that is, on the opposite side of the stator, local magnetic saturation on the radially outer side of the first magnetic body 131 can be suppressed, and further, demagnetization of the first magnetic body 131 due to the magnetic saturation can be suppressed. Thereby, the magnetic force of the magnet unit 42 can be increased finally. In other words, the magnet unit 42 of the present embodiment is configured such that a portion of the first magnet 131, which is likely to be demagnetized, is replaced with the magnetic body 133.

Fig. 24 (a) and 24 (b) are diagrams specifically showing the flow of magnetic flux in the magnet unit 42, fig. 24 (a) shows a case where a conventional configuration having no magnetic body 133 in the magnet unit 42 is used, and fig. 24 (b) shows a case where the configuration of the present embodiment having the magnetic body 133 in the magnet unit 42 is used. In fig. 24 (a) and 24 (b), the cylindrical portion 43 of the magnet holder 41 and the magnet unit 42 are linearly developed, and the lower side of the drawing is the stator side and the upper side is the opposite side to the stator.

In the structure of fig. 24 (a), the magnetic flux acting surface of the first magnet 131 and the side surface of the second magnet 132 are in contact with the inner circumferential surface of the cylindrical portion 43, respectively. Further, the magnetic flux acting surface of the second magnet 132 is in contact with the side surface of the first magnet 131. In this case, a resultant magnetic flux of a magnetic flux F1 entering the contact surface with the first magnet 131 through the outer path of the second magnet 132 and a magnetic flux F2 that is substantially parallel to the cylindrical portion 43 and attracts the second magnet 132 is generated in the cylindrical portion 43. Therefore, there is a fear that local magnetic saturation occurs in the cylindrical portion 43 in the vicinity of the contact surface of the first magnet 131 and the second magnet 132.

In contrast, in the configuration of fig. 24 (b), since the magnetic body 133 is provided between the magnetic flux acting surface of the first magnet 131 and the inner circumferential surface of the cylindrical portion 43 on the side of the first magnet 131 opposite to the stator 50, the magnetic flux is allowed to pass through the magnetic body 133. Therefore, magnetic saturation in the cylindrical portion 43 can be suppressed, and the resistance to demagnetization can be improved.

In the configuration of fig. 24 (b), unlike fig. 24 (a), F2 that promotes magnetic saturation can be eliminated. This effectively improves the flux guide of the entire magnetic circuit. With the above configuration, the magnetic circuit characteristics can be maintained even under severe high temperature conditions.

Further, the magnetic path through the magnet inside the magnet is longer than the radial magnet in the conventional SPM rotor. Therefore, the magnetic permeability of the magnet can be increased, the magnetic force can be increased, and the torque can be increased. Further, the sine wave matching rate can be improved by concentrating the magnetic flux at the center of the d-axis. In particular, when the current waveform is changed to a sine wave or a trapezoidal wave by PWM control or when a switching IC for conducting current at 120 degrees is used, torque can be more effectively increased.

In addition, in the case where the stator core 52 is formed of electromagnetic steel plates, the radial thickness of the stator core 52 is preferably greater than or equal to 1/2, which is the radial thickness of the magnet unit 42. For example, the radial thickness of the stator core 52 is preferably greater than 1/2 of the radial thickness of the first magnet 131 provided at the center of the magnetic pole in the magnet unit 42. Further, the radial thickness of the stator core 52 is preferably smaller than the radial thickness of the magnet unit 42. In this case, since the magnet magnetic flux is about 1T and the saturation magnetic flux density of the stator core 52 is 2T, leakage of the magnetic flux to the inner peripheral side of the stator core 52 can be prevented by setting the radial thickness of the stator core 52 to 1/2 or more of the radial thickness of the magnet unit 42.

In the magnetic body having the halbach structure and the polar anisotropic structure, the magnetic path is substantially circular arc-shaped, and therefore the magnetic flux can be increased in proportion to the thickness of the magnetic body receiving the magnetic flux in the circumferential direction. In the above-described structure, it is considered that the magnetic flux flowing through the stator core 52 does not exceed the magnetic flux in the circumferential direction. That is, when an iron-based metal having a saturation magnetic flux density of 2T is used for the magnetic flux 1T of the magnet, it is possible to provide a small-sized and lightweight rotating electrical machine without causing magnetic saturation by setting the thickness of the stator core 52 to be at least half the thickness of the magnet. Here, since the counter magnetic field from the stator 50 acts on the magnet magnetic flux, the magnet magnetic flux is usually 0.9T or less. Therefore, if the stator core has a thickness half that of the magnet, the magnetic permeability can be desirably kept high.

A modified example in which a part of the above-described structure is changed will be described below.

(modification 1)

In the above embodiment, the outer peripheral surface of the stator core 52 is formed into a curved surface shape without unevenness, and a plurality of lead groups 81 are arranged in parallel on the outer peripheral surface at predetermined intervals. For example, as shown in fig. 25, the stator core 52 includes an annular yoke portion 141 provided on the side (lower side in the figure) opposite to the rotor 40 of both sides in the radial direction of the stator winding 51, and a protrusion portion 142 extending from the yoke portion 141 so as to protrude between the linear portions 83 adjacent in the circumferential direction. The protrusions 142 are provided at predetermined intervals on the rotor 40 side, which is the radially outer side of the yoke 141. Each of the lead wire groups 81 of the stator winding 51 is engaged with the protrusions 142 in the circumferential direction, and the protrusions 142 are arranged side by side in the circumferential direction while serving as positioning portions of the lead wire groups 81. The protrusion 142 corresponds to an "inter-wire member".

The protrusion 142 is configured such that a thickness dimension in the radial direction from the yoke 141, in other words, as shown in fig. 25, a distance W from an inner surface 320 of the linear portion 83 adjacent to the yoke 141 to a vertex of the protrusion 142 in the radial direction of the yoke 141 is smaller than 1/2 (H1 in the drawing) of the thickness dimension in the radial direction of the linear portion 83 adjacent to the yoke 141 in the radial direction among the plurality of layers of linear portions 83 inside and outside in the radial direction. In other words, it suffices if the range of three quarters of the dimension (thickness) T1 of the lead wire group 81 (conductive member) in the radial direction of the stator winding 51 (stator core 52) (twice the thickness of the lead wire 82, in other words, the shortest distance between the surface 320 of the lead wire group 81 in contact with the stator core 52 and the surface 330 of the lead wire group 81 facing the rotor 40) is occupied by the nonmagnetic member (seal member 57). Due to the thickness limitation of the projection 142, the projection 142 does not function as a pole tooth between the circumferentially adjacent lead groups 81 (i.e., the linear portions 83), and a magnetic path formed by the pole tooth cannot be formed. The protrusions 142 may not be provided for all of the lead groups 81 arranged in the circumferential direction, and the protrusions 142 may be provided between at least one pair of lead groups 81 adjacent in the circumferential direction. For example, the protrusions 142 are preferably provided at equal intervals in the circumferential direction for every predetermined number of conductor groups 81. The shape of the protrusion 142 may be any shape such as a rectangle or an arc.

Further, the one-layer linear portion 83 may be provided on the outer peripheral surface of the stator core 52. Therefore, in a broad sense, the radial thickness of the projection 142 from the yoke 141 may be smaller than 1/2, which is the radial thickness of the linear portion 83.

When an imaginary circle is assumed which passes through the center position in the radial direction of the linear portion 83 adjacent to the yoke portion 141 in the radial direction with the axial center of the rotating shaft 11 as the center, the protrusion 142 preferably has a shape which protrudes from the yoke portion 141 within the range of the imaginary circle, in other words, a shape which does not protrude outward in the radial direction of the imaginary circle (i.e., the rotor 40 side).

According to the above configuration, since the thickness dimension of the projection 142 in the radial direction is restricted and the projection does not function as a tooth between the straight portions 83 adjacent in the circumferential direction, the adjacent straight portions 83 can be pulled closer than in the case where a tooth is provided between the straight portions 83. This can increase the cross-sectional area of the conductor 82a, and reduce heat generation associated with the energization of the stator winding 51. In the above configuration, magnetic saturation can be eliminated by not providing pole teeth, and the current to be supplied to the stator winding 51 can be increased. In this case, it is possible to ideally cope with a case where the heat generation amount increases with an increase in the above-described energization current. In the stator winding 51, the turn portions 84 have interference avoiding portions that are offset in the radial direction to avoid interference with other turn portions 84, and therefore, different turn portions 84 can be arranged apart from each other in the radial direction. This can improve heat dissipation even in the bent portion 84. As a result, the heat radiation performance of the stator 50 can be optimized.

Note that, if the yoke portion 141 of the stator core 52 and the magnet unit 42 of the rotor 40 (i.e., the magnets 91 and 92) are separated by a predetermined distance or more, the radial thickness dimension of the protrusion 142 is not limited to H1 in fig. 25. Specifically, when the yoke 141 and the magnet unit 42 are separated by 2mm or more, the radial thickness of the projection 142 may be H1 or more in fig. 25. For example, when the radial thickness dimension of the linear portion 83 exceeds 2mm and the lead group 81 is composed of two layers of the leads 82 inside and outside in the radial direction, the protrusion 142 may be provided within a range up to the linear portion 83 not adjacent to the yoke portion 141, that is, a half position of the lead 82 of the second layer from the yoke portion 141. In this case, if the radial thickness dimension of the protrusion 142 does not exceed "H1 × 3/2", the above-described effect can be significantly obtained by increasing the conductor cross-sectional area in the lead group 81.

The stator core 52 may have the structure shown in fig. 26. In fig. 26, the seal member 57 is omitted, but the seal member 57 may be provided. In fig. 26, the magnet unit 42 and the stator core 52 are shown linearly expanded for convenience of explanation.

In the structure of fig. 26, the stator 50 has the protrusion 142 as an inter-wire member between the circumferentially adjacent wires 82 (i.e., the straight portions 83). The stator 50 has a portion 350, the portion 350 magnetically acts together with one of the magnetic poles (N pole or S pole) of the magnet unit 42 when the stator winding 51 is energized, and the portion 350 extends in the circumferential direction of the stator 50. When the length of the portion 350 in the circumferential direction of the stator 50 is Wn, the total width of the protrusions 142 existing in the length range Wn (i.e., the total dimension in the circumferential direction of the stator 50) is Wt, the saturation magnetic flux density of the protrusions 142 is Bs, the width of the magnet unit 42 in the circumferential direction corresponding to one pole is Wm, and the residual magnetic flux density of the magnet unit 42 is Br, the protrusions 142 are made of a magnetic material satisfying the following equation.

Wt×Bs≤Wm×Br…(1)

In addition, the range Wn is set to include a plurality of conductor groups 81 adjacent in the circumferential direction and overlapping in excitation time. In this case, it is preferable to set the center of the gap 56 of the lead group 81 as a reference (boundary) in the setting range Wn. For example, in the case of the configuration illustrated in fig. 26, the plurality of lead groups 81 are arranged in order from the lead group 81 having the shortest distance from the center of the magnetic pole of the N-pole to the lead group 81 having the fourth shortest distance in the circumferential direction. The range Wn is set to include the four lead groups 81. At this time, the end (starting point and end point) of the range Wn is the center of the gap 56.

In fig. 26, half of the projection 142 is included at both ends of the range Wn, and therefore the range Wn includes four projection 142 in total. Therefore, when the width of the projection 142 (i.e., the size of the projection 142 in the circumferential direction of the stator 50, in other words, the interval between adjacent lead groups 81) is a, the total width of the projections 142 included in the range Wn is 1/2A + 1/2A-4A.

Specifically, in the present embodiment, the three-phase winding of the stator winding 51 is a distributed winding, and in the stator winding 51, the number of the protrusions 142, that is, the number of the gaps 56 between the respective conductor groups 81 is "number of phases × Q" for one pole of the magnet unit 42. Here, Q refers to the number of wires 82 of one phase that contact the stator core 52. In the case where the lead wire group 81 is configured such that the lead wires 82 are stacked in the radial direction of the rotor 40, Q may be the number of lead wires 82 on the inner peripheral side of the lead wire group 81 of one phase. In this case, when the three-phase windings of the stator winding 51 are energized in a predetermined order for each phase, the protrusions 142 corresponding to two phases are excited in one pole. Therefore, assuming that the circumferential width dimension of the projection 142 (i.e., the gap 56) is a, the total circumferential width dimension Wt of the projection 142 excited by energization of the stator winding 51 is "the number of excited phases × Q × a is 2 × 2 × a" in the range corresponding to one pole of the magnet unit 42.

Next, after the total width Wt is defined in this way, in the stator core 52, the protrusion 142 is made of a magnetic material satisfying the relationship (1) described above. The total width Wt is a circumferential dimension of a portion having a relative permeability greater than 1 in the one pole. In consideration of the margin, the total width Wt may be set to the circumferential width of the protrusion 142 of one magnetic pole. Specifically, since the number of the protrusions 142 corresponding to one pole of the magnet unit 42 is "phase number × Q", the circumferential width dimension (total width dimension Wt) of the protrusions 142 in one magnetic pole may be "phase number × Q × a — 3 × 2 × a — 6A".

The distributed winding referred to herein means that one pole pair of the stator winding 51 is present in one pole pair period (N pole and S pole) of the magnetic poles. A pole pair of the stator winding 51 described herein includes two straight portions 83 and a bent portion 84 in which currents flow in opposite directions to each other and are electrically connected at the bent portion 84. As long as the above condition is satisfied, even a Short Pitch Winding (Short Pitch Winding) is considered as an equivalent of a distributed Winding of a Full Pitch Winding (Full Pitch Winding).

Next, an example when the windings are concentrated is shown. The concentrated winding referred to herein means that the width of one pole pair of the magnetic poles is different from the width of one pole pair of the stator winding 51. As an example of the concentrated winding, the following relationship is given: the number of the magnetic pole pair wire groups 81 is 3 for one magnetic pole pair wire group 81, 3 for two magnetic pole pair wire groups 81, 9 for four magnetic pole pair wire groups 81, and 9 for five magnetic pole pair wire groups 81.

When the stator windings 51 are concentrated windings, the stator windings 51 corresponding to two phases are excited when three-phase windings of the stator windings 51 are energized in a predetermined order. As a result, the protrusions 142 corresponding to the two phases are excited. Therefore, in the range corresponding to one pole of the magnet unit 42, the width Wt in the circumferential direction of the protrusion 142 excited by energization of the stator winding 51 is "a × 2". Then, after the width Wt is defined in this way, the protrusion 142 is made of a magnetic material satisfying the relationship (1) above. In the case of the concentrated winding described above, a total sum of the widths of the protrusions 142 located in the circumferential direction of the stator 50 in the region surrounded by the lead groups 81 of the same phase is defined as a. In addition, Wm of the concentrated winding corresponds to "the entire circumference of the surface of the magnet unit 42 facing the air gap" x "the number of phases"/"the number of dispersions of the conductor group 81".

The BH product of neodymium magnet, samarium-cobalt magnet, and ferrite magnet is 20[ MGOe (kJ/m)³)]In the above magnet, Bd is 1.0[ T ]]Above, Br in iron is 2.0[ T ]]The above. Therefore, as a high-output motor, the protrusion 142 of the stator core 52 may be made of a magnetic material that satisfies the relationship Wt < 1/2 × Wm.

When the lead wires 82 include the outer layer film 182, as described later, the lead wires 82 may be arranged in the circumferential direction of the stator core 52 such that the outer layer films 182 of the lead wires 82 contact each other. In this case, Wt may be considered to be 0, or the thickness of the outer film 182 of the two conductive wires 82 in contact.

In the configuration of fig. 25 and 26, the inter-wire member (the protrusion 142) is configured to have a smaller magnetic flux than the magnet on the rotor 40 side. In addition, the rotor 40 is a surface magnet type rotor which is low in inductance and flat, and has no saliency in magnetic resistance. According to the above configuration, the inductance of the stator 50 can be reduced, the occurrence of magnetic flux distortion in the stator winding 51 due to variation in switching timing can be suppressed, and further, the galvanic corrosion of the bearings 21 and 22 can be suppressed.

(modification 2)

As the stator 50 using the member between the conductive wires satisfying the relationship of the above expression (1), the following configuration can be adopted. In fig. 27, a tooth 143 is provided as an inter-wire member on the outer circumferential surface side (upper surface side in the figure) of the stator core 52. The tooth-like portions 143 are provided to protrude from the yoke portion 141 at predetermined intervals in the circumferential direction and have the same thickness dimension as the lead group 81 in the radial direction. The side surfaces of the serrations 143 contact the respective leads 82 of the lead group 81. However, a gap may be provided between the serration 143 and each of the wires 82.

The tooth 143 is a member that imposes a limit on the width dimension in the circumferential direction and includes pole teeth (stator pole teeth) that are too thin with respect to the amount of magnet. With the above configuration, the teeth 143 can be magnetically saturated reliably by the magnetic flux of the magnet of 1.8T or more, and the inductance can be reduced by the reduction in the permeance.

Here, in the magnet unit 42, when the surface area of each pole of the magnetic flux acting surface on the stator side is Sm and the residual magnetic flux density of the magnet unit 42 is Br, the magnetic flux on the magnet unit side is, for example, "Sm × Br". When the rotor-side surface area of each tooth 143 is St, the number of phases of the lead wire 82 is m, and the teeth 143 corresponding to two phases in one pole are excited by the energization of the stator winding 51, the stator-side magnetic flux is, for example, "St × m × 2 × Bs". In this case, by passing

St×m×2×Bs＜Sm×Br…(2)

In a manner that the relation of (3) is established, the inductance is reduced by limiting the size of the serration 143.

When the axial dimensions of the magnet unit 42 and the tooth 143 are the same, the above equation (2) is replaced with equation (3) when the circumferential width of the magnet unit 42 corresponding to one pole is Wm and the circumferential width of the tooth 143 is Wst.

Wst×m×2×Bs＜Wm×Br…(3)

More specifically, when it is assumed that, for example, Bs is 2T, Br is 1T and m is 2, the above formula (3) is in the relationship "Wst < Wm/8". In this case, the reduction in inductance is achieved by 1/8 in which the width dimension Wst of the tooth 143 is made smaller than the width dimension Wm of the magnet unit 42 corresponding to one pole. If the number m is 1, the width Wst of the tooth 143 is preferably smaller than 1/4 of the width Wm of the magnet unit 42 corresponding to one pole.

In the above equation (3), "Wst × m × 2" corresponds to the circumferential width dimension of the tooth 143 excited by energization of the stator winding 51 in the range corresponding to one pole of the magnet unit 42.

In the configuration of fig. 27, similarly to the configurations of fig. 25 and 26 described above, the inter-wire member (the tooth-like portion 143) having a small magnetic flux with respect to the magnet on the rotor 40 side is provided. According to the above configuration, the inductance of the stator 50 can be reduced, the occurrence of magnetic flux distortion in the stator winding 51 due to variation in switching timing can be suppressed, and further, the galvanic corrosion of the bearings 21 and 22 can be suppressed.

(modification 3)

In the above embodiment, the seal member 57 covering the stator winding 51 is provided outside the stator core 52 in the radial direction in a range including all the lead groups 81, that is, in a range in which the thickness dimension in the radial direction is larger than the thickness dimension in the radial direction of each lead group 81. For example, as shown in fig. 28, the seal member 57 is configured such that a part of the lead 82 protrudes. More specifically, the seal member 57 is configured to expose a portion of the lead wire 82 closest to the radially outer side of the lead wire group 81 to the radially outer side, that is, the stator 50 side. In this case, the radial thickness dimension of the seal member 57 is preferably the same as or smaller than the radial thickness dimension of each lead group 81.

(modification 4)

As shown in fig. 29, in the stator 50, each lead group 81 may not be sealed by the sealing member 57. That is, the sealing member 57 covering the stator winding 51 is not used. In this case, no inter-wire member is provided between the respective wire groups 81 arranged in the circumferential direction, and a space is left. In short, no inter-wire member is provided between the respective wire groups 81 arranged in the circumferential direction. Further, air may be regarded as a nonmagnetic substance or an equivalent of a nonmagnetic substance as Bs 0, and air may be disposed in the gap.

(modification 5)

When the members between the wires of the stator 50 are made of a nonmagnetic material, a material other than resin may be used as the nonmagnetic material. For example, a metal-based nonmagnetic material such as SUS304, which is austenitic stainless steel, may be used.

(modification 6)

The stator 50 may not include the stator core 52. In this case, the stator 50 is constituted by a stator winding 51 shown in fig. 12. In the stator 50 not including the stator core 52, the stator winding 51 may be sealed by a sealing member. Alternatively, the stator 50 may include an annular winding holder made of a non-magnetic material such as synthetic resin, instead of the stator core 52 made of a soft magnetic material.

(modification 7)

In the first embodiment, the plurality of magnets 91 and 92 arranged in the circumferential direction are used as the magnet unit 42 of the rotor 40, but it is also possible to change this so that a ring-shaped magnet, which is an annular permanent magnet, is used as the magnet unit 42. Specifically, as shown in fig. 30, a ring-shaped magnet 95 is fixed to the inside in the radial direction of the cylindrical portion 43 of the magnet holder 41. The ring magnet 95 has a plurality of magnetic poles with alternating polarities in the circumferential direction, and a magnet is formed uniformly on either the d-axis or the q-axis. The annular magnet 95 has an arc-shaped magnet magnetic path, and the direction of the arc-shaped magnet magnetic path oriented along the d-axis of each magnetic pole is the radial direction, and the direction of the arc-shaped magnet magnetic path oriented along the q-axis between the magnetic poles is the circumferential direction.

In the ring-shaped magnet 95, the following arc-shaped magnet magnetic paths may be formed by orienting the magnet: the magnetization easy axis is a direction parallel to or close to parallel to the d axis in a portion close to the d axis, and the magnetization easy axis is a direction orthogonal to or close to orthogonal to the q axis in a portion close to the q axis.

(modification 8)

In the present modification, a part of the control method of the control device 110 is changed. In this modification, a description will be given mainly of a portion different from the configuration described in the first embodiment.

First, the processing in the operation signal generation units 116 and 126 shown in fig. 20 and the operation signal generation units 130a and 130b shown in fig. 21 will be described with reference to fig. 31. The processing in the operation signal generation units 116, 126, 130a, and 130b is basically the same. Therefore, the following description will be given taking the processing of the operation signal generation unit 116 as an example.

The operation signal generator 116 includes a carrier generator 116a and U and V comparators 116bU, 116bV, and 116W comparators 116 bW. In the present embodiment, the carrier generation unit 116a generates and outputs a triangular wave signal as the carrier signal SigC.

The U comparators 116bU, 116bV, and 116W comparators 116bW receive as input the carrier signal SigC generated by the carrier generation unit 116a and the U-phase, V-phase, and W-phase command voltages calculated by the three-phase conversion unit 115. The U-phase, V-phase, and W-phase command voltages are, for example, sine-wave-shaped waveforms, and are shifted in phase by every 120 ° in electrical angle.

The U comparators 116bU, 116bV, and 116W comparators 116bW generate operation signals of the switches Sp and Sn of the upper arm and the lower arm of the U-phase, V-phase, and W-phase in the first inverter 101 by PWM (pulse width modulation) control based on magnitude comparison of the U-phase, V-phase, and W-phase command voltages and the carrier signal SigC. Specifically, the operation signal generation unit 116 generates operation signals for the respective switches Sp and Sn of the U-phase, V-phase, and W-phase by PWM control based on comparison between the magnitude of the carrier signal and a signal obtained by normalizing the U-phase, V-phase, and W-phase command voltages by the power supply voltage. The driver 117 turns on and off the switches Sp and Sn of the U-phase, V-phase, and W-phase in the first inverter 101 based on the operation signal generated by the operation signal generating unit 116.

The control device 110 performs a process of changing the carrier frequency fc of the carrier signal SigC, that is, the switching frequency of each of the switches Sp, Sn. The carrier frequency fc is set higher in a low torque region or a high rotation region of the rotary electric machine 10, and is set lower in a high torque region of the rotary electric machine 10. The above setting is performed to suppress a decrease in controllability of the current flowing through each phase winding.

That is, the inductance of the stator 50 can be reduced as the stator 50 is coreless. Here, as the inductance becomes lower, the electrical time constant of the rotating electrical machine 10 becomes smaller. As a result, the ripple of the current flowing through the windings of each phase increases, and the controllability of the current flowing through the windings deteriorates, and there is a fear that the current control may diverge. The influence of the above-described decrease in controllability when included in the low current region is more significant than when the current flowing through the winding (for example, the actual effective value of the current) is included in the high current region. In order to solve the above problem, in the present modification, the control device 110 changes the carrier frequency fc.

The process of changing the carrier frequency fc will be described with reference to fig. 32. The above-described processing is repeatedly executed by the control device 110 as processing of the operation signal generation unit 116, for example, at a predetermined control cycle.

In step S10, it is determined whether or not the current flowing through the winding 51a of each phase is included in the low current region. The above processing is processing for determining that the current torque of the rotating electric machine 10 is in the low torque region. For example, the following first and second methods are cited as methods for determining whether or not the current is included in the low current region.

< first method >

The torque estimation value of the rotating electric machine 10 is calculated based on the d-axis current and the q-axis current converted by the dq conversion unit 112. Then, when it is determined that the calculated torque estimated value is lower than the torque threshold value, it is determined that the current flowing through the winding 51a is included in the low current region, and when it is determined that the torque estimated value is equal to or higher than the torque threshold value, it is determined that the current is included in the high current region. Here, the torque threshold value may be set to 1/2 of the starting torque (also referred to as locked-rotor torque) of the rotating electrical machine 10, for example.

< second method >

When it is determined that the rotation angle of the rotor 40 detected by the angle detector is equal to or greater than the speed threshold, it is determined that the current flowing through the winding 51a is included in the low current region, i.e., the high rotation region. Here, the speed threshold may be set to, for example, the rotation speed at which the maximum torque of the rotating electrical machine 10 is the torque threshold.

When a negative determination is made in step S10, it is determined to be in the high current region, and the process proceeds to step S11. In step S11, the carrier frequency fc is set to the first frequency fL.

When an affirmative determination is made in step S10, the process proceeds to step S12, and the carrier frequency fc is set to the second frequency fH that is higher than the first frequency fL.

According to the present modification described above, carrier frequency fc when the current flowing through each phase winding is included in the low current region is set higher than when the current flowing through each phase winding is included in the high current region. Therefore, in the low current region, the switching frequency of the switches Sp and Sn can be increased, and an increase in current ripple can be suppressed. This can suppress a decrease in current controllability.

On the other hand, carrier frequency fc is set lower when the current flowing through each phase winding is included in the high current region than when the current flowing through each phase winding is included in the low current region. In the high current region, since the amplitude of the current flowing through the winding is larger than that in the low current region, the influence of the increase in the current ripple caused by the inductance becoming lower on the current controllability is small. Therefore, carrier frequency fc in the high current region can be set lower than that in the low current region, and switching loss of each inverter 101, 102 can be reduced.

In this modification, the following modes can be implemented.

When the carrier frequency fc is set to the first frequency fL and an affirmative determination is made in step S10 of fig. 32, the carrier frequency fc may be gradually changed from the first frequency fL to the second frequency fH.

Further, in the case where the carrier frequency fc is set to the second frequency fH, the carrier frequency fc may be gradually changed from the second frequency fH to the first frequency fL when a negative determination is made in step S10.

Instead of PWM control, the operation signal of the switch may also be generated by Space Vector Modulation (SVM) control. In this case, the above-described change of the switching frequency can also be applied.

(modification 9)

In each of the above embodiments, as shown in fig. 33 (a), two pairs of wires for each phase constituting the wire group 81 are connected in parallel. Fig. 33 (a) is a diagram showing electrical connection between two pairs of conductive wires, i.e., a first conductive wire 88a and a second conductive wire 88 b. Here, instead of the configuration shown in fig. 33 (a), the first lead 88a and the second lead 88b may be connected in series as shown in fig. 33 (b).

Three or more pairs of multilayer conductors may be stacked and arranged in the radial direction. Fig. 34 shows a structure in which four pairs of conductive lines, i.e., first conductive line 88a to fourth conductive line 88d, are arranged in layers. The first to fourth lead wires 88a to 88d are arranged in order of the first to fourth lead wires 88a, 88b, 88c, 88d in the radial direction from the side close to the stator core 52.

Here, as shown in fig. 33 (c), the third lead wire 88c and the fourth lead wire 88d may be connected in parallel, and the first lead wire 88a may be connected to one end of the parallel connection body and the second lead wire 88b may be connected to the other end. When the wires are connected in parallel, the current density of the wires connected in parallel can be reduced, and heat generation during energization can be suppressed. Therefore, in the configuration in which the cylindrical stator winding is assembled to the housing (unit base 61) in which the cooling water passage 74 is formed, the first lead wire 88a and the second lead wire 88b, which are not connected in parallel, are disposed on the stator core 52 side in contact with the unit base 61, and the third lead wire 88c and the fourth lead wire 88d, which are connected in parallel, are disposed on the opposite side of the stator core. This can equalize the cooling performance of the leads 88a to 88d in the multilayer lead structure.

The radial thickness of the lead group 81 including the first to fourth leads 88a to 88d may be smaller than the circumferential width of one magnetic pole corresponding to one magnetic pole.

(modification 10)

The rotary electric machine 10 may have an inner rotor structure (inner rotor structure). In this case, for example, in the housing 30, it is preferable that a stator 50 is provided on the radially outer side and a rotor 40 is provided on the radially inner side of the stator 50. Further, the inverter unit 60 is preferably provided on one or both of the axial ends of the stator 50 and the rotor 40. Fig. 35 is a cross-sectional view of the rotor 40 and the stator 50, and fig. 36 is an enlarged view of a part of the rotor 40 and the stator 50 shown in fig. 35.

The structures of fig. 35 and 36, which are premised on the inner rotor structure, are the same as those of fig. 8 and 9, which are premised on the outer rotor structure, except that the rotor 40 and the stator 50 are diametrically opposed to each other. In short, the stator 50 has a stator winding 51 of a flat wire structure and a stator core 52 having no pole teeth. The stator winding 51 is assembled to the radially inner side of the stator core 52. The stator core 52 has any of the following configurations, as in the case of the outer rotor configuration.

(A) In the stator 50, an inter-wire member is provided between each of the circumferential wire portions, and as the inter-wire member, a magnetic material satisfying a relationship of Wt × Bs ≦ Wm × Br is used, where Wt is a circumferential width of the inter-wire member of one magnetic pole, Bs is a saturation magnetic flux density of the inter-wire member, Wm is a circumferential width of the magnet unit of one magnetic pole, and Br is a residual magnetic flux density of the magnet unit.

(B) In the stator 50, an inter-wire member is provided between the respective wire portions in the circumferential direction, and a non-magnetic material is used as the inter-wire member.

(C) The stator 50 is configured such that no inter-wire member is provided between the respective circumferential wire portions.

The magnets 91 and 92 of the magnet unit 42 are also the same. That is, the magnet unit 42 is configured by using the magnets 91 and 92, and the direction of the magnetization easy axis is oriented more parallel to the d axis on the d axis side, which is the magnetic pole center, than on the q axis side, which is the magnetic pole boundary. The details of the magnetization direction and the like of each magnet 91, 92 are as described above. A ring magnet 95 (see fig. 30) can also be used in the magnet unit 42.

Fig. 37 is a vertical sectional view of the rotary electric machine 10 in the case of the inner rotor type, and corresponds to fig. 2. The difference from the configuration of fig. 2 will be briefly described. In fig. 37, a ring-shaped stator 50 is fixed to the inside of the housing 30, and a rotor 40 is rotatably provided inside the stator 50 with a predetermined air gap therebetween. As in fig. 2, the bearings 21 and 22 are arranged offset to either one side in the axial direction with respect to the axial center of the rotor 40, thereby supporting the rotor 40 in a cantilever manner. Further, an inverter unit 60 is provided inside the magnet holder 41 of the rotor 40.

Fig. 38 shows the rotary electric machine 10 having another structure as the inner rotor structure. In fig. 38, a rotary shaft 11 is rotatably supported by a housing 30 via bearings 21 and 22, and a rotor 40 is fixed to the rotary shaft 11. As in the configuration shown in fig. 2 and the like, the bearings 21 and 22 are arranged offset in either axial direction with respect to the axial center of the rotor 40. The rotor 40 has a magnet holder 41 and a magnet unit 42.

In the rotating electrical machine 10 of fig. 38, as a difference from the rotating electrical machine 10 of fig. 37, the inverter unit 60 is not provided radially inside the rotor 40. The magnet holder 41 is coupled to the rotary shaft 11 at a position radially inward of the magnet unit 42. Further, the stator 50 has a stator winding 51 and a stator core 52, and is mounted to the housing 30.

(modification 11)

Hereinafter, another structure of the rotating electric machine as the inner rotor structure will be described. Fig. 39 is an exploded perspective view of rotary electric machine 200, and fig. 40 is a side sectional view of rotary electric machine 200. Here, the vertical direction is shown with reference to the state of fig. 39 and 40.

As shown in fig. 39 and 40, the rotating electric machine 200 includes: a stator 203 having a ring-shaped stator core 201 and a stator winding 202 of a plurality of phases; and a rotor 204 rotatably disposed inside stator core 201. The stator 203 corresponds to an armature, and the rotor 204 corresponds to a field element. The stator core 201 is formed by laminating a plurality of silicon steel plates, and the stator winding 202 is mounted on the stator core 201. Although illustration is omitted, the rotor 204 has a rotor core and a plurality of permanent magnets as magnet units. The rotor core is provided with a plurality of magnet insertion holes at equal intervals in the circumferential direction. Permanent magnets magnetized so that the magnetization direction changes alternately for each of the adjacent magnetic poles are respectively attached to the magnet insertion holes. In addition, the permanent magnets of the magnet unit preferably have a halbach array as illustrated in fig. 23 or a similar structure. Alternatively, the permanent magnet of the magnet unit preferably has a polar anisotropy characteristic in which the orientation direction (magnetization direction) extends in an arc shape between the d-axis, which is the magnetic pole center, and the q-axis, which is the magnetic pole boundary, as described with reference to fig. 9 and 30.

Here, the stator 203 is preferably configured as any one of the following.

(A) In the stator 203, an inter-wire member is provided between each of the circumferential wire portions, and as the inter-wire member, a magnetic material satisfying a relationship of Wt × Bs ≦ Wm × Br is used, where Wt is a circumferential width of the inter-wire member of one magnetic pole, Bs is a saturation magnetic flux density of the inter-wire member, Wm is a circumferential width of the magnet unit of one magnetic pole, and Br is a residual magnetic flux density of the magnet unit.

(B) In the stator 203, an inter-wire member is provided between the respective wire portions in the circumferential direction, and a non-magnetic material is used as the inter-wire member.

(C) The stator 203 is configured such that no inter-wire member is provided between the respective circumferential wire portions.

In the rotor 204, a plurality of magnets oriented such that the direction of the easy axis of magnetization is more parallel to the d axis at the magnetic pole center, i.e., the d axis side than the q axis side, which is the magnetic pole boundary, constitute a magnet unit.

An annular inverter case 211 is provided at one axial end of the rotating electric machine 200. The inverter case 211 is disposed such that the case lower surface is in contact with the upper surface of the stator core 201. Inside the inverter case 211 are provided: a plurality of power modules 212 constituting an inverter circuit; a smoothing capacitor 213 that suppresses ripples (ripples) of a voltage and a current generated by a switching operation of the semiconductor switching element; a control board 214 having a control section; a current sensor 215 that detects a phase current; and a rotational speed sensor of rotor 204, i.e., resolver stator 216. The power module 212 includes semiconductor switching elements, i.e., IGBTs and diodes.

The inverter case 211 has, at its peripheral edge: a power supply connector 217 connected to a dc circuit of a battery mounted on the vehicle; and a signal connector 218 for transmitting various signals between the rotating electrical machine 200 side and the vehicle side control device. The inverter case 211 is covered by a top cover 219. Dc power from the vehicle-mounted battery is input via the power connector 217, converted into ac by the switches of the power module 212, and transmitted to the stator winding 202 of each phase.

A bearing unit 221 that rotatably holds the rotary shaft of the rotor 204 and an annular rear case 222 that houses the bearing unit 221 are provided on the opposite side of the inverter case 211 from the axial direction both sides of the stator core 201. The bearing unit 221 includes, for example, a pair of two bearings, and is disposed so as to be offset to either one of the axial directions with respect to the axial center of the rotor 204. However, the plurality of bearings in the bearing unit 221 may be provided at both sides of the stator core 201 in the axial direction in a distributed manner, and the rotating shaft may be supported by the bearings in a double-arm manner. Rear case 222 is fixed to a mounting portion of a gear box, a transmission, or the like of the vehicle by fastening with a bolt, and rotating electric machine 200 is mounted on the vehicle side.

A cooling passage 211a through which a refrigerant flows is formed in the inverter case 211. The cooling passage 211a is formed by closing a space recessed annularly from the lower surface of the inverter case 211 by the upper surface of the stator core 201. The cooling passage 211a is formed to surround the coil side end of the stator winding 202. A module case 212a of the power module 212 is inserted into the cooling passage 211 a. The cooling flow path 222a is also formed in the rear case 222 so as to surround the coil side end of the stator winding 202. The cooling passage 222a is formed by closing a space annularly recessed from the upper surface of the rear case 222 by the lower surface of the stator core 201.

(modification 12)

Although the structure of the rotating electric machine embodied as a rotating field excitation type has been described above, the structure may be modified to embody a rotating armature type rotating electric machine. Fig. 41 shows a structure of a rotary armature type rotating electric machine 230.

In the rotating electric machine 230 of fig. 41, bearings 232 are fixed to the housings 231a and 231b, respectively, and a rotating shaft 233 is rotatably supported by the bearings 232. The bearing 232 is an oil-containing bearing in which oil is contained in, for example, a porous metal. A rotor 234 as an armature is fixed to the rotating shaft 233. The rotor 234 includes a rotor core 235 and a multiphase rotor winding 236 fixed to an outer peripheral portion of the rotor core 235. In the rotor 234, the rotor core 235 has a non-slotted structure, and the rotor winding 236 has a flat wire structure. That is, the rotor winding 236 is a flat structure in which the circumferential dimension of the region for one phase is larger than the radial dimension.

Further, a stator 237 as a field element is provided radially outside the rotor 234. The stator 237 includes: a stator core 238 fixed to the housing 231 a; and a magnet unit 239 fixed to an inner peripheral side of the stator core 238. The magnet unit 239 is configured to include a plurality of magnetic poles having polarities alternating in the circumferential direction, and is oriented such that the direction of the easy axis is more parallel to the d axis, which is the magnetic pole center, than the q axis, which is the magnetic pole boundary, similarly to the above-described magnet unit 42 and the like. The magnet unit 239 has an oriented sintered neodymium magnet, has an intrinsic coercive force of 400[ kA/m ] or more, and has a residual magnetic flux density of 1.0[ T ] or more.

The rotating electric machine 230 of this example is a two-pole three-coil coreless motor with brushes, the rotor winding 236 is divided into three, and the magnet unit 239 is two poles. The number of poles and coils of the brush-equipped motor is various, depending on the application, such as 2:3, 4:10, and 4: 21.

A commutator 241 is fixed to the rotating shaft 233, and a plurality of brushes 242 are arranged radially outward of the commutator 241. The rectifier 241 is electrically connected to the rotor winding 236 via a wire 243 embedded in the rotating shaft 233. The rectifier 241, the brush 242, and the lead 243 supply and discharge dc current to and from the rotor winding 236. The rectifier 241 is configured to be appropriately divided in the circumferential direction according to the number of phases of the rotor winding 236. The brush 242 may be connected directly to a dc power supply such as a battery via an electric wiring, or may be connected to the dc power supply via a terminal block or the like.

A resin washer 244 is provided as a sealing member between the bearing 232 and the commutator 241 on the rotary shaft 233. The resin washer 244 prevents oil that has leaked from the oil-retaining bearing, i.e., the bearing 232, from flowing out to the rectifier 241 side.

(modification 13)

In the stator winding 51 of the rotating electric machine 10, each of the lead wires 82 may have a structure having a plurality of insulating films inside and outside. For example, it is preferable that the lead wire 82 is formed by bundling a plurality of lead wires (wire rods) with an insulating film and covering the lead wires with an outer layer film. In this case, the insulating film of the wire rod constitutes an inner insulating film, and the outer layer film constitutes an outer insulating film. In particular, it is preferable that the insulating ability of the outer insulating film among the plurality of insulating films in the wire 82 is set higher than the insulating ability of the inner insulating film. Specifically, the thickness of the insulating film on the outer side is set to be larger than the thickness of the insulating film on the inner side. For example, the thickness of the outer insulating film is 100 μm, and the thickness of the inner insulating film is 40 μm. Alternatively, it is preferable to use a material having a lower dielectric constant than the inner insulating film as the outer insulating film. As long as at least any of the above can be applied. Further, the wire is preferably configured as an aggregate of a plurality of conductive members.

As described above, the present invention can be applied to a vehicle system for high voltage by enhancing the insulation of the outermost layer of the lead 82. The rotating electric machine 10 can be appropriately driven even in a plateau where the air pressure is low.

(modification 14)

In the lead 82 having a plurality of insulating films inside and outside, at least one of the linear expansion coefficient (linear expansion coefficient) and the adhesive strength may be different between the insulating film on the outside and the insulating film on the inside. Fig. 42 shows a structure of a lead wire 82 of the present modification.

In fig. 42, the lead 82 has: a plurality of strands (4 strands in the figure) of wire 181; an outer layer film 182 (outer insulating film) made of, for example, resin surrounding the plurality of strands of wires 181; and an intermediate layer 183 (intermediate insulating film) filling the outer layer film 182 around each wire 181. The wire 181 has a conductive portion 181a made of a copper material and a conductive film 181b (inner insulating film) made of an insulating material. In the case of a stator winding, the phases are insulated by the outer layer film 182. The wire 181 is preferably configured as an aggregate of a plurality of conductive members.

The intermediate layer 183 has a higher linear expansion rate than the conductive film 181b of the wire 181, and has a lower linear expansion rate than the outer layer film 182. That is, the linear expansion coefficient of the lead 82 is higher as it is closer to the outside. Normally, the outer layer film 182 has a higher linear expansion coefficient than the conductive film 181b, but by providing the intermediate layer 183 having an intermediate linear expansion coefficient between the outer layer film 182 and the conductive film 181b, the intermediate layer 183 can function as a buffer member, and simultaneous cracking on the outer layer side and the inner layer side can be prevented.

In the lead 82, the conductive portion 181a and the conductive film 181b are bonded to each other in the wire 181, and the conductive film 181b and the intermediate layer 183, and the outer layer film 182 are bonded to each other, and the bonding strength is weaker in each of the bonded portions as the portion becomes closer to the outside of the lead 82. That is, the adhesion strength between the conductive portion 181a and the conductive film 181b is weaker than the adhesion strength between the conductive film 181b and the intermediate layer 183 and the adhesion strength between the intermediate layer 183 and the outer layer film 182. When the adhesion strength to the conductive film 181b and the intermediate layer 183 is compared with the adhesion strength to the intermediate layer 183 and the outer layer film 182, it is preferable that one of the latter (outer side) is weak or the same. The magnitude of the adhesive strength between the films can be determined by, for example, the tensile strength required when peeling the two films. By setting the bonding strength of the lead 82 as described above, even if a difference in internal and external temperatures occurs due to heat generation or cooling, it is possible to suppress occurrence of cracking (co-cracking) on both the inner layer side and the outer layer side.

Here, the heat generation and temperature change of the rotating electrical machine are mainly caused by the copper loss generated from the conductive portion 181a of the wire 181 and the iron loss generated from the inside of the core, but both of the losses are transmitted from the conductive portion 181a in the lead 82 or the outside of the lead 82, and the heat generation source is not in the intermediate layer 183. In this case, the intermediate layer 183 has an adhesive force that can be reduced in both directions, thereby preventing the simultaneous cracking. Therefore, the present invention can be suitably used even in the field of high withstand voltage or large temperature change such as vehicle use.

The following is supplementary. The wire 181 may be, for example, a porcelain enamel wire, and in this case, has a resin film layer (conductor film 181b) such as PA, PI, PAI, or the like. Further, the outer layer film 182 on the outer side of the wire 181 is preferably made of the same PA, PI, PAI, or the like, and is thick. Thus, the destruction of the film due to the difference in linear expansion coefficient is suppressed. In addition to the above-described materials such as PA, PI, and PAI, the outer layer film 182 is preferably made thicker by using a material having a lower dielectric constant than PI and PAI, such as PPS, PEEK, fluorine, polycarbonate, silicon, epoxy resin, polyethylene naphthalate, and LCP, in order to increase the conductor density of the rotating electric machine. The resin can improve the insulating ability even if it is thinner than PI or PAI films similar to the conductive film 181b or has the same thickness as the conductive film 181b, thereby improving the occupancy of the conductive portion. Generally, the above resin has better insulation of dielectric constant than the insulating film of the enamel wire. Of course, there are also cases where the dielectric constant is deteriorated due to the molding state or the mixture. Among them, PPS and PEEK are generally suitable as an outer layer film of the second layer because they have a linear expansion coefficient larger than that of the enamel film but smaller than that of other resins.

Further, the adhesion strength between the two films (the intermediate insulating film and the outer insulating film) on the outer side of the wire 181 and the enamel film of the wire 181 is preferably weaker than the adhesion strength between the copper wire and the enamel film in the wire 181. This suppresses the phenomenon that the enamel film and the above-described both films are once destroyed.

When a water cooling structure, a liquid cooling structure, or an air cooling structure is added to the stator, basically, it is considered that a thermal stress or an impact stress is applied from the outer layer film 182. However, even when the insulating layer of the wire 181 and the two films are made of different resins, the thermal stress and the impact stress can be reduced by providing a portion where the films are not bonded. That is, the insulating structure is completed by providing a gap with the wire (enamel wire) and disposing fluorine, polycarbonate, silicon, epoxy resin, polyethylene naphthalate, and LCP. In this case, it is preferable to bond the outer layer film and the inner layer film using an adhesive material having a low dielectric constant and a low linear expansion coefficient, such as an epoxy resin. Thus, not only can the mechanical strength be improved, but also the film failure due to friction caused by vibration or the like of the conductive portion or the failure of the outer layer film due to a difference in linear expansion coefficient can be suppressed.

As the outermost layer of the lead wire 82 having the above-described structure, which is generally used as a final step of winding the stator winding, and which is responsible for mechanical strength, fixation, and the like, it is preferable to use a resin having good moldability and properties close to those of an enamel film, such as epoxy resin, PPS, PEEK, and LCP.

The resin potting is generally performed using polyurethane or silicon, but the linear expansion coefficient of the resin is nearly twice as low as that of other resins, and thermal stress capable of shearing the resin is generated. Therefore, it is not suitable for use in applications of 60V or more, which are strictly used for insulation in the world. In this regard, the above-described respective requirements can be achieved by a final insulation process which is easily performed by injection molding or the like using an epoxy resin, PPS, PEEK, LCP, or the like.

Modifications other than the above are described below.

The distance DM in the radial direction between the surface of the magnet unit 42 on the armature side in the radial direction and the axial center of the rotor may be 50mm or more. Specifically, for example, the distance DM in the radial direction between the radially inner surface of the magnet unit 42 (specifically, the first magnet 91 and the second magnet 92) shown in fig. 4 and the axial center of the rotor 40 may be 50mm or more.

As a rotary electric machine having a non-slot structure, a small-sized rotary electric machine for a model or the like having an output of several tens W to several hundreds W is known. The present inventors have not found a case where a grooveless structure is adopted in an industrial large rotating electrical machine, such as a large rotating electrical machine of generally more than 10 kW. The inventors of the present application studied for the reason.

In recent years, the mainstream rotating electrical machines are roughly classified into the following four types. The rotating electric machine includes a brush motor, a cage induction motor, a permanent magnet synchronous motor, and a reluctance motor.

In the brush motor, a field current is supplied via a brush. Therefore, in the case of a brush motor of a large-sized device, the brush becomes large, and maintenance becomes complicated. With the remarkable development of semiconductor technology, brushless motors such as induction motors have been replaced. On the other hand, in the field of small motors, many coreless motors are also being supplied to the market from the viewpoint of low inertia and economical efficiency.

In a cage type induction motor, the principle is as follows: the torque is generated by receiving the magnetic field generated in the stator winding of the primary side with the iron core of the rotor of the secondary side to cause induced current to flow concentratedly toward the cage-type conductors to form a reaction magnetic field. Therefore, from the viewpoint of downsizing and high efficiency of the equipment, it is not necessarily a good measure to remove the iron core on both the stator side and the rotor side.

A reluctance motor is an electric motor that utilizes variation in the reluctance of an iron core, and elimination of the iron core is undesirable in principle.

In a permanent magnet synchronous motor, IPM (i.e., an embedded magnet rotor) has become the mainstream in recent years, and in particular, IPM is generally used in large-sized equipment unless otherwise specified.

The IPM has a characteristic of having both magnet torque and reluctance torque, and operates while adjusting the proportion of the above-described torque at appropriate times by inverter control. Therefore, the IPM is a small-sized motor with excellent controllability.

According to the analysis of the present inventors, when a radial distance DM between a radial armature side surface of the magnet unit and the axial center of the rotor, that is, the radius of the stator core of the general inner rotor is plotted on the horizontal axis, the torque of the rotor surface generating the magnet torque and the reluctance torque is as shown in fig. 43.

While the magnet torque is expressed by the following equation (eq1), and the potential thereof is determined by the magnetic field strength generated by the permanent magnet, the reluctance torque is expressed by the following equation (eq2), and the magnitude of the inductance, particularly the q-axis inductance, determines the potential thereof.

Magnet torque k. psi. Iq. eq1

Reluctance torque k (Lq-Ld) · (Lq · Id · · eq · 2)

Here, the magnitude of the magnetic field strength of the permanent magnet and the inductance of the winding are compared with DM. The strength of the magnetic field generated by the permanent magnet, i.e. the magnetic flux Ψ, is proportional to the total area of the permanent magnet on the face opposite the stator. In the case of a cylindrical rotor, the surface area of the cylinder is defined. Strictly speaking, it is proportional to the specific area of half of the surface of the cylinder, due to the presence of the N and S poles. The surface area of the cylinder is proportional to the radius of the cylinder and the length of the cylinder. That is, if the cylinder length is constant, it is proportional to the radius of the cylinder.

On the other hand, although the inductance Lq of the winding is affected by the shape of the core, the sensitivity is low, and since the inductance Lq of the winding is proportional to the square of the number of turns of the stator winding, it is highly correlated with the number of turns. When μ is the permeability of the magnetic circuit, N is the number of turns, S is the cross-sectional area of the magnetic circuit, and δ is the effective length of the magnetic circuit, the inductance L is μ · N²XS/delta. Since the number of turns of the winding depends on the size of the winding space, the winding space of the stator, that is, the slot area, is determined in the case of a cylindrical motor. As shown in fig. 44, since the shape of the slit is substantially quadrangular, the slit area is proportional to the product a × b of the circumferential length a and the radial length b.

The length of the cutting groove in the circumferential direction is proportional to the diameter of the cylinder because the length increases as the diameter of the cylinder increases. The length dimension in the radial direction of the cutting groove is proportional to the diameter of the cylinder. That is, the area of the cut groove is proportional to the square of the diameter of the cylinder. Further, it can also be seen from the above equation (eq2) that the reluctance torque is proportional to the square of the stator current, and therefore the performance of the rotating electric machine is determined by how much current flows, and the performance depends on the slot area of the stator. In summary, if the length of the cylinder is constant, the reluctance torque is proportional to the square of the diameter of the cylinder. Fig. 43 is a graph plotting the relationship between the magnet torque, the reluctance torque, and the DM based on this.

As shown in fig. 43, the magnet torque increases linearly with respect to DM, and the reluctance torque increases quadratically with respect to DM. It can be seen that when DM is relatively small, magnet torque dominates, and as the stator core radius becomes larger, reluctance torque dominates. The inventors of the present application reached the following conclusions: under predetermined conditions, the intersection point of the magnet torque and the reluctance torque in fig. 43 is approximately in the vicinity of the radius of the stator core, which is 50 mm. That is, in a 10 kW-class motor in which the radius of the stator core is sufficiently larger than 50mm, since the use of reluctance torque is currently the mainstream, it is difficult to eliminate the core, and this is one of the reasons why the non-slotted structure is not adopted in the field of large-sized equipment.

In the case of a rotating electrical machine in which a stator uses an iron core, magnetic saturation of the iron core is always a technical problem. In particular, in the radial gap type rotating electrical machine, the longitudinal sectional shape of the rotating shaft is fan-shaped for each magnetic pole, the magnetic path width becomes narrower toward the inner peripheral side of the apparatus, and the inner peripheral side dimension of the tooth portion forming the notch determines the performance limit of the rotating electrical machine. Even when any high-performance permanent magnet is used, the performance of the permanent magnet cannot be sufficiently exhibited when magnetic saturation occurs in the above portion. In order to prevent the magnetic saturation in the above-described portion, the inner peripheral diameter is designed to be large, which leads to an increase in size of the apparatus.

For example, in a distributed-winding rotary electric machine, if a three-phase winding is used, each magnetic pole is divided by three to six pole teeth and flows, but since the magnetic flux tends to concentrate on the pole teeth in the circumferential front direction, the magnetic flux does not uniformly flow in the three to six pole teeth. In this case, the magnetic flux flows concentratedly in a part (for example, one or two) of the pole teeth, and the pole teeth magnetically saturated as the rotor rotates also move in the circumferential direction. This also becomes a main cause of the notch ripple.

In summary, in the rotary electric machine having the grooveless structure with the DM of 50mm or more, it is desired to remove the pole teeth to eliminate the magnetic saturation. However, when the pole teeth are removed, the magnetic resistance of the magnetic circuit in the rotor and the stator increases, resulting in a decrease in the torque of the rotary electric machine. For example, the air gap between the rotor and the stator may become large as a reason for the increase in magnetic resistance. Therefore, in the rotary electric machine having the grooveless structure in which the DM is 50mm or more, there is room for improvement in torque enhancement. Therefore, in the rotary electric machine having the grooveless structure in which the DM is 50mm or more, there is a great advantage in applying the structure capable of enhancing the torque.

In addition, not limited to the rotating electric machine of the outer rotor structure, the rotating electric machine of the inner rotor structure may be configured such that the radial distance DM between the surface of the magnet unit on the armature side in the radial direction and the axial center of the rotor is 50mm or more.

In the stator winding 51 of the rotating electrical machine 10, the straight portion 83 of the lead wire 82 may be formed in a single layer in the radial direction. When the linear portion 83 is arranged in a plurality of layers radially inward and outward, the number of the layers may be arbitrary, and 3 layers, 4 layers, 5 layers, 6 layers, and the like may be provided.

For example, in the configuration of fig. 2, the rotary shaft 11 is provided to protrude in the axial direction toward both one end side and the other end side of the rotary electric machine 10, but this may be modified so as to protrude only toward one end side. In this case, the rotary shaft 11 is preferably provided with a portion cantilevered by the bearing unit 20 as an end portion, and extends axially outward thereof. In the present configuration, since the rotary shaft 11 does not protrude into the inverter unit 60, the internal space of the inverter unit 60, and more specifically, the internal space of the cylindrical portion 71 can be used.

In the rotating electrical machine 10 having the above-described configuration, the non-conductive grease is used for the bearings 21 and 22, but it is possible to change this configuration and use the conductive grease for the bearings 21 and 22. For example, conductive grease containing metal particles, carbon particles, or the like is used.

As a structure for rotatably supporting the rotary shaft 11, bearings may be provided at two positions on one end side and the other end side in the axial direction of the rotor 40. In this case, in the configuration of fig. 1, the bearings are preferably provided at two locations on one end side and the other end side with the inverter unit 60 interposed therebetween.

In the rotating electrical machine 10 having the above-described configuration, the intermediate portion 45 of the magnet holder 41 in the rotor 40 has the inner shoulder 49a and the annular outer shoulder 49b, but may be configured to have a flat surface without providing the shoulders 49a and 49 b.

In the rotating electric machine 10 having the above-described configuration, the conductor 82a is formed as an aggregate of the plurality of strands 86 in the lead wire 82 of the stator winding 51, but this may be modified and a rectangular lead wire having a rectangular cross section may be used as the lead wire 82. Further, a round wire having a circular or elliptical cross section may be used as the wire 82.

In the rotating electrical machine 10 having the above-described configuration, the inverter unit 60 is provided on the radially inner side of the stator 50, but in addition to this, the inverter unit 60 may not be provided on the radially inner side of the stator 50. In this case, the inner region of the stator 50 on the radially inner side can be used as a space. Further, a member different from the inverter unit 60 may be disposed in the internal region.

In the rotating electrical machine 10 configured as described above, the housing 30 may not be included. In this case, the rotor 40, the stator 50, and the like may be held by a part of a rim or another vehicle component, for example.

(As the vehicle in-wheel motor implementation mode)

Next, an embodiment in which the rotating electrical machine is integrally provided as an in-wheel motor on a wheel of a vehicle will be described. Fig. 45 is a perspective view showing a wheel 400 and its peripheral structure of an in-wheel motor structure, fig. 46 is a vertical sectional view of the wheel 400 and its peripheral structure, and fig. 47 is an exploded perspective view of the wheel 400. Each of the above figures is a perspective view of the wheel 400 as viewed from the vehicle inside. Further, in the vehicle, the in-wheel motor structure of the present embodiment can be applied in various forms, for example, in a vehicle having two wheels respectively at the front and rear of the vehicle, the in-wheel motor structure of the present embodiment can be applied to two wheels at the front side of the vehicle, two wheels at the rear side of the vehicle, or four wheels at the front and rear of the vehicle. However, the present invention is also applicable to a vehicle in which at least one of the front and rear of the vehicle is one wheel. The in-wheel motor is an application example as a vehicle drive unit.

As shown in fig. 45 to 47, wheel 400 includes a well-known pneumatic tire, i.e., a tire 401, a rim 402 fixed to the inner peripheral side of tire 401, and a rotating electrical machine 500 fixed to the inner peripheral side of rim 402. The rotating electric machine 500 includes: a portion including a stator (stator), i.e., a fixing portion; and a rotating portion which is a portion including a rotor (rotating member), the fixed portion being fixed to the vehicle body side, and the rotating portion being fixed to the rim 402, the tire 401 and the rim 402 being rotated by rotation of the rotating portion. Further, a detailed structure including a stationary portion and a rotating portion in the rotating electrical machine 500 will be described later.

Further, as the peripheral devices, a suspension device for holding the wheel 400 to a vehicle body, not shown, a steering device for changing the direction of the wheel 400, and a brake device for braking the wheel 400 are mounted on the wheel 400.

The suspension device is an independent suspension type suspension, and any form such as a trailing arm type, a strut type, a trailing arm type, a multi-link type, and the like can be applied. In the present embodiment, as the suspension device, a lower arm 411 is provided in a direction extending toward the vehicle body center side, and a suspension arm 412 and a spring 413 are provided in a direction extending in the vertical direction. The suspension arm 412 is preferably configured as a shock absorber, for example. However, detailed illustration thereof is omitted. The lower arm 411 and the suspension arm 412 are respectively connected to the vehicle body side, and to a disk-shaped base plate 405 fixed to a fixed portion of the rotary electric machine 500. As shown in fig. 46, on the rotating electric machine 500 side (base plate 405 side), the lower arm 411 and the suspension arm 412 are supported by support shafts 414, 415 in a coaxial state with each other.

Further, as the steering device, for example, a rack & pinion type structure, a ball & nut type structure, a hydraulic power steering system, and an electric power steering system can be applied. In the present embodiment, a rack gear 421 and a tie rod 422 are provided as a steering device, and the rack gear 421 is connected to the base plate 405 on the rotary electric machine 500 side via the tie rod 422. In this case, when the rack device 421 is operated in accordance with rotation of a steering shaft, not shown, the tie rod 422 moves in the vehicle lateral direction. Thereby, the wheel 400 rotates about the support shafts 414 and 415 of the lower arm 411 and the suspension arm 412, and the wheel direction is changed.

As the brake device, a disc brake and a drum brake are suitably applied. In the present embodiment, as the brake device, a disc rotor 431 fixed to the rotation shaft 501 of the rotating electrical machine 500 and a caliper 432 fixed to the base plate 405 on the rotating electrical machine 500 side are provided. In the caliper 432, the pad is operated by hydraulic pressure or the like, and by pressing the pad against the disc rotor 431, a braking force due to friction is generated, and the rotation of the wheel 400 is stopped.

Further, a storage duct 440 for storing the harness H1 and the cooling pipe H2 extending from the rotating electric machine 500 is attached to the wheel 400. The storage pipe 440 is provided to extend from the end of the rotating electrical machine 500 on the fixing portion side along the end surface of the rotating electrical machine 500, and is fixed to the suspension arm 412 in this state while avoiding the suspension arm 412. Thereby, the positional relationship between the connection portion of the suspension arm 412 that houses the pipe 440 and the base plate 405 is fixed. Therefore, stress due to vehicle vibration or the like in the harness H1 and the cooling pipe H2 can be suppressed. The harness H1 is connected to a vehicle-mounted power supply unit or a vehicle-mounted ECU, not shown, and the cooling pipe H2 is connected to a radiator, not shown.

Next, the structure of the rotating electric machine 500 used as an in-wheel motor will be described in detail. In the present embodiment, an example in which the rotating electrical machine 500 is applied to an in-wheel motor is shown. Rotating electric machine 500 has excellent operating efficiency and output as compared with a motor of a vehicle drive unit having a reduction gear as in the related art. That is, if the rotating electric machine 500 can be used for an application that can achieve a practical price by reducing the cost as compared with the related art, it can be used as a motor for an application other than a vehicle driving unit. Even in this case, excellent performance can be exhibited as in the case of application to an in-wheel motor. The operating efficiency is an index used in a test in a running mode in which the fuel efficiency of the vehicle is derived.

Fig. 48 to 51 show an outline of the rotating electric machine 500. Fig. 48 is a side view of the rotating electric machine 500 as viewed from the protruding side (vehicle inside) of the rotating shaft 501, fig. 49 is a vertical sectional view of the rotating electric machine 500 (sectional view taken along line 49-49 in fig. 48), fig. 50 is a horizontal sectional view of the rotating electric machine 500 (sectional view taken along line 50-50 in fig. 49), and fig. 51 is an exploded sectional view in which the components of the rotating electric machine 500 are exploded. In the following description, in fig. 51, a direction extending outward of the vehicle body is referred to as an axial direction, and a direction extending radially from the rotation shaft 501 is referred to as a radial direction, and in fig. 48, both directions extending circumferentially from any point other than the rotation center of the rotation portion on a center line drawn to form a cross section 49 passing through the center of the rotation shaft 501, in other words, the rotation center of the rotation portion, are referred to as circumferential directions. In other words, the circumferential direction may be any of a clockwise direction or a counterclockwise direction starting from any point on the cross section 49. In addition, from the vehicle mounted state, the right side in fig. 49 is the vehicle outside, and the left side is the vehicle inside. In other words, in the vehicle mounted state, rotor 510 described later is disposed further toward the outside of the vehicle body than rotor cover 670.

The rotating electric machine 500 of the present embodiment is an outer rotor type surface magnet type rotating electric machine. The rotary electric machine 500 generally includes a rotor 510, a stator 520, an inverter unit 530, a bearing 560, and a rotor cover 670. The above-described members are arranged coaxially with respect to a rotating shaft 501 integrally provided in a rotor 510, and are assembled in the axial direction in a predetermined order, thereby constituting a rotating electric machine 500.

In the rotating electric machine 500, the rotor 510 and the stator 520 are each cylindrical and face each other with an air gap therebetween. The rotor 510 rotates integrally with the rotary shaft 501, whereby the rotor 510 rotates radially outside the stator 520. The rotor 510 corresponds to a "field element", and the stator 520 corresponds to an "armature".

The rotor 510 includes a substantially cylindrical rotor frame 511 and an annular magnet unit 512 fixed to the rotor frame 511. The rotation shaft 501 is fixed to the rotor frame 511.

The rotor frame 511 has a cylindrical portion 513. The magnet unit 512 is fixed to the inner circumferential surface of the cylindrical portion 513. That is, the magnet unit 512 is provided in a state of being surrounded by the cylindrical portion 513 of the rotor frame 511 from the outside in the radial direction. Further, the cylindrical portion 513 has a first end and a second end opposite in the axial direction thereof. The first end is located in the direction of the vehicle body outer side, and the second end is located in the direction in which the base plate 405 is present. In the rotor frame 511, an end plate 514 is continuously provided at a first end of the cylindrical portion 513. That is, the cylindrical portion 513 and the end plate 514 are integrally configured. The second end of the cylindrical portion 513 is open. The rotor frame 511 is formed of, for example, a cold-rolled steel sheet (SPCC, SPHC thicker than the SPCC sheet) having sufficient mechanical strength, forged steel, Carbon Fiber Reinforced Plastic (CFRP), or the like.

The axial length of the rotary shaft 501 is longer than the axial dimension of the rotor frame 511. In other words, the rotary shaft 501 projects toward the open end side (vehicle inside direction) of the rotor frame 511, and the brake device and the like described above are attached to the end of the projecting side.

The end plate 514 of the rotor frame 511 has a through hole 514a formed in the center thereof. The rotary shaft 501 is fixed to the rotor frame 511 in a state inserted through the through hole 514a of the end plate 514. The rotary shaft 501 has a flange 502 extending in a direction intersecting with (orthogonal to) the axial direction at a portion to which the rotor frame 511 is fixed, and the rotary shaft 501 is fixed to the rotor frame 511 in a state where the flange is surface-bonded to the vehicle outer surface of the end plate 514. In the wheel 400, the rim 402 is fixed using a fastener such as a bolt erected from the flange 502 of the rotary shaft 501 toward the vehicle outer side.

In addition, the magnet unit 512 is composed of a plurality of permanent magnets arranged to alternately change polarity along the circumferential direction of the rotor 510. Thus, the magnet unit 512 has a plurality of magnetic poles in the circumferential direction. The permanent magnet is fixed to the rotor frame 511 by, for example, adhesion. Magnet unit 512 has the structure described as magnet unit 42 in fig. 8 and 9 of the first embodiment, and a permanent magnet is configured using a sintered neodymium magnet having an intrinsic coercive force of 400 kA/m or more and a residual magnetic flux density Br of 1.0T or more.

Like the magnet unit 42 of fig. 9 and the like, the magnet unit 512 has a first magnet 91 and a second magnet 92 which are respectively polar anisotropic magnets and differ in polarity from each other. As described with reference to fig. 8 and 9, the directions of the easy magnetization axes of the magnets 91 and 92 are different between the d-axis side (portion close to the d-axis) in which the direction of the easy magnetization axis is close to the direction parallel to the d-axis and the q-axis side (portion close to the q-axis) in which the direction of the easy magnetization axis is close to the direction orthogonal to the q-axis. Further, a magnet magnetic path in the shape of a circular arc is formed in accordance with the orientation corresponding to the direction of the easy magnetization axis. In the magnets 91 and 92, the easy magnetization axis may be parallel to the d-axis on the d-axis side and may be perpendicular to the q-axis on the q-axis side. In short, the magnet unit 512 is configured to be oriented such that the direction of the easy axis of magnetization is more parallel to the d axis at the magnetic pole center, i.e., the d axis side than the q axis side, which is the magnetic pole boundary.

According to the respective magnets 91, 92, the magnet magnetic flux at the d-axis is enhanced, and the magnetic flux variation near the q-axis is suppressed. This makes it possible to realize magnets 91 and 92 with a reduced surface magnetic flux change from the q-axis to the d-axis in each magnetic pole. As the magnet unit 512, the structure of the magnet unit 42 shown in fig. 22 and 23 and the structure of the magnet unit 42 shown in fig. 30 can be used.

The magnet unit 512 may have a rotor core (back yoke) formed by laminating a plurality of electromagnetic steel plates in the axial direction on the cylindrical portion 513 side of the rotor frame 511, that is, on the outer circumferential surface side. That is, the rotor core may be provided radially inside the cylindrical portion 513 of the rotor frame 511, and the permanent magnets (magnets 91 and 92) may be provided radially inside the rotor core.

As shown in fig. 47, the cylindrical portion 513 of the rotor frame 511 is formed with recesses 513a extending in the axial direction at predetermined intervals in the circumferential direction. As shown in fig. 52, the concave portion 513a is formed by, for example, press working, and a convex portion 513b is formed on the inner circumferential surface side of the cylindrical portion 513 at a position on the back side of the concave portion 513 a. On the other hand, on the outer circumferential surface side of the magnet unit 512, a concave portion 512a is formed in conformity with the convex portion 513b of the cylindrical portion 513, and the convex portion 513b of the cylindrical portion 513 enters the concave portion 512a, thereby suppressing positional displacement in the circumferential direction of the magnet unit 512. That is, the convex portion 513b on the rotor frame 511 side functions as a rotation stopper of the magnet unit 512. The convex portion 513b may be formed by any method other than press working.

In fig. 52, the direction of the magnet magnetic circuit of the magnet unit 512 is indicated by an arrow. The magnetic flux path of the magnet extends in an arc shape so as to straddle the q-axis as a boundary of the magnetic poles, and is oriented in a direction parallel or nearly parallel to the d-axis on the d-axis as a center of the magnetic poles. In the magnet unit 512, a recess 512b is formed at each position corresponding to the q-axis on the inner peripheral surface side thereof. In this case, in the magnet unit 512, the length of the magnet magnetic path is different between the side close to the stator 520 (lower side in the figure) and the side far from the stator 520 (upper side in the figure), the length of the magnet magnetic path on the side close to the stator 520 becomes shorter, and the recess 512b is formed at the position where the length of the magnet magnetic path becomes shortest. That is, it is considered that the magnet unit 512 is difficult to generate a sufficient magnet magnetic flux at a portion where the magnet magnetic path length is short, and the magnet is removed at a portion where the magnet magnetic flux is weak.

Here, the longer the length of the magnetic circuit passing through the inside of the magnet, the higher the effective magnetic flux density Bd of the magnet. Further, the permeability coefficient Pc and the effective magnetic flux density Bd of the magnet are in a relationship such that one becomes higher and the other becomes higher. According to the configuration of fig. 52, the amount of the magnet can be reduced while suppressing a decrease in the magnetic permeability Pc, which is an index of the height of the effective magnetic flux density Bd of the magnet. In the B-H coordinate, the operating point is an intersection of a magnetic flux guide straight line corresponding to the shape of the magnet and the demagnetization curve, and the magnetic flux density at the operating point is the effective magnetic flux density Bd of the magnet. In the rotating electric machine 500 of the present embodiment, the amount of iron in the stator 520 is reduced, and in this configuration, a method of setting a magnetic path crossing the q-axis is extremely effective.

Further, the recess 512b of the magnet unit 512 can serve as an air passage extending in the axial direction. Therefore, the air cooling performance can be improved.

Next, the structure of the stator 520 will be described. Stator 520 includes stator winding 521 and stator core 522. Fig. 53 is a perspective view of the stator winding 521 and the stator core 522 exploded and shown.

The stator winding 521 is formed by winding a plurality of phase windings formed in a substantially cylindrical shape (annular shape), and a stator core 522 as a base member is attached to the inside in the radial direction of the stator winding 521. In the present embodiment, the stator winding 521 is configured as a three-phase winding by using U-phase, V-phase, and W-phase windings. Each phase winding is formed by two layers of wires 523 arranged radially inward and outward. The stator 520 is characterized by a flat wire structure having a non-slotting structure and stator windings 521, as with the stator 50 described above, and has the same or similar structure as the stator 50 shown in fig. 8 to 16.

The structure of stator core 522 will be explained. As in the stator core 52 described above, the stator core 522 is formed in a cylindrical shape having a predetermined thickness in the radial direction with a plurality of electromagnetic steel sheets stacked in the axial direction, and the stator winding 521 is assembled on the radially outer side of the stator core 522 on the rotor 510 side. The outer peripheral surface of the stator core 522 has a curved surface shape without unevenness, and in a state where the stator winding 521 is assembled, the lead wires 523 constituting the stator winding 521 are arranged in parallel in the circumferential direction along the outer peripheral surface of the stator core 522. The stator core 522 functions as a support core.

The stator 520 preferably has any one of the following configurations (a) to (C).

(A) In the stator 520, the inter-lead members are provided between the respective lead wires 523 in the circumferential direction, and as the inter-lead members, a magnetic material satisfying a relationship Wt × Bs ≦ Wm × Br is used, where Wt is a circumferential width of the inter-lead member of one magnetic pole, Bs is a saturation magnetic flux density of the inter-lead member, Wm is a circumferential width of the magnet unit 512 of one magnetic pole, and Br is a residual magnetic flux density of the magnet unit 512.

(B) In the stator 520, an inter-wire member is provided between the respective wires 523 in the circumferential direction, and a non-magnetic material is used as the inter-wire member.

(C) In the stator 520, no inter-wire member is provided between the respective wires 523 in the circumferential direction.

According to the configuration of the stator 520, the inductance can be reduced as compared with a rotating electric machine having a normal pole tooth configuration in which pole teeth (iron cores) for establishing a magnetic circuit are provided between the respective lead portions as the stator winding. Specifically, the inductance can be made below 1/10. In this case, since the impedance decreases with a decrease in inductance, the output power with respect to the input power is increased in the rotating electrical machine 500, which can contribute to an increase in torque. Further, a rotating electrical machine with a large output can be provided as compared with a rotating electrical machine using an embedded magnet type rotor that performs torque output using a voltage of an impedance component (in other words, using reluctance torque).

In the present embodiment, the stator winding 521 and the stator core 522 are integrally molded together with a molding material (insulating member) made of resin or the like, and the molding material is interposed between the respective conductive wires 523 arranged in the circumferential direction. With the above configuration, the stator 520 of the present embodiment corresponds to the configuration of (B) in the above (a) to (C). In addition, in each of the conductive wires 523 adjacent in the circumferential direction, end surfaces in the circumferential direction are in contact with each other or are arranged adjacent to each other with a slight interval therebetween. In the case of the configuration (a), it is preferable that the protrusions be provided on the outer circumferential surface of the stator core 522 in accordance with the orientation of the conductive wires 523 in the axial direction, that is, in accordance with the skew angle in the case of the stator winding 521 having a skew structure, for example.

Next, the structure of the stator winding 521 will be described with reference to fig. 54. Fig. 54 is a front view showing the stator winding 521 spread out in a planar manner, in which fig. 54 (a) shows the respective leads 523 positioned on the outer layer in the radial direction, and fig. 54 (b) shows the respective leads 523 positioned on the inner layer in the radial direction.

The stator winding 521 is formed by winding distributed windings in an annular shape. In the stator winding 521, the lead wire material is wound on both the inner and outer layers in the radial direction, and skew is applied to the respective lead wires 523 on the inner and outer layers in different directions from each other (see fig. 54 a and 54 b). The conductive lines 523 are insulated from each other. The lead 523 is preferably configured as an aggregate of a plurality of strands of wire 86 (see fig. 13). In addition, for example, two wires 523 in the same phase and in the same current-carrying direction are arranged in parallel in the circumferential direction. In the stator winding 521, one lead portion of the same phase is formed by two leads 523 each having two layers in the radial direction and two (i.e., four in total) in the circumferential direction, and is provided one in each magnetic pole.

In the lead portion, it is preferable that a thickness dimension in a radial direction is set smaller than a width dimension in a circumferential direction corresponding to one of the magnetic poles, and thereby the stator winding 521 has a flat lead structure. Specifically, for example, in the stator winding 521, it is preferable that each of the conductive wires 523, which are two layers in the radial direction and four (i.e., eight in total) in the circumferential direction, constitutes one conductive wire portion of the same phase. Alternatively, in the wire cross section of the stator winding 521 shown in fig. 50, the width dimension in the circumferential direction is preferably larger than the thickness dimension in the radial direction. The stator winding 51 shown in fig. 12 may be used as the stator winding 521. However, in this case, it is necessary to secure a space for accommodating the coil side end portions of the stator windings in the rotor frame 511.

In the stator winding 521, the conductive wires 523 are arranged side by side in the circumferential direction while being inclined at a predetermined angle at coil side portions 525 that overlap radially inward and outward with respect to the stator core 522, and are reversed (folded back) axially inward at coil side end portions 526 on both sides axially outward of the stator core 522, thereby realizing continuous connection. Fig. 54 (a) shows the range of the coil side portion 525 and the range of the coil side end portion 526, respectively. The conductive line 523 on the inner layer side and the conductive line 523 on the outer layer side are connected to each other at the coil side end 526, and thus the conductive line 523 is alternately switched between the inner layer side and the outer layer side every time the conductive line 523 is reversed in the axial direction (every time it is folded back) at the coil side end 526. In short, in the stator winding 521, the inner and outer layers of the respective conductive wires 523, which are continuous in the circumferential direction, are switched in accordance with the reversal of the current direction.

In addition, in the stator winding 521, two types of skew having different skew angles are implemented at end regions that are both ends in the axial direction and a central region sandwiched between the end regions. That is, as shown in fig. 55, in the lead 523, the skew angle θ s1 in the central region is different from the skew angle θ s2 in the end region, and the skew angle θ s1 is smaller than the skew angle θ s 2. In the axial direction, the end region is defined by a range including the coil side portion 525. The skew angles θ s1 and θ s2 are the inclination angles at which the respective conductive wires 523 are inclined with respect to the axial direction. The skew angle θ s1 in the central region is preferably determined within an angular range suitable for reducing harmonic components of the magnetic flux generated by energization of the stator winding 521.

The skew angles of the respective wires 523 in the stator winding 521 are different at the central region and the end regions, and the skew angle θ s1 of the central region is smaller than the skew angle θ s2 of the end regions, whereby it is possible to achieve reduction of the coil side ends 526 and increase the winding factor of the stator winding 521. In other words, it is possible to shorten the length of the coil side end portions 526, that is, the length of the wire of the portion protruding from the stator core 522 in the axial direction while ensuring a desired winding ratio. This can reduce the size of the rotating electric machine 500 and improve the torque.

Here, a suitable range of the skew angle θ s1 in the central region will be described. When X conductive wires 523 are arranged in one magnetic pole of the stator winding 521, it is conceivable that an X-order harmonic component is generated by the energization of the stator winding 521. When the number of phases is S and the logarithm is m, X is 2 × S × m. Since the X-th harmonic component is a component constituting a composite wave of the X-1 th harmonic component and the X +1 th harmonic component, the inventors of the present application focused on reducing the X-th harmonic component by reducing at least either the X-1 th harmonic component or the X +1 th harmonic component. From this viewpoint, the inventors of the present application have found that the X-order harmonic component can be reduced by setting the skew angle θ s1 within an angular range of "360 °/(X +1) to 360 °/(X-1)" electrical angle.

For example, when S is 3 and m is 2, the skew angle θ S1 is set within an angle range of "360 °/13 to 360 °/11" in order to reduce harmonic components in which X is 12. That is, the skew angle θ s1 is preferably set to an angle in the range of 27.7 ° to 32.7 °.

By setting the skew angle θ s1 in the central region as described above, the magnetic fluxes of the NS-alternating magnets can be actively linked in the central region, and the winding factor of the stator winding 521 can be increased.

The skew angle θ s2 of the end region is a larger angle than the skew angle θ s1 of the central region. In this case, the angular range of the skew angle θ s2 is "θ s1 < θ s2 < 90 °".

In the stator winding 521, the inner-layer-side conductive wire 523 and the outer-layer-side conductive wire 523 are preferably connected by welding or bonding the ends of the conductive wires 523 to each other or by bending. In the stator winding 521, at one side (i.e., one axial end side) of the coil side end portions 526 on both axial sides, the end portions of the phase windings are electrically connected to a power converter (inverter) via a bus or the like. Therefore, a description will be given here of a configuration in which the coil side end 526 on the bus bar connection side is separated from the coil side end 526 on the opposite side, and the respective lead wires in the coil side end 526 are connected to each other.

As a first configuration, the lead wires 523 are connected to the coil side end 526 on the bus bar connection side by welding, and the lead wires 523 are connected to the coil side end 526 on the opposite side by a method other than welding. As a method other than soldering, for example, connection by bending of a wire material is considered. In the coil side end 526 on the bus bar connection side, it is assumed that the bus bar is connected to the end of each phase winding by welding. Therefore, by configuring to connect the lead wires 523 by welding to the same coil side end 526, the respective welded portions can be realized in a series of steps, and the work efficiency can be improved.

As a second configuration, the respective conductive wires 523 are connected to the coil side end 526 on the bus bar connection side by a method other than welding, and the respective conductive wires 523 are connected to the coil side end 526 on the opposite side by welding. In this case, if the respective conductive wires 523 are connected to the coil side end 526 on the bus bar connection side by welding, a sufficient separation distance needs to be provided between the bus bar and the coil side end 526 in order to avoid contact between the welded portion and the bus bar. This can relax restrictions on the axial length or the bus bar of the stator winding 521.

As a third configuration, the respective lead wires 523 are connected by welding at the coil side end portions 526 on both sides in the axial direction. In this case, the lead material prepared before welding may be a lead material having a short wire length, and the work efficiency can be improved by reducing the number of bending steps.

As a fourth configuration, the respective lead wires 523 are connected to the coil side end portions 526 on both sides in the axial direction by a method other than welding. In this case, the number of welded portions in the stator winding 521 can be reduced as much as possible, and the possibility of occurrence of insulation separation in the welding process can be reduced.

In the step of manufacturing the annular stator winding 521, it is preferable to manufacture a strip winding arranged in a planar shape and then form the strip winding into an annular shape. In this case, in a state where the planar strip winding is formed, it is preferable that the lead wires are welded to each other at the coil edge 526 as necessary. When the planar strip winding is formed into a ring shape, the strip winding is preferably formed into a ring shape by using a cylindrical jig having the same diameter as that of the stator core 522 and winding the cylindrical jig. Alternatively, the strip winding may be directly wound around stator core 522.

The structure of the stator winding 521 may be modified as follows.

For example, in the stator winding 521 shown in fig. 54 (a) and (b), the skew angles of the central region and the end regions may be the same.

In the stator winding 521 shown in fig. 54 (a) and (b), the ends of the circumferentially adjacent in-phase conductive wires 523 may be connected to each other by a crossover portion extending in a direction orthogonal to the axial direction.

The number of layers of the stator winding 521 may be 2 × n (n is a natural number), and the stator winding 521 may be four or six layers other than two layers.

Next, the inverter unit 530 as a power conversion unit will be described. Here, the structure of the inverter unit 530 will be described with reference to fig. 56 and 57, which are exploded sectional views of the inverter unit 530. In fig. 57, each member shown in fig. 56 is shown as two subassemblies.

The inverter unit 530 includes an inverter case 531, a plurality of electrical modules 532 assembled to the inverter case 531, and a bus bar module 533 that electrically connects the electrical modules 532.

The inverter housing 531 includes: a cylindrical outer wall member 541; an inner wall member 542, the inner wall member 542 having a cylindrical shape with an outer periphery smaller than that of the outer wall member 541, and being disposed radially inward of the outer wall member 541; and a boss forming member 543, the boss forming member 543 being fixed to one end side in the axial direction of the inner wall member 542. Each of the members 541-543 is preferably made of a conductive material, for example, Carbon Fiber Reinforced Plastic (CFRP). The inverter housing 531 is configured such that an outer wall member 541 and an inner wall member 542 are overlapped and combined radially inward and outward, and a boss forming member 543 is assembled at one end side in the axial direction of the inner wall member 542. The assembled state is the state shown in fig. 57.

The stator core 522 is fixed to a radially outer side of the outer wall member 541 of the inverter housing 531. Thereby, the stator 520 and the inverter unit 530 are integrally formed.

As shown in fig. 56, a plurality of recesses 541a, 541b, and 541c are formed in the inner peripheral surface of the outer wall member 541, and a plurality of recesses 542a, 542b, and 542c are formed in the outer peripheral surface of the inner wall member 542. Then, the outer wall member 541 and the inner wall member 542 are assembled to each other, thereby forming three hollow portions 544a, 544b, and 544c therebetween (see fig. 57). The central hollow portion 544b serves as a cooling water passage 545 through which cooling water serving as a refrigerant flows. Further, the seals 546 are housed in the hollow portions 544a and 544c on both sides of the hollow portion 544b (cooling water passage 545). The seal 546 closes the hollow portion 544b (the cooling water passage 545). The cooling water passage 545 will be described in detail later.

The boss forming member 543 is provided with a disk-ring-shaped end plate 547 and a boss portion 548 projecting from the end plate 547 toward the inside of the housing. The boss portion 548 is provided in a hollow cylindrical shape. For example, as shown in fig. 51, the boss forming member 543 is fixed to a second end of the first end of the inner wall member 542 in the axial direction and a second end of the protruding side (i.e., the vehicle interior side) of the rotary shaft 501 opposite thereto. In addition, in the wheel 400 shown in fig. 45 to 47, the base plate 405 is fixed to the inverter case 531 (more specifically, the end plate 547 of the boss forming member 543).

The inverter housing 531 is configured to have a double-layer peripheral wall in the radial direction with the axial center as the center, and of the double-layer peripheral wall, the outer peripheral wall is formed by the outer wall member 541 and the inner wall member 542, and the inner peripheral wall is formed by the boss portion 548. In the following description, the outer peripheral wall formed by the outer wall member 541 and the inner wall member 542 is also referred to as "outer peripheral wall WA 1", and the inner peripheral wall formed by the boss portion 548 is also referred to as "inner peripheral wall WA 2".

The inverter housing 531 forms an annular space between the outer peripheral wall WA1 and the inner peripheral wall WA2, and a plurality of electrical modules 532 are arranged in the annular space in the circumferential direction. The electric module 532 is fixed to the inner peripheral surface of the inner wall member 542 by adhesion, screw fastening, or the like. In the present embodiment, the inverter housing 531 corresponds to a "housing member", and the electric module 532 corresponds to an "electric component".

A bearing 560 is housed inside the inner peripheral wall WA2 (boss portion 548), and the rotary shaft 501 is rotatably supported by the bearing 560. The bearing 560 is a hub bearing that rotatably supports the wheel 400 at the wheel center portion. The bearing 560 is provided at a position overlapping with the rotor 510, the stator 520, and the inverter unit 530 in the axial direction. In the rotating electrical machine 500 according to the present embodiment, the magnet unit 512 can be made thin by orienting the rotor 510, and the stator 520 can be made thin by adopting a non-slotted structure or a flat conductor structure, whereby the radial thickness dimension of the magnetic circuit portion can be reduced and the hollow space on the radial inner side of the magnetic circuit portion can be expanded. This allows the magnetic circuit portion, the inverter unit 530, and the bearing 560 to be arranged in a radially stacked state. The boss portion 548 is a bearing holding portion that holds the bearing 560 at the inner side thereof.

The bearing 560 is, for example, a radial ball bearing, and includes: a cylindrical inner ring 561; an outer ring 562 which is cylindrical and has a diameter larger than that of the inner ring 561 and is disposed radially outside the inner ring 561; and a plurality of balls 563 arranged between the inner ring 561 and the outer ring 562. The bearing 560 is fixed to the inverter housing 531 by assembling the outer ring 562 to the boss forming member 543, and the inner ring 561 is fixed to the rotary shaft 501. The inner ring 561, the outer ring 562, and the balls 563 are made of a metal material such as carbon steel.

The inner ring 561 of the bearing 560 has a cylindrical portion 561a that houses the rotary shaft 501, and a flange 561b that extends from one axial end of the cylindrical portion 561a in a direction that intersects (is orthogonal to) the axial direction. The flange 561b is a portion that abuts the end plate 514 of the rotor frame 511 from the inside, and the rotor frame 511 is held in a state sandwiched between the flange 502 of the rotary shaft 501 and the flange 561b of the inner ring 561 in a state where the bearing 560 is assembled to the rotary shaft 501. In this case, the angles at which the flange 502 of the rotary shaft 501 and the flange 561b of the inner ring 561 intersect with each other in the axial direction are the same (both are right angles in the present embodiment), and the rotor frame 511 is held in a state of being sandwiched between the flanges 502, 561 b.

According to the structure in which the rotor frame 511 is supported from the inside by the inner ring 561 of the bearing 560, the angle of the rotor frame 511 with respect to the rotation shaft 501 can be maintained at an appropriate angle, and the parallelism of the magnet unit 512 with respect to the rotation shaft 501 can be maintained well. This makes it possible to improve the resistance to vibration and the like even in a configuration in which the rotor frame 511 is expanded in the radial direction.

Next, the electric module 532 housed in the inverter case 531 will be described.

The plurality of electrical modules 532 are formed by dividing electrical components such as a semiconductor switching element and a smoothing capacitor constituting a power converter into a plurality of parts and modularizing the parts, and each of the electrical modules 532 includes: a switch module 532A having a semiconductor switch element as a power element; and a capacitor module 532B having a smoothing capacitor.

As shown in fig. 49 and 50, a plurality of spacers 549 having flat surfaces for mounting the electric module 532 are fixed to the inner peripheral surface of the inner wall member 542, and the electric module 532 is mounted on the spacers 549. That is, since the inner peripheral surface of the inner wall member 542 is a curved surface and the mounting surface of the electric module 532 is a flat surface, a flat surface is formed on the inner peripheral surface side of the inner wall member 542 by the spacer 549 and the electric module 532 is fixed to the flat surface.

It is not essential to interpose the spacer 549 between the inner wall member 542 and the electric module 532, and the electric module 532 can be directly attached to the inner wall member 542 by making the inner peripheral surface of the inner wall member 542 a flat surface or making the attachment surface of the electric module 532a curved surface. The electric module 532 can be fixed to the inverter case 531 without contacting the inner peripheral surface of the inner wall member 542. For example, the electrical module 532 is fixed to the end plate 547 of the boss forming member 543. The switch module 532A may be fixed in a contact state to the inner peripheral surface of the inner wall member 542, and the capacitor module 532B may be fixed in a non-contact state to the inner peripheral surface of the inner wall member 542.

When the spacers 549 are provided on the inner peripheral surface of the inner wall member 542, the outer peripheral wall WA1 and the spacers 549 correspond to "cylindrical portions". In the case where the spacer 549 is not used, the outer peripheral wall WA1 corresponds to a "cylindrical portion".

As described above, the cooling water passage 545 through which the cooling water serving as the refrigerant flows is formed in the outer peripheral wall WA1 of the inverter housing 531, and the electric modules 532 are cooled by the cooling water flowing through the cooling water passage 545. As the refrigerant, cooling oil may be used instead of cooling water. The cooling water passage 545 is provided in an annular shape along the outer peripheral wall WA1, and the cooling water flowing through the cooling water passage 545 flows from the upstream side to the downstream side via each of the electric modules 532. In the present embodiment, the cooling water passage 545 is provided in an annular shape so as to overlap the electric modules 532 in the radial direction and surround the electric modules 532.

The inner wall member 542 is provided with an inlet passage 571 through which cooling water flows into the cooling water passage 545, and an outlet passage 572 through which cooling water flows out from the cooling water passage 545. As described above, the plurality of electrical modules 532 are fixed to the inner peripheral surface of the inner wall member 542, and in the above configuration, the interval between the electrical modules adjacent in the circumferential direction is expanded at only one point as compared with the other portions, and a part of the inner wall member 542 protrudes radially inward at the expanded portion, thereby forming the protruding portion 573. Further, the projecting portion 573 is provided with an inlet passage 571 and an outlet passage 572 in a state of being arranged laterally in the radial direction.

Fig. 58 shows the arrangement state of each electrical module 532 in the inverter case 531. Fig. 58 is a longitudinal sectional view similar to fig. 50.

As shown in fig. 58, the electrical modules 532 are arranged in the circumferential direction with the interval between the electrical modules in the circumferential direction being the first interval INT1 or the second interval INT 2. The second interval INT2 is a wider interval than the first interval INT 1. Each interval INT1, INT2 is a distance between the center positions of two circumferentially adjacent electrical modules 532, for example. In this case, the interval between the circumferentially adjacent electric modules without sandwiching the protruding portion 573 is the first interval INT1, and the interval between the circumferentially adjacent electric modules sandwiching the protruding portion 573 is the second interval INT 2. That is, the interval between the circumferentially adjacent electric modules is partially enlarged, and the projection 573 is provided, for example, at the central portion of the enlarged interval (the second interval INT 2).

Each of the intervals INT1 and INT2 may be a distance of an arc between the center positions of two circumferentially adjacent electric modules 532 on the same circle centered on the rotation shaft 501. Alternatively, the intervals between the electrical modules in the circumferential direction may be defined as angular intervals θ i1, θ i2(θ i1 < θ i2) centered on the rotation axis 501.

In the configuration shown in fig. 58, the electric modules 532 arranged at the first interval INT1 are arranged in a state of being separated from each other in the circumferential direction (non-contact state), but instead of this configuration, the electric modules 532 may be arranged in a state of being in contact with each other in the circumferential direction.

As shown in fig. 48, a water passage port 574 in which passage end portions of an inlet passage 571 and an outlet passage 572 are formed is provided in an end plate 547 of a boss forming member 543. A circulation path 575, through which cooling water circulates, is connected to the inlet passage 571 and the outlet passage 572. The circulation path 575 is constituted by a cooling water pipe. A pump 576 and a heat sink 577 are provided in the circulation path 575, and the cooling water circulates through the cooling water passage 545 and the circulation path 575 as the pump 576 is driven. The pump 576 is an electric pump. The heat sink 577 is a heat sink that releases heat of cooling water to the atmosphere, for example.

As shown in fig. 50, since the stator 520 is disposed outside the outer peripheral wall WA1 and the electric module 532 is disposed inside, heat of the stator 520 is transmitted from the outside to the outer peripheral wall WA1 and heat of the electric module 532 is transmitted from the inside to the outer peripheral wall WA 1. In this case, the cooling water flowing through the cooling water passage 545 can cool the stator 520 and the electric module 532 at the same time, so that the heat of the heat generating components in the rotary electric machine 500 can be efficiently released.

Here, an electrical configuration of the power converter will be described with reference to fig. 59.

As shown in fig. 59, the stator winding 521 is composed of a U-phase winding, a V-phase winding, and a W-phase winding, and the inverter 600 is connected to the stator winding 521. The inverter 600 is configured by a full bridge circuit having the same number of upper and lower arms as the number of phases, and a series connection body including an upper arm switch 601 and a lower arm switch 602 is provided for each phase. The switches 601 and 602 are turned on and off by the drive circuit 603, and the windings of the respective phases are energized by the on and off. Each of the switches 601 and 602 is formed of a semiconductor switching element such as a MOSFET or an IGBT. In the upper and lower arms of each phase, a capacitor 604 for supplying electric charge necessary for switching to each of the switches 601 and 602 is connected in parallel to the series connection body of the switches 601 and 602.

The control device 607 includes a microcomputer having a CPU and various memories, and performs energization control by turning on and off the switches 601 and 602 based on various kinds of detection information in the rotating electrical machine 500 and requests for power running drive and power generation. The controller 607 performs on/off control of the switches 601 and 602 by PWM control or rectangular wave control at a predetermined switching frequency (carrier frequency), for example. The controller 607 may be a built-in controller built in the rotating electric machine 500 or may be an external controller provided outside the rotating electric machine 500.

In the rotating electrical machine 500 of the present embodiment, the inductance of the stator 520 is reduced, and therefore, the electrical time constant is reduced, and when the electrical time constant is reduced, it is desirable to increase the switching frequency (carrier frequency) and increase the switching speed. In this regard, since the capacitor 604 for charge supply is connected in parallel to the series connection body of the switches 601 and 602 of each phase, the wiring inductance is reduced, and even with a configuration in which the switching speed is increased, an appropriate surge countermeasure can be taken.

The high-potential side terminal of the inverter 600 is connected to the positive terminal of the dc power supply 605, and the low-potential side terminal is connected to the negative terminal (ground) of the dc power supply 605. Further, a smoothing capacitor 606 is connected in parallel to the dc power supply 605 between the high potential side terminal and the low potential side terminal of the inverter 600.

The switch module 532A includes switches 601 and 602 (semiconductor switching elements) as heat generating components, a drive circuit 603 (specifically, an electric element constituting the drive circuit 603), and a capacitor 604 for supplying electric charge. The capacitor module 532B further includes a smoothing capacitor 606 as a heat generating component. Fig. 60 shows a specific configuration example of the switch module 532A.

As shown in fig. 60, the switch module 532A has a module case 611 as a housing case, and has switches 601 and 602 for one phase, a drive circuit 603, and a capacitor 604 for charge supply housed in the module case 611. The driver circuit 603 is configured as an exclusive IC or a circuit board, and is provided in the switch module 532A.

The module case 611 is made of an insulating material such as resin, for example, and is fixed to the outer peripheral wall WA1 with its side surface in contact with the inner peripheral surface of the inner wall member 542 of the inverter unit 530. The module case 611 is filled with a molding material such as resin. Inside the module case 611, the switches 601 and 602 and the drive circuit 603, the switches 601 and 602, and the capacitor 604 are electrically connected by wiring 612, respectively. In more detail, the switch module 532A is attached to the outer peripheral wall WA1 via the spacer 549, but the spacer 549 is not shown.

In a state where the switch module 532A is fixed to the outer peripheral wall WA1, the cooling performance of the switch module 532A is higher on the outer peripheral wall WA1 side, that is, on the cooling water passage 545 side, and therefore the arrangement order of the switches 601 and 602, the driver circuit 603, and the capacitor 604 is determined according to the cooling performance. Specifically, since the switches 601 and 602, the capacitor 604, and the drive circuit 603 generate heat in this order from large to small, these components are arranged in the order of the switches 601 and 602, the capacitor 604, and the drive circuit 603 from the side close to the outer peripheral wall WA1 in accordance with the order of magnitude of the generated heat. Further, the contact surface of the switch module 532A is preferably smaller than the contact surface of the inner peripheral surface of the inner wall member 542.

Although the capacitor module 532B is not shown in detail, the capacitor module 532B is configured to accommodate the capacitor 606 in a module case having the same shape and size as the switch module 532A. Similarly to the switch module 532A, the capacitor module 532B is fixed to the outer peripheral wall WA1 with the side surface of the module case 611 in contact with the inner peripheral surface of the inner wall member 542 of the inverter housing 531.

The switch modules 532A and the capacitor modules 532B may not necessarily be arranged on concentric circles at the radially inner side of the outer peripheral wall WA1 of the inverter housing 531. For example, the switch module 532A may be disposed radially inward of the capacitor module 532B or may be disposed in reverse.

When the rotary electric machine 500 is driven, heat is exchanged between the switching modules 532A and 532B and the cooling water passage 545 via the inner wall member 542 of the outer peripheral wall WA 1. Thereby, cooling in the switch module 532A and the capacitor module 532B is performed.

Each of the electric modules 532 may be configured to introduce cooling water into the inside thereof and cool the cooling water inside the module. Here, the water cooling structure of the switch module 532A will be described with reference to (a) and (b) of fig. 61. Fig. 61 (a) is a vertical sectional view showing a sectional structure of the switch module 532A in a direction crossing the outer peripheral wall WA1, and fig. 61 (B) is a sectional view taken along line 61B-61B of fig. 61 (a).

As shown in fig. 61 (a) and (b), the switch module 532A includes a module case 611, switches 601 and 602 of one phase, a drive circuit 603, and a capacitor 604, and a cooling device including a pair of pipe sections 621 and 622, and a cooler 623, as in fig. 60. In the cooling device, the pair of pipe portions 621 and 622 includes an inflow pipe portion 621 through which cooling water flows from the cooling water passage 545 of the outer peripheral wall WA1 into the cooler 623, and an outflow pipe portion 622 through which cooling water flows from the cooler 623 into the cooling water passage 545. The cooler 623 is provided according to the object to be cooled, and one or more stages of coolers 623 are used in the cooling device. In the configuration of fig. 61 (a) and (b), two-stage coolers 623 are provided in a direction away from the cooling water passage 545, that is, in a radial direction of the inverter unit 530, in a state of being separated from each other, and cooling water is supplied to each of the coolers 623 through a pair of pipe sections 621 and 622. The cooler 623 is formed, for example, with a hollow inside. However, an inner fin may be provided inside the cooler 623.

In the configuration including the two-stage cooler 623, (1) the outer peripheral wall WA1 side of the first-stage cooler 623, (2) between the first-stage and second-stage coolers 623, and (3) the side of the second-stage cooler 623 opposite to the outer peripheral wall are portions where electric components to be cooled are arranged, and the cooling performance of the portions is (2), (1), and (3) in order from high to low. That is, the cooling performance is highest at a portion sandwiched between the two coolers 623, and the cooling performance is higher at a portion adjacent to one of the coolers 623, closer to the outer peripheral wall WA1 (cooling water passage 545). In view of this, in the configuration shown in fig. 61 (a) and (b), the switches 601 and 602 are disposed between (2) the first-stage and second-stage coolers 623, the capacitor 604 is disposed on the outer peripheral wall WA1 side of (1) the first-stage cooler 623, and the drive circuit 603 is disposed on the opposite side of (3) the outer peripheral wall of the second-stage cooler 623. In addition, although not shown, the driver circuit 603 and the capacitor 604 may be configured in reverse.

In either case, inside the module case 611, the switches 601 and 602 and the drive circuit 603, the switches 601 and 602, and the capacitor 604 are electrically connected by the wiring 612, respectively. In addition, since the switches 601 and 602 are located between the driver circuit 603 and the capacitor 604, the wiring 612 extending from the switches 601 and 602 toward the driver circuit 603 and the wiring 612 extending from the switches 601 and 602 toward the capacitor 604 are in a relationship extending in opposite directions to each other.

As shown in fig. 61 (b), the pair of pipe portions 621 and 622 are arranged in the circumferential direction, that is, on the upstream side and the downstream side of the cooling water passage 545, and the cooling water flows into the cooler 623 from the pipe portion 621 on the upstream side and then flows out from the pipe portion 622 on the downstream side and on the downstream side. In order to promote the flow of the cooling water into the cooling device, it is preferable that a restricting portion 624 for restricting the flow of the cooling water is provided in the cooling water passage 545 at a position between the inflow-side piping portion 621 and the outflow-side piping portion 621 as viewed in the circumferential direction. The restricting portion 624 is preferably a blocking portion that blocks the cooling water passage 545 or a throttling portion that reduces the passage area of the cooling water passage 545.

Fig. 62 shows another cooling structure of the switch module 532A. Fig. 62 (a) is a longitudinal sectional view showing a sectional structure of the switch module 532A in a direction crossing the outer peripheral wall WA1, and fig. 62 (B) is a sectional view taken along line 62B-62B of fig. 62 (a).

In the configuration of fig. 62 (a) and (b), the configuration of the pair of pipe portions 621 and 622 in the cooling device is different from the configuration of fig. 61 (a) and (b), and the pair of pipe portions 621 and 622 are arranged in the axial direction. As shown in fig. 62 (c), the passage portion of the cooling water passage 545, which communicates with the inflow-side pipe portion 621, and the passage portion of the cooling water passage 545, which communicates with the outflow-side pipe portion 622, are provided separately in the axial direction, and the passage portions communicate with each other via the pipe portions 621 and 622 and the coolers 623.

As the switch module 532A, the following configuration may be used.

In the structure shown in fig. 63 (a), the cooler 623 is changed from two stages to one stage as compared with the structure of fig. 61 (a). In this case, unlike fig. 61 (a), the portion of the module case 611 where the cooling performance is highest has the highest cooling performance at the portion on the outer peripheral wall WA1 side of both sides in the radial direction of the cooler 623 (both sides in the left-right direction of the figure), and then the cooling performance is reduced in the order of the portion on the opposite side of the outer peripheral wall of the cooler 623 and the portion away from the cooler 623. In view of this, in the configuration shown in fig. 63 a, the switches 601 and 602 are disposed at the outer peripheral wall WA1 side of both sides (both sides in the left-right direction in the figure) in the radial direction of the cooler 623, the capacitor 604 is disposed at the opposite side of the outer peripheral wall of the cooler 623, and the drive circuit 603 is disposed at a position distant from the cooler 623.

In the switch module 532A, the switches 601 and 602, the driver circuit 603, and the capacitor 604 of one phase may be accommodated in the module case 611. For example, any one of the switches 601 and 602, the driver circuit 603, and the capacitor 604 of one phase may be accommodated in the module case 611.

In fig. 63 (b), a pair of pipe sections 621 and 622 and a two-stage cooler 623 are provided in a module case 611, switches 601 and 602 are disposed between the first-stage and second-stage coolers 623, and a capacitor 604 or a drive circuit 603 is disposed on the outer peripheral wall WA1 side of the first-stage cooler 623. Further, a semiconductor module may be formed by integrating the switches 601 and 602 and the driver circuit 603, and the semiconductor module and the capacitor 604 may be housed in the module case 611.

In fig. 63 (b), in the switch module 532A, it is preferable that a capacitor is disposed on the opposite side of the switches 601 and 602 in at least one of the coolers 623 disposed on both sides of the switches 601 and 602. That is, the capacitor 604 may be disposed only on one of the outer peripheral wall WA1 side of the first-stage cooler 623 and the opposite side of the peripheral wall of the second-stage cooler 623, or the capacitors 604 may be disposed on both sides.

In the present embodiment, only the switch module 532A of the switch module 532A and the capacitor module 532B is configured to introduce the cooling water from the cooling water passage 545 into the module. However, the configuration may be changed such that the cooling water is introduced from the cooling water passage 545 to the two modules 532A and 532B.

Further, the electric modules 532 may be configured to be cooled in a state where the outer surfaces of the electric modules 532 are in direct contact with the cooling water. For example, as shown in fig. 64, the outer surface of the electric module 532 is brought into contact with cooling water by embedding the electric module 532 in the outer peripheral wall WA 1. In this case, a structure in which a part of the electric module 532 is immersed in the cooling water passage 545 or a structure in which the cooling water passage 545 is expanded in the radial direction more than the structure of fig. 58 or the like to immerse the entire electric module 532 in the cooling water passage 545 may be considered. When the electrical module 532 is immersed in the cooling water passage 545, the cooling performance can be further improved by providing fins in the immersed module case 611 (the immersed portion of the module case 611).

The electric module 532 includes a switching module 532A and a capacitor module 532B, and when these two modules are compared, the amount of heat generation differs. In view of this, the arrangement of each electrical module 532 in the inverter housing 531 may also be studied.

For example, as shown in fig. 65, the plurality of switch modules 532A are arranged in the circumferential direction without being dispersed, and are disposed on the upstream side of the cooling water passage 545, that is, on the side close to the inlet passage 571. In this case, the cooling water flowing from the inlet passage 571 is used for cooling the three switch modules 532A first, and then used for cooling the capacitor modules 532B. In fig. 65, the pair of pipe portions 621 and 622 are arranged in line in the axial direction as in (a) and (b) of fig. 62, but the present invention is not limited thereto, and the pair of pipe portions 621 and 622 may be arranged in line in the circumferential direction as in (a) and (b) of fig. 61.

Next, a description will be given of a configuration related to electrical connection between each of the electric modules 532 and the bus bar module 533. Fig. 66 is a sectional view taken along line 66-66 of fig. 49, and fig. 67 is a sectional view taken along line 67-67 of fig. 49. Fig. 68 is a perspective view showing the bus bar module 533 as a single body. Here, a configuration related to electrical connection between each of the electric modules 532 and the bus bar module 533 will be described with reference to the above drawings.

As shown in fig. 66, in the inverter case 531, three switch modules 532A are arranged in a circumferential direction at positions circumferentially adjacent to a protruding portion 573 provided to the inner wall member 542 (i.e., the protruding portion 573 provided with an inlet passage 571 and an outlet passage 572 that communicate with the cooling water passage 545), and six capacitor modules 532B are arranged in a circumferential direction at adjacent positions. As a summary thereof, in the inverter case 531, the inside of the outside peripheral wall WA1 is equally divided into ten (i.e., the number of modules +1) regions in the circumferential direction, nine of the regions are each provided with one electrical module 532, and the remaining one region is provided with the protruding portion 573. The three switch modules 532A are a U-phase module, a V-phase module, and a W-phase module.

As shown in fig. 66, fig. 56, fig. 57, and the like, each electrical module 532 (switch module 532A and capacitor module 532B) has a plurality of module terminals 615 extending from a module case 611. The module terminal 615 is a module input/output terminal for inputting/outputting electric power to/from each of the electric modules 532. The module terminals 615 are disposed in an orientation extending in the axial direction, and more specifically, the module terminals 615 are disposed to extend from the module case 611 toward the inner side (vehicle outer side) of the rotor frame 511 (refer to fig. 51).

The module terminals 615 of each electrical module 532 are connected to the bus bar modules 533, respectively. The number of the module terminals 615 is different between the switch module 532A and the capacitor module 532B, four module terminals 615 are provided in the switch module 532A, and two module terminals 615 are provided in the capacitor module 532B.

In addition, as shown in fig. 68, the bus bar module 533 includes: an annular ring-shaped portion 631; three external connection terminals 632, the external connection terminals 632 extending from the annular portion 631 and being connectable to an external device such as a power supply device or an ECU (electronic control unit); and a winding connection terminal 633, the winding connection terminal 633 being connected to a winding end of each phase of the stator winding 521. The bus bar module 533 corresponds to a "terminal module".

The annular portion 631 is disposed at a position radially inward of the outer peripheral wall WA1 and axially on one side of each of the electric modules 532 in the inverter housing 531. The annular portion 631 includes an annular main body portion molded from an insulating member such as resin, and a plurality of bus bars embedded therein. The plurality of bus bars are connected to the module terminals 615 of the respective electric modules 532, the respective external connection terminals 632, and the respective phase windings of the stator winding 521. The details are described later.

The external connection terminal 632 includes a high-potential-side power terminal 632A and a low-potential-side power terminal 632B connected to the power supply device, and one signal terminal 632C connected to the external ECU. The external connection terminals 632(632A to 632C) are arranged in a row in the circumferential direction and extend in the axial direction on the radially inner side of the annular portion 631. As shown in fig. 51, in a state where the bus bar module 533 is assembled with each of the electric modules 532 in the inverter case 531, one end of the external connection terminal 632 protrudes from the end plate 547 of the boss forming member 543. Specifically, as shown in fig. 56 and 57, an insertion hole 547a is provided in an end plate 547 of a boss forming member 543, a cylindrical grommet 635 is attached to the insertion hole 547a, and an external connection terminal 632 is provided in a state where the grommet 635 is inserted therethrough. Grommet 635 also functions as a hermetic connector.

The winding connection terminal 633 is a terminal connected to a winding end of each phase of the stator winding 521, and is provided to extend radially outward from the annular portion 631. The winding connection terminals 633 include a winding connection terminal 633U connected to an end of the U-phase winding in the stator winding 521, a winding connection terminal 633V connected to an end of the V-phase winding, and a winding connection terminal 633W connected to an end of the W-phase winding. It is preferable to provide a current sensor 634 (see fig. 70) for detecting the current (U-phase current, V-phase current, and W-phase current) flowing through the winding connection terminals 633 and the phase windings.

The current sensor 634 may be disposed outside the electric module 532 at a position around each of the winding connection terminals 633, or may be disposed inside the electric module 532.

Here, the connection between each electric module 532 and the bus bar module 533 will be described in more detail with reference to fig. 69 and 70. Fig. 69 is a plan view of the electric modules 532, and schematically shows an electrical connection state between the electric modules 532 and the bus bar module 533. Fig. 70 is a diagram schematically showing connection between each of the electric modules 532 and the bus bar module 533 in a state where each of the electric modules 532 is arranged in an annular shape. In fig. 69, a path for power transmission is indicated by a solid line, and a path for a signal transmission system is indicated by a dashed-dotted line. Fig. 70 shows only paths for power transmission.

The bus bar module 533 has a first bus bar 641, a second bus bar 642, and a third bus bar 643 as bus bars for power transmission. The first bus bar 641 is connected to the high-potential-side power terminal 632A, and the second bus bar 642 is connected to the low-potential-side power terminal 632B. In addition, the three third bus bars 643 are respectively connected to the winding connection terminals 633W of the U-phase winding connection terminal 633U, V phase winding connection terminal 633V, W phase.

The winding connection terminal 633 and the third bus bar 643 are portions that are likely to generate heat due to the operation of the rotating electric machine 10. Therefore, a terminal block, not shown, may be interposed between the winding connection terminal 633 and the third bus bar 643, and the terminal block may be brought into contact with the inverter case 531 having the cooling water passage 545. Alternatively, the winding connection terminal 633 and the third bus bar 643 may be bent in a crank shape, so that the winding connection terminal 633 and the third bus bar 643 may be brought into contact with the inverter case 531 having the cooling water passage 545.

With this configuration, heat generated by the winding connection terminal 633 and the third bus bar 643 can be dissipated to the cooling water in the cooling water passage 545.

In fig. 70, the first bus bar 641 and the second bus bar 642 are illustrated as circular bus bars, but the bus bars 641 and 642 may not necessarily be connected in a circular shape and may have a substantially C-shape in which a part of the circumferential direction is interrupted. Since each of the winding connection terminals 633U, 633V, and 633W is connected to each of the corresponding switch modules 532A, it may be directly connected to each switch module 532A (actually, the module terminal 615) without passing through the bus module 533.

On the other hand, each switch module 532A has four module terminals 615 including a positive electrode-side terminal, a negative electrode-side terminal, a winding terminal, and a signal terminal. Among them, the positive electrode-side terminal is connected to the first bus bar 641, the negative electrode-side terminal is connected to the second bus bar 642, and the winding terminal is connected to the third bus bar 643.

In addition, the bus bar module 533 has a fourth bus bar 644 as a bus bar of the signal transmission system. The signal terminal of each switch module 532A is connected to the fourth bus bar 644, and the fourth bus bar 644 is connected to the signal terminal 632C.

In the present embodiment, the control signal for each switch module 532A is input from the external ECU via the signal terminal 632C. That is, the switches 601 and 602 in the switch modules 532A are turned on and off by a control signal input through the signal terminal 632C. Therefore, each switch module 532A is configured to be connected to the signal terminal 632C without passing through a control device incorporated in the rotating electric machine. However, the configuration may be modified such that a control device is incorporated in the rotating electric machine and a control signal from the control device is input to each switch module 532A. The above structure is shown in fig. 71.

In the configuration of fig. 71, a control board 651 on which a control device 652 is mounted is provided, and the control device 652 is connected to each switch module 532A. Further, a signal terminal 632C is connected to the control device 652. In this case, the control device 652 receives an instruction signal relating to power running or power generation from, for example, an external ECU that is a host control device, and appropriately turns on and off the switches 601 and 602 of the respective switch modules 532A based on the instruction signal.

In the inverter unit 530, the control board 651 is preferably disposed at a position further toward the vehicle outside (the rear side of the rotor frame 511) than the bus bar module 533. Alternatively, the control board 651 is preferably disposed between each of the electric modules 532 and the end plate 547 of the boss forming member 543. The control board 651 is preferably disposed so as to at least partially overlap each of the electric modules 532 in the axial direction.

Each capacitor module 532B has two module terminals 615 including a positive electrode-side terminal connected to the first bus bar 641 and a negative electrode-side terminal connected to the second bus bar 642.

As shown in fig. 49 and 50, a protruding portion 573 having an inlet passage 571 and an outlet passage 572 for cooling water is provided at a position in the inverter case 531 which is circumferentially aligned with each of the electric modules 532, and an external connection terminal 632 is provided so as to be radially adjacent to the protruding portion 573. In other words, the protruding portions 573 and the external connection terminals 632 are provided at the same angular position in the circumferential direction. In the present embodiment, the external connection terminal 632 is provided at a position radially inward of the protruding portion 573. Further, the water passage port 574 and the external connection terminal 632 are arranged in a radial direction in the end plate 547 of the boss forming member 543 as viewed from the vehicle inside of the inverter case 531 (see fig. 48).

In this case, the protruding portions 573 and the external connection terminals 632 are arranged in the circumferential direction together with the plurality of electric modules 532, whereby the inverter unit 530 and the rotary electric machine 500 can be downsized.

As can be seen from fig. 45 and 47 showing the configuration of the wheel 400, the cooling pipe H2 is connected to the water passage port 574, and the harness H1 is connected to the external connection terminal 632, and in this state, the harness H1 and the cooling pipe H2 are accommodated in the accommodating duct 440.

In the above configuration, three switch modules 532A are arranged in a row in the circumferential direction near the external connection terminals 632 in the inverter housing 531, and six capacitor modules 532B are arranged in a row in the circumferential direction near the switch modules, but the configuration may be changed. For example, the three switch modules 532A may be arranged at a position farthest from the external connection terminals 632, that is, at a position on the opposite side of the rotation shaft 501. The switching modules 532A may be arranged in a distributed manner such that the capacitor modules 532B are arranged adjacent to each other on both sides of the switching modules 532A.

If the switch modules 532A are disposed at the position farthest from the external connection terminal 632, that is, at the opposite side with respect to the rotation shaft 501, it is possible to suppress malfunction or the like due to mutual inductance between the external connection terminal 632 and the switch modules 532A.

Next, a description will be given of a configuration of the resolver 660 provided as the rotation angle sensor.

As shown in fig. 49 to 51, the inverter housing 531 is provided with a resolver 660 that detects the electrical angle θ of the rotating electric machine 500. Resolver 660 is an electromagnetic induction type sensor, and includes a resolver rotor 661 fixed to rotation shaft 501; and a resolver stator 662 disposed to face the resolver rotor 661 radially outward. The resolver rotor 661 is formed in a circular plate shape and is coaxially provided on the rotary shaft 501 with the rotary shaft 501 inserted therethrough. The resolver stator 662 includes an annular stator core 663 and a stator coil 664 wound around a plurality of teeth formed in the stator core 663. The stator coil 664 includes an excitation coil of one phase and an output coil of two phases.

The exciting coil of the stator coil 664 is excited by a sine-wave-shaped excitation signal, and magnetic fluxes generated in the exciting coil by the excitation signal are interlinked with the pair of output coils. At this time, since the relative arrangement relationship between the excitation coil and the pair of output coils periodically changes according to the rotation angle of the resolver rotor 661 (i.e., the rotation angle of the rotary shaft 501), the magnetic flux interlinking between the pair of output coils periodically changes. In the present embodiment, the pair of output coils and the exciting coil are arranged such that the phases of the voltages generated by each of the pair of output coils are shifted from each other by pi/2. Thus, the output voltage of each of the pair of output coils is a modulated wave obtained by modulating the excitation signal with the modulation waves sin θ and cos θ, respectively. More specifically, when the excitation signal is "sin Ω t", the modulated waves are "sin θ × sin Ω t" and "cos θ × sin Ω t", respectively.

Parser 660 has a parser digitizer. The resolver-to-digital converter calculates an electrical angle θ from detection based on the generated modulated wave and the excitation signal. For example, the resolver 660 is connected to the signal terminal 632C, and outputs the calculation result of the resolver digital converter to an external device via the signal terminal 632C. In addition, when the control device is incorporated in the rotating electric machine 500, the calculation result of the resolver-to-digital converter is input to the control device.

Here, an assembly structure of the resolver 660 in the inverter case 531 will be described.

As shown in fig. 49 and 51, the boss portion 548 of the boss forming member 543 constituting the inverter housing 531 has a hollow cylindrical shape, and a protruding portion 548a extending in a direction orthogonal to the axial direction is formed on the inner peripheral side of the boss portion 548. Then, the resolver stator 662 is fixed by a screw or the like in a state of being in contact with the protruding portion 548a in the axial direction. In the boss portion 548, a bearing 560 is provided on one side in the axial direction with respect to the projecting portion 548a, and a resolver 660 is coaxially provided on the other side.

In addition, a protruding portion 548a is provided on one side of the resolver 660 in the axial direction in the hollow portion of the boss portion 548, and a disk-ring-shaped housing cover 666 that closes the housing space of the resolver 660 is attached to the other side. The housing cover 666 is made of an electrically conductive material such as Carbon Fiber Reinforced Plastic (CFRP). A hole 666a through which the rotary shaft 501 is inserted is formed in the center of the housing cover 666. A seal 667 is provided in the hole 666a, and the seal 667 seals a gap between the outer peripheral surface of the rotary shaft 501 and the hole 666 a. The resolver housing is closed by a seal 667. The seal 667 is preferably a sliding seal made of, for example, a resin material.

The space for accommodating the resolver 660 is a space surrounded by the annular boss portion 548 of the boss forming member 543 and axially sandwiched by the bearing 560 and the housing cover 666, and the resolver 660 is surrounded by a conductive material. This can suppress the influence of electromagnetic noise on resolver 660.

As described above, the inverter housing 531 has the outer peripheral wall WA1 and the inner peripheral wall WA2 (see fig. 57) of the double layers, the stator 520 is disposed outside the double-layer peripheral wall (outside the outer peripheral wall WA 1), the electric module 532 is disposed between the double-layer peripheral walls (between the outer peripheral walls WA1 and WA 2), and the resolver 660 is disposed inside the double-layer peripheral wall (inside the inner peripheral wall WA 2). Since the inverter case 531 is a conductive member, the stator 520 and the resolver 660 are disposed with a conductive partition wall (particularly, a double-layer conductive partition wall in the present embodiment) interposed therebetween, and the occurrence of magnetic interference between the stator 520 side (magnetic path side) and the resolver 660 can be appropriately suppressed.

Next, the rotor cover 670 provided on the open end side of the rotor frame 511 will be described.

As shown in fig. 49 and 51, the rotor frame 511 is open at one axial side, and a rotor cover 670, which is a substantially circular annular plate, is attached to an open end thereof. The rotor cover 670 is preferably fixed to the rotor frame 511 by any bonding method such as welding, adhesion, or screw fastening. It is preferable that the rotor cover 670 has a portion sized smaller than the inner circumference of the rotor frame 511 to be able to suppress the magnet unit 512 from moving in the axial direction. The rotor cover 670 has an outer diameter corresponding to the outer diameter of the rotor frame 511, and an inner diameter slightly larger than the outer diameter of the inverter housing 531. Further, the outer diameter dimension of the inverter housing 531 is the same as the inner diameter dimension of the stator 520.

As described above, the stator 520 is fixed to the radially outer side of the inverter housing 531, and the inverter housing 531 protrudes in the axial direction with respect to the stator 520 in the joint portion where the stator 520 and the inverter housing 531 are joined to each other. Then, the rotor cover 670 is installed to surround the protruding portion of the inverter housing 531. In this case, a seal 671 for closing a gap between an end surface on the inner peripheral side of the rotor cover 670 and the outer peripheral surface of the inverter housing 531 is provided. The seal 671 closes the housing space of the magnet unit 512 and the stator 520. The seal 671 is preferably a sliding seal made of, for example, a resin material.

According to the present embodiment described in detail above, the following excellent effects can be obtained.

In the rotating electric machine 500, an outer peripheral wall WA1 of the inverter housing 531 is disposed radially inward of a magnetic circuit portion constituted by the magnet unit 512 and the stator winding 521, and a cooling water passage 545 is formed in the outer peripheral wall WA 1. Further, a plurality of electrical modules 532 are arranged in the circumferential direction along the outer peripheral wall WA1 radially inward of the outer peripheral wall WA 1. As a result, the magnetic circuit portion, the cooling water passage 545, and the power converter can be arranged in a manner stacked in the radial direction of the rotating electrical machine 500, and the dimensions in the axial direction can be reduced, and efficient component arrangement can be achieved. In addition, the plurality of electrical modules 532 constituting the power converter can be efficiently cooled. As a result, the rotating electric machine 500 can be made more efficient and smaller.

The electric module 532 (the switch module 532A and the capacitor module 532B) including heat generating components such as semiconductor switching elements and capacitors is provided in a state of being in contact with the inner peripheral surface of the outer peripheral wall WA 1. Thereby, the heat in each electrical module 532 is transferred to the outside peripheral wall WA1, and the electrical module 532 is appropriately cooled by the heat exchange at the outside peripheral wall WA 1.

In the switch module 532A, the coolers 623 are arranged on both sides with the switches 601 and 602 therebetween, and the capacitor 604 is arranged on the opposite side of the switches 601 and 602 at least one of the coolers 623 on both sides of the switches 601 and 602. This can improve the cooling performance of the switches 601 and 602 and also improve the cooling performance of the capacitor 604.

In the switch module 532A, the coolers 623 are arranged on both sides with the switches 601 and 602 therebetween, the driver circuit 603 is arranged on the side opposite to the switches 601 and 602 in one of the coolers 623 on both sides of the switches 601 and 602, and the capacitor 604 is arranged on the side opposite to the switches 601 and 602 in the other cooler 623. This can improve cooling performance for the switches 601 and 602, and can improve cooling performance for the driver circuit 603 and the capacitor 604.

For example, in the switching module 532A, cooling water is made to flow into the module from the cooling water passage 545, and the semiconductor switching elements and the like are cooled by the cooling water. In this case, the switch module 532A is cooled by heat exchange with the cooling water inside the module in addition to heat exchange with the cooling water in the outside peripheral wall WA 1. This can improve the cooling effect of the switch module 532A.

In a cooling system in which cooling water flows into the cooling water passage 545 from an external circulation path 575, the switch module 532A is disposed on the upstream side of the inlet passage 571 of the cooling water passage 545, and the capacitor module 532B is disposed on the downstream side of the switch module 532A. In this case, if it is assumed that the temperature of the cooling water flowing through the cooling water passage 545 is lower on the upstream side, the configuration can be realized in which the switch module 532A is cooled preferentially.

The interval between the circumferentially adjacent electric modules is enlarged at a portion, and a projection 573 having an inlet passage 571 and an outlet passage 572 is provided at a portion of the enlarged interval (second interval INT 2). Thus, the inlet passage 571 and the outlet passage 572 of the cooling water passage 545 can be appropriately formed in the radially inner portion of the outer peripheral wall WA 1. That is, in order to improve the cooling performance, it is necessary to secure the flow rate of the refrigerant, and for this reason, it is conceivable to increase the opening areas of the inlet passage 571 and the outlet passage 572. In this regard, by providing the protruding portion 573 by partially enlarging the interval between the electrical modules as described above, the inlet passage 571 and the outlet passage 572 having desired sizes can be appropriately formed.

The external connection terminals 632 of the bus bar module 533 are arranged at positions radially aligned with the projections 573 in the radially inner side of the outer peripheral wall WA 1. That is, the external connection terminals 632 are arranged in the portions where the interval between the circumferentially adjacent electric modules is widened (the portions corresponding to the second interval INT 2) together with the protruding portions 573. This allows the external connection terminals 632 to be appropriately arranged while avoiding interference with the electric modules 532.

In the outer rotor type rotating electric machine 500, the stator 520 is fixed to the radially outer side of the outer peripheral wall WA1, and a plurality of electric modules 532 are arranged radially inward. Thus, heat of the stator 520 is transferred from radially outside the outer peripheral wall WA1 to the outer peripheral wall WA1, and heat of the electric module 532 is transferred from radially inside the outer peripheral wall WA1 to the outer peripheral wall WA 1. In this case, the stator 520 and the electric module 532 can be simultaneously cooled by the cooling water flowing through the cooling water passage 545, and thus the heat of the heat generating member in the rotating electrical machine 500 can be efficiently released.

The radially inner electric module 532 and the radially outer stator winding 521, which sandwich the outer peripheral wall WA1, are electrically connected by the winding connection terminals 633 of the bus bar module 533. Further, in this case, the winding connection terminals 633 are configured to be provided at positions axially separated from the cooling water passage 545. Thus, even if the cooling water passage 545 is formed in the outer peripheral wall WA1 in an annular shape, that is, the outer and inner sides of the outer peripheral wall WA1 are partitioned by the cooling water passage 545, the electric module 532 and the stator winding 521 can be appropriately connected.

In the rotating electrical machine 500 according to the present embodiment, the reduction or elimination of the teeth (cores) between the respective conductive wires 523 arranged in the circumferential direction in the stator 520 can suppress torque limitation due to magnetic saturation occurring between the respective conductive wires 523, and can suppress torque reduction by flattening and thinning the conductive wires 523. In this case, even if the outer diameter of the rotating electric machine 500 is the same, the radially inner region of the magnetic circuit portion can be expanded by thinning the stator 520, and the outer circumferential wall WA1 having the cooling water passage 545 and the plurality of electric modules 532 disposed radially inward of the outer circumferential wall WA1 can be appropriately arranged using the inner region.

In the rotating electrical machine 500 of the present embodiment, the magnet flux is concentrated on the d-axis side in the magnet unit 512, so that the magnet flux at the d-axis can be increased, and the torque can be increased accordingly. In this case, the radially inner region of the magnetic circuit portion can be enlarged as the thickness dimension in the radial direction of the magnet unit 512 can be reduced (thinned), and the outer circumferential wall WA1 having the cooling water passage 545 and the plurality of electric modules 532 disposed radially inward of the outer circumferential wall WA1 can be appropriately arranged using the inner region.

In addition, not only the magnetic circuit portion, the outer peripheral wall WA1, and the plurality of electric modules 532, but also the bearing 560 and the resolver 660 can be similarly arranged appropriately in the radial direction.

The wheel 400 using the rotary electric machine 500 as an in-wheel motor is attached to the vehicle body via a base plate 405 fixed to the inverter housing 531 and an attachment mechanism such as a suspension device. Here, since miniaturization is achieved in the rotating electrical machine 500, space can be saved even if assembly to the vehicle body is assumed. Therefore, a configuration advantageous in terms of enlarging the installation area of the power supply device such as a battery or enlarging the vehicle interior space can be realized in the vehicle.

Next, a modified example of the in-wheel motor will be described.

(modification of in-wheel Motor 1)

In the rotating electric machine 500, the electric module 532 and the bus bar module 533 are arranged radially inward of the outer peripheral wall WA1 of the inverter unit 530, and the electric module 532 and the bus bar module 533 and the stator 520 are arranged radially inward and outward of the outer peripheral wall WA 1. In this configuration, the position of the bus bar module 533 relative to the electric module 532 can be arbitrarily set. When the respective phase windings of the stator winding 521 and the bus bar module 533 are connected to each other while crossing the outer peripheral wall WA1 in the radial direction, the position at which the winding connection wire (for example, the winding connection terminal 633) used for the connection can be arbitrarily set.

That is, as the position of the bus bar module 533 with respect to the electric module 532, the following configuration is considered: (α 1) the bus bar module 533 is provided at a position axially further to the vehicle outer side than the electric module 532, that is, the rear side on the rotor frame 511 side;

(α 2) the bus bar module 533 is disposed axially further toward the vehicle inside than the electric module 532, that is, toward the front side of the rotor frame 511.

In addition, as a position for guiding the winding connection line, the following configuration is considered:

(β 1) guiding the winding connection line on the vehicle outer side in the axial direction, that is, on the inner side of the rotor frame 511;

(β 2) the winding connection line is guided on the vehicle inner side in the axial direction, that is, on the near side of the rotor frame 511.

Hereinafter, four configuration examples relating to the arrangement of the electric module 532, the bus bar module 533, and the winding connection line will be described using (a) to (d) of fig. 72. Fig. 72 (a) to (d) are vertical sectional views showing the structure of the rotating electric machine 500 in a simplified manner, and in the drawings, the structures already described are denoted by the same reference numerals. The winding connection line 637 is an electric wiring for connecting each phase winding of the stator winding 521 to the bus bar module 533, and corresponds to, for example, the winding connection terminal 633 described above.

In the configuration of fig. 72 (a), the above-described (α 1) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above-described (β 1) is adopted as the position of the lead winding connection line 637. That is, the electric module 532 and the bus bar module 533, and the stator winding 521 and the bus bar module 533 are connected on the vehicle outer side (the back side of the rotor frame 511). This corresponds to the structure shown in fig. 49.

According to this configuration, the cooling water passage 545 can be provided in the outer peripheral wall WA1 without concern for interference with the winding connection line 637. Further, the winding connection lines 637 connecting the stator windings 521 and the bus bar modules 533 can be simply implemented.

In the configuration of fig. 72 (b), the above-described (α 1) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above-described (β 2) is adopted as the position of guiding the winding connection line 637. That is, the electric module 532 and the bus bar module 533 are connected on the vehicle outside (the back side of the rotor frame 511), and the stator winding 521 and the bus bar module 533 are connected on the vehicle inside (the front side of the rotor frame 511).

According to this configuration, the cooling water passage 545 can be provided in the outer peripheral wall WA1 without concern for interference with the winding connection line 637.

In the configuration of fig. 72 (c), the above-described (α 2) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above-described (β 1) is adopted as the position of guiding the winding connection line 637. That is, the electric module 532 and the bus bar module 533 are connected on the vehicle inside (the front side of the rotor frame 511), and the stator winding 521 and the bus bar module 533 are connected on the vehicle outside (the back side of the rotor frame 511).

In the configuration of fig. 72 (d), the above-described (α 2) is adopted as the position of the bus bar module 533 with respect to the electric module 532, and the above-described (β 2) is adopted as the position of guiding the winding connection line 637. That is, the electric module 532 and the bus bar module 533, and the stator winding 521 and the bus bar module 533 are connected on the vehicle inside (the front side of the rotor frame 511).

According to the configurations of fig. 72 (c) and 72 (d), the bus bar module 533 is disposed on the vehicle inner side (the front side of the rotor frame 511), and thus wiring is considered to be facilitated if an electric component such as a fan motor is added. Further, the bus bar module 533 can be brought close to the resolver 660 disposed on the vehicle inner side of the bearing, and it is considered that the resolver 660 can be easily wired.

(modification of in-wheel Motor 2)

A modified example of the mounting structure of the resolver rotor 661 will be described below. That is, the rotary shaft 501, the rotor frame 511, and the inner ring 561 of the bearing 560 are rotating bodies that rotate integrally, and a modification of the mounting structure of the resolver rotor 661 to the rotating bodies will be described below.

Fig. 73 (a) to (c) are configuration diagrams showing an example of a mounting configuration of the resolver rotor 661 to the rotating body. In either configuration, the resolver 660 is provided in a sealed space surrounded by the rotor frame 511, the inverter housing 531, and the like and shielded from splash water, splash mud, and the like from the outside. In fig. 73 (a) to 73 (c), the bearing 560 is configured similarly to fig. 49. In fig. 73 (b) and 73 (c), the bearing 560 is configured differently from fig. 49 and is disposed at a position distant from the end plate 514 of the rotor frame 511. In the above figures, two mounting positions of the resolver rotor 661 are illustrated. Although the resolver stator 662 is not shown, for example, the sleeve portion 548 of the sleeve forming member 543 may be extended to the outer peripheral side of the resolver rotor 661 or the vicinity thereof, and the resolver stator 662 may be fixed to the sleeve portion 548.

In the structure of fig. 73 (a), a resolver rotor 661 is attached to an inner ring 561 of the bearing 560. Specifically, the resolver rotor 661 is provided on an axial end surface of the flange 561b of the inner ring 561 or on an axial end surface of the cylindrical portion 561a of the inner ring 561.

In the configuration of fig. 73 (b), the resolver rotor 661 is attached to the rotor frame 511. Specifically, the resolver rotor 661 is provided on an inner surface of the end plate 514 in the rotor frame 511. Alternatively, when the rotor frame 511 is configured to have a cylindrical portion 515 extending from the inner peripheral edge portion of the end plate 514 along the rotation shaft 501, the resolver rotor 661 is provided on the outer peripheral surface of the cylindrical portion 515 of the rotor frame 511. In the latter case, the resolver rotor 661 is disposed between the end plate 514 of the rotor frame 511 and the bearing 560.

In the configuration of fig. 73 (c), a resolver rotor 661 is attached to the rotary shaft 501. Specifically, the resolver rotor 661 is provided between the end plate 514 of the rotor frame 511 and the bearing 560 on the rotary shaft 501, or is disposed on the opposite side of the rotary shaft 501 from the rotor frame 511 via the bearing 560.

(modification of in-wheel Motor 3)

Hereinafter, a modification of the inverter housing 531 and the rotor cover 670 will be described with reference to fig. 74. Fig. 74 (a) and 74 (b) are vertical sectional views showing the structure of the rotating electric machine 500 in a simplified manner, and in the drawings, the structures already described are denoted by the same reference numerals. The structure shown in fig. 74 (a) substantially corresponds to the structure described in fig. 49 and the like, and the structure shown in fig. 74 (b) corresponds to a structure in which a part of the structure shown in fig. 74 (a) is changed.

In the structure shown in fig. 74 (a), a rotor cover 670 fixed to the open end of the rotor frame 511 is provided so as to surround the outer peripheral wall WA1 of the inverter housing 531. That is, the inner diameter side end surface of the rotor cover 670 faces the outer peripheral surface of the outer peripheral wall WA1, and a seal 671 is provided therebetween. Further, a housing cover 666 is mounted in a hollow portion of the boss portion 548 of the inverter housing 531, and a seal 667 is provided between this housing cover 666 and the rotary shaft 501. The external connection terminals 632 constituting the bus bar module 533 penetrate the inverter housing 531 and extend to the vehicle inside (lower side in the drawing).

Further, an inlet passage 571 and an outlet passage 572 that communicate with the cooling water passage 545 are formed in the inverter case 531, and a water passage port 574 including a passage end of the inlet passage 571 and the outlet passage 572 is formed.

In contrast, in the configuration shown in fig. 74 b, an annular projection 681 extending to the projecting side (vehicle interior side) of the rotary shaft 501 is formed on the inverter housing 531 (specifically, the boss forming member 543), and the rotor cover 670 is provided so as to surround the projection 681 of the inverter housing 531. That is, the end surface of the rotor cover 670 on the inner diameter side faces the outer peripheral surface of the projection 681, and the seal 671 is provided therebetween. In addition, the external connection terminal 632 constituting the bus bar module 533 penetrates the boss portion 548 of the inverter housing 531 and extends to the hollow area of the boss portion 548, and penetrates the housing cover 666 and extends to the vehicle inside (lower side in the drawing).

Further, an inlet passage 571 and an outlet passage 572 that communicate with the cooling water passage 545 are formed in the inverter housing 531, and the inlet passage 571 and the outlet passage 572 extend to a hollow region of the boss portion 548 and further extend to a position (lower side in the drawing) on the vehicle inner side than the housing cover 666 via the relay pipe 682. In this structure, the piping portion extending from the housing cover 666 to the vehicle inside is a waterway port 574.

According to the respective configurations of fig. 74 (a) and 74 (b), the rotor frame 511 and the rotor cover 670 can be appropriately rotated with respect to the inverter case 531 while maintaining the sealing property of the inner space of the rotor frame 511 and the rotor cover 670.

In particular, according to the structure of fig. 74 (b), the inner diameter of the rotor cover 670 is smaller than that of the structure of fig. 74 (a). Therefore, the inverter housing 531 and the rotor cover 670 are provided in two layers in the axial direction at a position on the vehicle inner side of the electrical module 532, and it is possible to suppress a problem due to electromagnetic noise that may be generated by the electrical module 532. In addition, by reducing the inner diameter of the rotor cover 670, the sliding radius of the seal 671 becomes small, so that mechanical loss in the rotary sliding portion can be suppressed.

(modification of in-wheel Motor 4)

A modified example of the stator winding 521 will be described below. Fig. 75 shows a modification example related to the stator winding 521.

As shown in fig. 75, the stator winding 521 uses a wire material having a rectangular cross section, and the long sides of the wire material are wound in a wave winding manner in a direction extending in the circumferential direction. In this case, the wires 523 of the respective phases in the stator winding 521, which become the coil side portions, are arranged at a predetermined pitch interval for each phase, and are connected to each other at the coil side end portions. The end faces of the circumferentially adjacent conductive wires 523 in the coil side portion in the circumferential direction abut against each other or are arranged close to each other with a minute interval.

Further, in the stator winding 521, the wire material is bent in the radial direction for each phase at the coil edge end portion. In more detail, the stator winding 521 (wire material) is bent radially inward at a position different for each phase in the axial direction, thereby avoiding interference of the windings of the respective phases of the U-phase, the V-phase, and the W-phase with each other. In the illustrated structure, the wire material is bent at a right angle radially inward for each phase, with only a difference in thickness of the wire material between the windings of the respective phases. In each of the conductive lines 523 arranged in the circumferential direction, the length dimension between both ends in the axial direction is preferably the same in each of the conductive lines 523.

When stator 520 is manufactured by assembling stator core 522 to stator winding 521, it is preferable that a part of the stator winding 521 in an annular shape is cut off so as not to be connected (that is, stator winding 521 is formed in a substantially C-shape), and after stator core 522 is assembled to the inner circumferential side of stator winding 521, the cut-off parts are connected to each other so as to form stator winding 521 in an annular shape.

In addition to the above, the stator core 522 may be divided into a plurality of pieces (for example, three or more pieces) in the circumferential direction, and the iron core pieces divided into a plurality of pieces may be assembled on the inner circumferential side of the stator winding 521 formed in an annular shape.

(other modification example)

For example, as shown in fig. 50, in the rotary electric machine 500, the inlet passage 571 and the outlet passage 572 of the cooling water passage 545 are provided at one point, but the inlet passage 571 and the outlet passage 572 may be provided at different positions in the circumferential direction by changing the configuration. For example, the inlet passage 571 and the outlet passage 572 may be provided at positions that are different by 180 degrees in the circumferential direction, or at least one of the inlet passage 571 and the outlet passage 572 may be provided in plural.

In the wheel 400 of the above embodiment, the rotary shaft 501 is configured to protrude to one side in the axial direction of the rotary electric machine 500, but it may be configured to protrude to both sides in the axial direction by changing the configuration. Thus, for example, a suitable configuration can be realized in a vehicle in which at least one of the front and rear of the vehicle is one wheel.

As the rotating electrical machine 500 for the wheel 400, an inner rotor type rotating electrical machine may also be used.

(modification 15)

Next, a rotary electric machine 700 according to this modification will be described. The rotating electrical machine 700 is used as a drive unit of a vehicle. Fig. 76 to 78 show an outline of the rotary electric machine 700. Fig. 76 is a perspective view showing the entire rotary electric machine 700, fig. 77 is a vertical sectional view of the rotary electric machine 700, and fig. 78 is an exploded sectional view showing the components of the rotary electric machine 700 in an exploded manner.

The rotating electric machine 700 is an outer rotor type surface magnet type rotating electric machine. The rotating electric machine 700 generally includes a rotating electric machine main body including the rotor 710, the stator 730, the inner unit 770, and the bus bar module 810, and a housing 831 and a cover 832 provided so as to surround the rotating electric machine main body. The above-described members are arranged coaxially with respect to a rotating shaft 701 integrally provided in the rotor 710, and are assembled in the axial direction in a predetermined order, thereby configuring the rotating electric machine 700. The rotor 710 is supported by a pair of bearings 791, 792 provided radially inside the inner unit 770 in a cantilever manner, and is rotatable in this state. A coupling shaft 705 fixed to an axle, a wheel, or the like of the vehicle is integrally provided on the rotary shaft 701.

In the rotating electric machine 700, the rotor 710 and the stator 730 are each cylindrical and arranged to face each other in the radial direction with an air gap interposed therebetween. The rotor 710 rotates integrally with the rotating shaft 701, whereby the rotor 710 rotates radially outward of the stator 730. The rotor 710 corresponds to an "exciting element", and the stator 730 corresponds to an "armature".

As shown in fig. 79, the rotor 710 includes a substantially cylindrical rotor frame 711 and an annular magnet unit 712 fixed to the rotor frame 711. The rotor frame 711 includes an end plate portion 713 and a cylindrical portion 714 extending in the axial direction from the outer peripheral portion of the end plate portion 713. The end plate portion 713 is formed with a through hole 713a, and the rotary shaft 701 is fixed to the end plate portion 713 with a fastener 715 such as a bolt in a state inserted through the through hole 713 a. The rotary shaft 701 has a flange 702 extending in a direction intersecting with (orthogonal to) the axial direction at a portion to which the rotor frame 711 is fixed, and the rotor frame 711 is fixed to the rotary shaft 701 in a state where the flange 702 is surface-bonded to the end plate portion 713.

The magnet unit 712 has a cylindrical magnet holder 721, a magnet 722 fixed to an inner peripheral surface of the magnet holder 721, and end plates 723 fixed to the opposite side of the rotor frame 711 on both axial sides of the magnet 722. The magnet holder 721 has the same length dimension in the axial direction as the magnet 722. The magnet 722 is provided in a state of being surrounded by the magnet holder 721 from the radial outside. Further, the magnet holder 721 and the magnet 722 are fixed in a state where one end side of both ends in the axial direction abuts against the rotor frame 711, and the other end side is fixed in a state where it abuts against the end plate 723.

The rotor frame 711, the magnet holder 721, and the end plate 723 are each made of aluminum or nonmagnetic stainless steel (e.g., SUS304) as a nonmagnetic body. The members are preferably made of light metal such as aluminum, but may be made of synthetic resin. The above-mentioned members are preferably joined by bonding or welding.

Fig. 80 is a partial sectional view showing a sectional structure of the magnet unit 712. In fig. 80, the easy axis of the magnet 722 is indicated by an arrow.

In the magnet unit 712, the magnets 722 are arranged in such a manner as to alternately change polarity in the circumferential direction of the rotor 710. Thus, the magnet 722 has a plurality of magnetic poles in the circumferential direction. The magnet 722 is a permanent magnet having polar anisotropy, and is configured by using a sintered neodymium magnet having an intrinsic coercive force of 400[ kA/m ] or more and a residual magnetic flux density Br of 1.0[ T ] or more.

The magnet 722 is disposed as one magnet between d-axes, which are the centers of each of two magnetic poles adjacent in the circumferential direction. That is, the magnet 722 has one magnetic pole as one magnet, and the center in the circumferential direction thereof is the q-axis. The magnet 722 has a magnetic flux transmission surface 724 on the radially inner circumferential surface thereof, through which magnetic flux is transmitted. In the magnet 722, the directions of the easy magnetization axes are different between the d-axis side (portion close to the d-axis) where the direction of the easy magnetization axis is parallel to the d-axis and the q-axis side (portion close to the q-axis) where the direction of the easy magnetization axis is orthogonal to the q-axis. In this case, a magnet magnetic path of an arc shape is formed in accordance with the direction of the magnetization easy axis. In short, the magnet unit 722 is configured to be oriented such that the direction of the magnetization easy axis is more parallel to the d axis at the magnetic pole center, i.e., the d axis side, than the magnetic pole boundary, i.e., the q axis side.

According to the respective magnets 722 arranged in the circumferential direction, the magnet magnetic flux at the d-axis is enhanced, and the magnetic flux variation in the vicinity of the q-axis is suppressed. This makes it possible to desirably realize the magnet 722 in which the surface magnetic flux change from the q axis to the d axis is relaxed in each magnetic pole. Instead of the configuration in which the circumferential center is the q-axis, the magnet 722 may be configured such that the circumferential center is the d-axis. In addition, instead of using the same number of magnets as the number of magnetic poles, the magnet 722 may be configured to use a ring-shaped magnet.

The magnet 722 preferably has the following structure. In the magnet 722, the arc length of the magnetic flux transfer surface 724 between the d-q axes is larger than the radial thickness of the magnet 722. As shown in fig. 81, in the magnet 722, when a circle whose center point CP is an intersection point between the q-axis and the magnetic flux transmission surface 724 and whose radius is a radial thickness dimension of the magnet 722 is an orientation circle X that defines an easy magnetization axis of the magnet 722, the magnet 722 is configured as a quarter circle including the orientation circle X. That is, in the magnet 722, the arc-shaped easy magnetization axis is provided so as to cross the q-axis, and the strongest magnet magnetic flux is generated by the easy magnetization axis passing through the intersection of the q-axis and the circumferential surface on the opposite side to the magnetic flux transmission surface 724 in the radial direction, that is, the easy magnetization axis passing through the orientation circle X, out of the easy magnetization axes. In this case, the magnet 722 is configured as a quarter circle including the orientation circle X, so that the magnet magnetic flux can be generated while ensuring the length of the magnet magnetic path passing through the d-axis to the length specified by the orientation circle X.

Here, in the magnet 722, if the arc length of the magnetic flux transmission surface 724 between the d-q axes is larger than the radial thickness of the magnet 722, there is a possibility that magnetic flux leakage to the outside in the radial direction of the magnet 722, that is, the opposite side to the stator may occur. However, in the configuration of this example, the magnet holder 721 is made of a non-magnetic body, and the influence of the leakage of magnetic flux can be reduced.

In the magnet 722, a recess 725 is formed in a predetermined range including the d-axis on the outer peripheral surface on the outer side in the radial direction, and a recess 726 is formed in a predetermined range including the q-axis on the inner peripheral surface on the inner side in the radial direction. In this case, the magnet magnetic circuit in the vicinity of the d-axis becomes short on the outer circumferential surface of the magnet 722, and the magnet magnetic circuit in the vicinity of the q-axis becomes short on the inner circumferential surface of the magnet 722, depending on the direction of the easy magnetization axis of the magnet 722. Therefore, it is considered that it is difficult to generate a sufficient magnet magnetic flux in a portion of the magnet 722 having a short magnetic path length, and the magnet is removed in a portion where the magnet magnetic flux is weak.

The magnet holder 721 is disposed radially outward of the respective magnets 722 arranged in the circumferential direction. In addition, the magnet holder 721 may also be provided within a range including between the respective magnets 722 in the circumferential direction and radially inside of the respective magnets 722. That is, the magnet holder 721 may be provided so as to surround the magnet 722. In the case where the magnet holder 721 has a radially outer portion and a radially inner portion of each magnet 722, the strength of the radially outer portion is preferably higher than the strength of the radially inner portion.

The magnet holder 721 has convex portions 727, which convex portions 727 enter the concave portions 725 of the magnet 722. In this case, since the concave portion 725 of the magnet 722 engages with the convex portion 727 of the magnet holder 721, positional deviation of the magnet 722 in the circumferential direction is suppressed. That is, the convex portions 727 of the magnet holder 721 function as rotation stoppers of the magnet 722. In addition, in the case where the magnet holder 721 has a portion located radially inward (on the stator 730 side) of the magnet 722, a convex portion that enters the concave portion 726 of the magnet 722 may be provided in the portion.

Next, the structure of the stator 730 will be described.

Stator 730 has stator winding 731 and stator core 732. Fig. 82 is a perspective view showing the structure of the stator 730, fig. 83 is a perspective view showing the stator winding 731 and the stator core 732 in an exploded manner, fig. 84 is a perspective view showing only the structure corresponding to the U-phase winding in the phase winding of each phase, and fig. 85 is a vertical sectional view of the stator 730.

The stator core 732 is formed as a core segment laminate in which a plurality of core segments 732a made of electromagnetic steel plates as magnetic bodies are used and the plurality of core segments 732a are laminated in the axial direction, and has a cylindrical shape having a predetermined thickness in the radial direction. Stator winding 731 is assembled on the radially outer side of stator core 732, which is the rotor 710 side. The outer peripheral surface of stator core 732 has a curved surface shape without unevenness. The stator core 732 functions as a back yoke. The stator core 732 is formed by laminating a plurality of core pieces 732a punched out in an annular plate shape in the axial direction, for example. However, stator core 732 having a spiral core structure may also be used. In the stator core 732 having the spiral core structure, a band-shaped core piece is used, and the core pieces are annularly wound and stacked in the axial direction, whereby the cylindrical stator core 732 is formed as a whole.

In stator core 732, end rings 733 are fixed to end faces on both axial sides. The end ring 733 is a positioning member that has a function of holding the stator winding 731 at a predetermined position in the circumferential direction in a state where the stator winding 731 is assembled to the stator core 732. Stator core 732 and end ring 733 are base members 736.

The engagement surface 734 is formed on the outer peripheral surface of the end ring 733 in an inclined direction with respect to a tangent line on a concentric circle concentric with the stator core 732 and the end ring 733. The engagement surface 734 is provided to equally divide the outer peripheral surface of the end ring 733 into a plurality of parts. In this example, the same number of engaging surfaces 734 as the number of lead portions of the coil side portion (linear portions 744 of the coil module 740, which will be described later) arranged in the circumferential direction in the stator winding 731 are provided in the circumferential direction. In this example, since the inclination directions with respect to the tangent line are opposite to each other on the engagement surfaces 734 adjacent in the circumferential direction, a tapered engagement portion is formed on the outer peripheral surface of the end portion ring 733. In this case, a concave portion 735 is formed between the tapered convex portions.

In each of the end rings 733 on both sides in the axial direction, the positions of the projections and recesses in the circumferential direction on one end side and the other end side in the axial direction coincide. That is, the end ring 733 on the one axial end side and the end ring 733 on the other axial end side are fixed to the stator core 732 such that the positions of the convex portions formed by the engagement surface 734 are circumferentially aligned.

The inner diameter of end ring 733 is the same as the inner diameter of stator core 732. The outer diameter of the end ring 733 is the same as the outer diameter of the stator core 732 at the portion having the largest diameter, and is smaller than the outer diameter of the stator core 732 at the portion having the smallest diameter.

The end ring 733 is formed of a nonmagnetic material such as aluminum or copper. The end ring 733 is fixed to the stator core 732 by welding. In addition, the end ring 733 may be mechanically fixed by press-fitting with an insertion pin or a key or by fastening with a bolt. By such mechanical fixation, positional displacement of the end ring 733 with respect to the circumferential direction of the stator core 732 is suppressed.

As shown in fig. 85, the stator 730 has, in the axial direction, a portion corresponding to the coil side CS that is radially opposed to the magnet 722 of the rotor 710, and portions corresponding to the coil side ends CE1, CE2 that are axially outer sides of the coil side CS. In this case, the stator core 732 is provided in a range corresponding to the coil side CS in the axial direction, and the end rings 733 are provided at the coil side end CE1 on one end side and the coil side end CE2 on the other end side in the axial direction, respectively. The coil side end CE1 corresponds to a first coil side end, and the coil side end CE2 corresponds to a second coil side end. Further, a structure of a state where the end ring 733 is engaged with the stator winding 731 will be described later.

The stator winding 731 has a plurality of phase windings, and the phase windings of the respective phases are arranged in a predetermined order in the circumferential direction, and are formed in a cylindrical shape (ring shape). Stator core 732 is assembled to a radially inner side of stator winding 731. In this example, the stator winding 731 has three-phase windings by using U-phase, V-phase, and W-phase windings.

In the stator winding 731, each phase winding of each phase has a plurality of partial windings 741 (see fig. 86), and the partial windings 741 are individually provided as a coil block 740. That is, the coil block 740 is configured such that partial windings 741 of the phase windings of the respective phases are integrally provided. The coil modules 740 of the respective phases are arranged in a predetermined order in the circumferential direction, so that the lead portions of the respective phases are arranged in a predetermined order at the coil side portions of the stator winding 731. Fig. 82 shows the arrangement order of the U-phase, V-phase, and W-phase lead portions at the coil side portions. In fig. 84, only the coil module 740 constituting the U-phase winding among the three-phase windings is drawn out and shown. Although the number of magnetic poles is 24 in this example, the number may be arbitrary.

In the stator winding 731, the partial windings 741 of the coil modules 740 for each phase are connected in parallel or in series to constitute a phase winding for each phase. Fig. 86 is a circuit diagram showing a connection state of a part of windings 741 in each phase winding of three phases. Fig. 86 shows a state in which some of the phase windings 741 of the respective phases are connected in parallel.

As shown in fig. 85, the coil module 740 is assembled to the radially outer side of the stator core 732. The stator winding 731 has a portion corresponding to the coil side CS and portions corresponding to the coil side ends CE1 and CE 2. In this case, the coil module 740 is assembled in a state in which both axial end portions thereof protrude outward in the axial direction of the stator core 732 (i.e., on the coil side end portion side).

The coil modules 740 are formed in a substantially L-shape by bending one of the axial ends in the radial direction, and interference between the coil modules 740 adjacent to each other in the circumferential direction is suppressed by the bending. In this example, the coil module 740 is configured to use a coil module 740A arranged such that a portion on one end side in the axial direction faces radially outward and a coil module 740B arranged such that a portion on one end side in the axial direction faces radially inward. That is, the stator winding 731 is formed using two types of coil modules 740A and 740B. The coil modules 740A and 740B are assembled to the stator core 732 so that the axial directions thereof are opposite to each other.

As shown in fig. 82, in a state where a plurality of coil modules 740 are assembled to the stator core 732, the restricting rings 760 are attached to two axial positions on the radially outer side of the coil modules 740. The confinement rings 760 are confinement members that radially confine the coil modules 740 (the stator windings 731). The confinement ring 760 is, for example, a metal annular ring. A C-ring or a multi-layer ring having both free ends may be used as the confinement ring 760, and the ends of the confinement ring 760 may be connected to each other by welding, bonding, or the like. In this case, the confinement rings 760 preferably have elasticity and are smaller than the diameter of the stator windings 731 in a natural state.

A linear member such as a wire, a string, or a wire rod may be used as the restricting member, and the restricting member may be spirally wound on the outer circumferential side of the stator winding 731. In this case, for example, the string may be impregnated with varnish, and the string may be fixed and reinforced with varnish.

Next, the structure of the coil module 740 will be described in detail.

Here, first, the coil module 740A of the coil modules 740A and 740B will be described. Furthermore, the coil module 740 is a subassembly having a partial winding 741 and a winding holder 742. In the following description, the partial winding 741 of the coil module 740A is also referred to as "partial winding 741A", the winding holder 742 is also referred to as "winding holder 742A", the partial winding 741 of the coil module 740B is also referred to as "partial winding 741B", and the winding holder 742 is also referred to as "winding holder 742B". The partial winding 741A corresponds to a first partial winding, and the partial winding 741B corresponds to a second partial winding.

Fig. 87 (a) is a perspective view of the coil module 740A, fig. 87 (b) is a perspective view showing only a part of the winding 741A in the coil module 740A, fig. 87 (c) is a perspective view showing only the winding holder 742A in the coil module 740A, and fig. 87 (d) is a side view of the coil module 740A. Fig. 88 (a) and (B) are cross-sectional views showing a cross-section of the coil module 740A, fig. 88 (a) is a cross-sectional view taken along line 88A-88A of fig. 87 (d), and fig. 88 (B) is a cross-sectional view taken along line 88B-88B of fig. 87 (d). In fig. 87 (d), the left side of the coil module 740A is the stator core 732 side, and in fig. 88 (a) and (b), the lower side of the coil module 740A is the stator core 732 side.

The coil module 740A includes a partial winding 741A formed by winding a conductive wire 743 in multiple layers, and an insulating winding holder 742A integrally provided on the partial winding 741A. The winding holder 742A is provided so that the partial winding 741A is insulated from the surroundings, and particularly so that the partial winding 741A is insulated from the stator core 732. The coil block 740A is formed in an elongated annular shape with the axial direction as a long side. The coil module 740A has a pair of linear portions 744 extending parallel to each other in the axial direction, and has a bent portion 745 extending in a direction orthogonal to the axial direction at one of both axial sides. Thus, the coil module 740A is formed in a substantially L shape as a whole.

The partial winding 741A includes a pair of intermediate conductor portions 746 provided in parallel and linearly; a first bridging portion 747 connecting the pair of intermediate wire portions 746 at one axial end side; and a second strap 748 connecting the pair of intermediate lead portions 746 at the other end side in the axial direction, and is formed in a ring shape by the pair of intermediate lead portions 746, the first strap 747, and the second strap 748. The pair of intermediate conductor portions 746 are provided at a predetermined coil pitch, and the intermediate conductor portions 746 of the partial windings 741 of the other phase can be arranged between the pair of intermediate conductor portions 746 in the circumferential direction. In this example, the pair of intermediate conductor portions 746 are provided at two coil pitches, and one intermediate conductor portion 746 in the other two-phase partial winding 741 is disposed between each of the pair of intermediate conductor portions 746.

The first strap 747 and the second strap 748 are provided as portions corresponding to the coil side ends CE1 and CE2 (see fig. 85), respectively. That is, the bridging portions 747 and 748 are coil side end lead portions which connect two circumferentially different intermediate lead portions 746 of the same phase to each other at the coil side end portions CE1 and CE 2. In the partial winding 741A, the first bridging portion 747 is a portion corresponding to the bent portion 745 in the coil module 740A, and is provided so as to be bent in a direction orthogonal to the intermediate wire portion 746, that is, in a direction orthogonal to the axial direction. In contrast, the second lap 748 is provided to linearly extend in the same direction as the axially inner intermediate lead 746, i.e., in the axial direction. Thus, the partial winding 741A is formed in a substantially L shape as a whole. In fig. 87 (d), a boundary BD between the coil side CS and the coil side ends CE1 and CE2 is indicated by a broken line.

In the partial winding 741A, an outer bent portion Y1 bent radially outward is provided at the first strap portion 747 (the strap portion 747 on the coil side end CE1 side in the partial winding 741A). The partial winding 741A is configured to be provided with an outer bend Y1 at the coil side end CE1 side and not to be bent in the radial direction at the coil side end CE2 side.

As shown in fig. 88 (a), the partial winding 741A is formed by winding the conductive wire 743 in multiple layers so that the cross section becomes a quadrangle. Fig. 88 (a) shows a cross section of the coil module 740A at the intermediate wire portion 746, in which the wire 743 is wound in multiple layers in a circumferentially and radially aligned manner. The circumferential length of the outer diameter side in the cross section of the partial winding 741A is the same as the circumferential length of the inner diameter side. In the lap portions 747 and 748, the partial winding 741A is formed by winding the conductive wire 743 in a plurality of layers so as to be arranged in the axial direction and the radial direction in a portion which is to be in the circumferential direction. In this example, the partial winding 741A is formed by winding the wire 743 in a concentric winding manner. However, the winding method of the wire 743 is arbitrary, and the wire 743 may be wound in a plurality of layers by α winding (japanese patent: アルファ roll) in addition to concentric winding.

In the cross section of the partial winding 741A, the circumferential length on the outer diameter side may be substantially trapezoidal, which is larger than the circumferential length on the inner diameter side. Thus, the intermediate lead portions 746 arranged in the circumferential direction can be equally spaced apart from each other in consideration of the difference in circumferential length between the outer diameter side and the inner diameter side.

As shown in fig. 87 (a), in the partial winding 741A, the end of the wire 743 is drawn from the first bridging portion 747 side, more specifically, from the tip of the bent portion 745, and the end is the winding end portions 743a, 743 b. The winding end portions 743a, 743b are a winding start end and a winding end of the wire 743, respectively. The winding end 743a is connected to the current input/output terminal, and the winding end 743b is connected to the neutral point.

In the partial winding 741A, it is preferable that a high potential is applied to the radially outer side. That is, in the partial winding 741A, when comparing the radially outer side and the radially inner side, the distance between the pair of intermediate conductor portions 746 becomes longer toward the radially outer side, and therefore, in consideration of this point, it is preferable to adopt a configuration in which a high potential is applied toward the radially outer side. Fig. 99 shows the winding sequence of wire 743 in partial winding 741A. In fig. 99, the intermediate conductor portions 746 in the same partial winding 741A are indicated by solid lines, and the intermediate conductor portions 746 in different partial windings 741B (i.e., partial windings 741B of different phases) are indicated by broken lines.

In the partial winding 741A, the wire 743 is wound so as to move from the radially outer side to the radially inner side, and the winding start end on the radially outer side is a winding end portion 743 a. The radially inner winding end is a winding overhang 743 b. In this case, the winding end portion 743a is connected to the current input/output terminal, and the winding end portion 743b is connected to the neutral point, so that a high potential is applied to the radially outer side. In addition, the winding order itself of the wire 743 may also be such that the winding start end and the winding end are opposite at the radially outer side and the radially inner side.

In fig. 99, the distance separating the intermediate lead portions 746 of different phases adjacent to each other in the circumferential direction differs between the radially outer side and the radially inner side. In this case, if the separation distance at the radially outer side is set to K1 and the separation distance at the radially inner side is set to K2, K1 > K2. That is, the more radially outward the distance between the intermediate lead portions 746 adjacent to each other in different phases in the circumferential direction is increased. Thus, the intermediate lead portions 746 adjacent in the circumferential direction are separated by appropriate separation distances corresponding to the potential differences.

The winding holder 742A has a bobbin shape and is made of an insulating material such as synthetic resin. Similarly to the partial winding 741A, the winding holder 742A is formed in a substantially L shape as a whole, and includes a portion provided along the intermediate lead portion 746 of the partial winding 741A and portions provided along the respective bridging portions 747 and 748.

As shown in fig. 88 (a), a winding holder 742A is provided so as to surround a partial winding 741A from three directions in a cross section of the partial winding 741A, and has a first wall portion 751 on the stator core 732 side, a second wall portion 752 on the opposite side of the stator core, and a third wall portion 753 connecting the first wall portion 751 and the second wall portion 752. The first wall 751 corresponds to a back-yoke-side insulating wall, the second wall 752 corresponds to a back-yoke-opposite-side insulating wall, and the third wall 753 corresponds to a circumferential insulating wall. The third wall portion 753 is provided circumferentially inward of a pair of linear portions 744 arranged circumferentially. The third wall portion 753 is provided in a direction extending toward the circular center of the stator core 732.

The winding holder 742A has a housing portion 754 formed by the first wall portion 751 to the third wall portion 753, and the partial windings 741A are disposed in the housing portion 754. In this case, the partial winding 741A is insulated by wall portions 751 to 753 on three sides, namely, a stator core 732 side, a stator core opposite side, and a circumferential single side. That is, the first wall portion 751 insulates the intermediate conductor portion 746 from the stator core 732. The intermediate conductor portion 746 is covered by the second wall portion 752 so as not to be exposed to the rotor 710 side (air gap side). The third wall portions 753 insulate the intermediate conductor portions 746 from each other in the circumferential direction.

In the winding holder 742A, when the thickness dimension in the thickness direction (radial direction) of the first wall portion 751 is T1, the thickness dimension in the thickness direction (radial direction) of the second wall portion 752 is T12, and the thickness dimension in the thickness direction (circumferential direction) of the third wall portion 753 is T13, the thickness dimension T12 of the second wall portion 752 is preferably smaller than the thickness dimension T11 of the first wall portion 751 (T11 > T12). That is, the second wall portion 752 is an insulating wall on the magnet 722 side (air gap side), and since the insulating wall is thin, the distance between the magnet 722 and the partial winding 741 can be shortened, specifically, the distance on the magnetic path can be shortened, and performance improvement can be expected. In addition, since the thickness dimension T12 of the second wall portion 752 is reduced as compared with the case where the distance between the magnet 722 and the partial winding 741 is the same, the air gap (gap interval) between the coil module 740 (holder surface) and the magnet 722 can be increased accordingly, and contact when the rotor 710 rotates can be suppressed. In addition, fig. 100 shows a structure in which T11 > T12 is set by making the thickness dimension T11 of the first wall portion 751 thicker and the thickness dimension T12 of the second wall portion 752 thinner than the structure in fig. 88 (a).

Further, since thickness dimension T11 of first wall portion 751 is larger than thickness dimension T12 of second wall portion 752, it is possible to secure an insulation distance from stator core 732 and improve the insulation performance thereof. However, T11 ═ T12 is also possible.

For example, the thickness dimension T13 of the third wall portion 753 is preferably the same as the thickness dimension T11 of the first wall portion 751. However, T13 > T11, or T13 < T11 are also possible.

As shown in fig. 100, the third wall portion 753 may be configured such that the thickness dimension T13 at each position radially inward and outward is different, and the thickness dimension T13 at the radially outward side is larger. That is, the third wall portion 753 has a tapered cross section that widens radially outward. In this case, by making the thickness dimension T13 of the third wall portion 753 larger radially outward than radially inward, it is possible to appropriately arrange the intermediate lead portions 746 arranged in the circumferential direction in consideration of the difference in circumferential length between the radially inward side and the radially outward side. That is, if the thickness dimension T13 of the third wall portion 753 is uniform in the radial direction, in the case where the cross section of the partial winding 741A is quadrangular, two intermediate lead portions 746 adjacent in the circumferential direction are too close on the third wall portion 753 side and too far apart on the opposite side thereof. Therefore, the rotating magnetic flux in the circumferential direction may be uneven. In contrast, in the configuration of this example, the rotational magnetic flux in the circumferential direction can be made uniform. In addition, the insulation performance in the circumferential direction can be made uniform. Further, since the formation of an excessive gap between the intermediate wire portion 746 and the third wall portion 753 at the radially outer side (outer peripheral side) is suppressed, it is also desirable in terms of positioning and fixing the intermediate wire portion 746 (the partial winding 741A).

In relation to the bent portion 745 of the coil module 740A, the first wall portion 751 of the pair of linear portions 744 is a wall portion on the opposite side of the bent portion 745 (an axially inner wall portion), and the second wall portion 752 is a wall portion on the bent portion 745 side (an axially outer wall portion).

The partial winding 741A is provided in the housing portion 754 in a state of abutting against or being close to the three wall portions 751 to 753, and is disposed in a region on the opposite side of the third wall portion 753 in the circumferential direction and inside the end portions of the first wall portion 751 and the second wall portion 752. That is, in the winding holder 742A, the third wall portion 753 is provided on one of the circumferential both sides of the intermediate lead portion 746 in the first and second wall portions 751, 752, and the protruding portions 751a, 752A that protrude further in the circumferential direction than the intermediate lead portion 746 are provided on the other side. The protruding portions 751A and 752a are remaining portions remaining in the circumferential direction with respect to the partial winding 741A. Thus, a vacant region SZ in which the partial winding 741A is not accommodated is provided on one side in the circumferential direction in the accommodating portion 754. In this case, the vacant region SZ prevents the partial winding 741A in the housing portion 754 from protruding outside the winding holder 742.

In short, the first wall portion 751 and the second wall portion 752 have extensions extending in the circumferential direction of the intermediate conductor portion 746 of the partial winding 741A on both sides in the circumferential direction of the intermediate conductor portion 746, and the third wall portion 753 extending in the radial direction from the first wall portion 751 and the second wall portion 752 is provided on one of the extensions on both sides in the circumferential direction. Further, protruding portions 751a, 752a are provided on one of the extensions on both sides in the circumferential direction.

The housing portion 754 is filled with a resin material as an insulating material, and a partial winding 741A is housed in a state molded with the resin material. Thus, the resin layer 755 is formed on the side of the receiving portion 754 opposite to the third wall portion 753 with the intermediate lead portion 746 interposed therebetween. In this case, since the resin material also enters the gaps between the wires 743 of the partial winding 741A, in the partial winding 741A, the adjacent portions of the wires 743 wound in multiple layers are bonded to each other using a mold resin as a bonding material. In this structure, the approaching portions of the conductive wires 743 wound in multiple layers in the partial winding 741A are joined to each other by a joining material, and the conductive wires 743 in the partial winding 741A can be maintained in a desired approaching state. That is, the state of multilayer winding in the partial winding 741A can be maintained in a desired state. As with the third wall part 753, the resin layer 755 is preferably configured such that the thickness dimension (circumferential dimension) at each position radially inside and radially outside is different, and the circumferential dimension at the radially outside is larger (refer to fig. 100). That is, it is preferable that the distance between the intermediate lead portions 746 of different phases adjacent to each other in the circumferential direction be different between the radially outer side and the radially inner side. Accordingly, the intermediate lead portions 746 arranged in the circumferential direction can be appropriately arranged in consideration of the difference in circumferential length between the radially inner side and the radially outer side. In fig. 100, the third wall portion 753 and the resin layer 755 correspond to a circumferential insulating portion.

In addition to resin molding, part of the winding 741A may be fixed in the housing portion 754 by an adhesive impregnated with varnish. In addition, both resin molding and impregnation of varnish may be performed. In addition, when the conductive wire 743 is a covered conductive wire in which a conductor is covered with an insulating film, the conductive wires 743 may be fixed (joined) to each other by self-melting of the insulating film. However, the housing portion 754 may be configured so as not to be filled with a resin material or the like, that is, the vacant region SZ may be configured as a space region.

The coil module 740A is assembled to the cylindrical stator core 732 from the radially outer side, and the first wall portion 751 on the stator core 732 side is formed as an arc surface with the same curvature as the outer peripheral surface of the stator core 732. This improves the adhesion of the coil module 740A to the stator core 732. The second wall portion 752 on the opposite side of the stator core may be formed in any of a straight line shape and an arc shape, but in this example, is formed in an arc shape concentric with the first wall portion 751.

The coil module 740A is assembled to the stator core 732 such that the bent portion 745 is positioned radially outward, and has the bent portion 745 on the second wall portion 752 side (i.e., on the opposite side of the first wall portion 751). In this case, the pair of linear portions 744 is provided with a bent portion 745 having a longer circumferential distance from the two second wall portions 752 than the circumferential distance from the two first wall portions 751, and the bent portion 745 has the same size as the longer circumferential distance and is radially outward.

As shown in fig. 87 (d), in the pair of linear portions 744 of the coil module 740A, in the vicinity of the boundary BD between the coil side portion CS and the coil side end portions CE1, CE2, protruding portions 756 protruding toward the opposite side of the bent portion 745, that is, the radially inner side (the stator core 732 side) are provided at two upper and lower positions. In the winding holder 742A, the protruding portion 756 is provided at the coil side end CE1 on the first strap 747 side and at a position axially outward of the boundary portion BD, and the protruding portion 756 is provided at the coil side end CE2 on the second strap 748 side and at a position axially outward of the boundary portion BD.

In other words, in the coil module 740A, the first wall portion 751 has a portion (yoke portion outer portion) extending axially outward from an axial end face of the stator core 732, and a protruding portion 756 protruding toward the stator core 732 side from a face circumferentially opposing the stator core 732 is integrally formed in this portion. The protrusion 756 is formed simultaneously with the first wall portion 751 by, for example, injection molding of a resin material.

When viewed in cross section of the coil module 740A, as shown in fig. 88 (b), a protrusion 756 is provided to protrude from the first wall portion 751 on the stator core 732 side. The protrusion 756 is configured to have an inclined surface 756a, and the inclined surface 756a is inclined to one side in a range from one end of the first wall portion 751 in the circumferential direction to the other end in the circumferential direction. In this example, the protruding portions 756 are formed such that the inner end portions (circumferentially inward) of the first wall portions 751 are higher in the pair of left and right linear portions 744. However, unlike the structure shown in fig. 88 b, the protruding portion 756 may be formed so that the outer end (outer side in the circumferential direction) of the first wall portion 751 is higher in the pair of left and right linear portions 744.

Next, the coil module 740B will be described.

The coil module 740B differs from the coil module 740A in the radial direction in which the bending portion 745 extends, and the basic structure is the same as that of the coil module 740A although the structure differs here, and therefore, the difference from the coil module 740A will be mainly described here.

Fig. 89 (a) is a perspective view of the coil block 740B, and fig. 89 (B) is a side view of the coil block 740B. Fig. 90 (a) and (B) are cross-sectional views showing a coil block 740B, fig. 90 (a) is a cross-sectional view taken along line 90A-90A of fig. 89 (B), and fig. 90 (B) is a cross-sectional view taken along line 90B-90B of fig. 89 (B). In fig. 89 (B), the left side of the coil block 740B is the stator core 732 side, and in fig. 90 (a) and (B), the lower side of the coil block 740B is the stator core 732 side.

The coil module 740B includes a partial winding 741B formed by winding a conductive wire 743 in multiple layers, and an insulating winding holder 742B integrally provided on the partial winding 741B. The coil module 740B is configured to have a pair of linear portions 744 extending parallel to each other in the axial direction, and a bent portion 745 extending in a direction orthogonal to the axial direction at one end side of both sides in the axial direction, and is formed in a substantially L shape as a whole.

The structure of the partial winding 741B is substantially the same as that of the partial winding 741A. That is, as with the partial winding 741A, the partial winding 741B has a pair of intermediate conductor portions 746 that are provided in parallel and linearly; a first bridging portion 747 connecting the pair of intermediate wire portions 746 at one axial end side; and a second strap 748 connecting the pair of intermediate lead portions 746 at the other end side in the axial direction, and is formed in a ring shape by the pair of intermediate lead portions 746, the first strap 747, and the second strap 748.

However, in the coil module 740A and the coil module 740B, the extending directions of the bent portions 745 in a state of being assembled to the stator core 732 are different, and the axial directions are opposite to each other. Thus, the coil modules 740A, 740B differ in structure.

In the partial winding 741B, an inner bent portion Y2 bent radially inward is provided at the first lap portion 747 (the first lap portion 747 on the coil side end CE2 side in the partial winding 741B). The partial winding 741B is configured to be provided with an inner bend Y2 at the coil side end CE2 side and not bent in the radial direction at the coil side end CE1 side.

In the partial winding 741B, the winding end portions 743a, 743B are drawn from the second overlapping portion 748 side, specifically, from the tip on the opposite side of the bent portion 745. Thus, in the state where the coil modules 740A and 740B are assembled to the stator core 732, the winding end portions 743a and 743B are drawn out to the same side in the axial direction (the side of the coil side end CE 1).

As shown in fig. 90 (a), the winding holder 742B has, similarly to the configuration of the winding holder 742A: first wall 751 on the stator core 732 side, second wall 752 on the opposite side of the stator core, and third wall 753 connecting first wall 751 and second wall 752 to each other. In the winding holder 742B, unlike the configuration of the winding holder 742A, in the pair of linear portions 744, the first wall portion 751 is a wall portion on the side of the bend 745 (an axially inner wall portion), and the second wall portion 752 is a wall portion on the opposite side of the bend 745 (an axially outer wall portion).

Coil module 740B is assembled to stator core 732 such that bent portion 745 is located radially inward, and has bent portion 745 on the first wall portion 751 side. In this case, the pair of linear portions 744 is provided with a bent portion 745 having the same size as the shorter circumferential distance and being radially inward, and the circumferential distance including the two first wall portions 751 is shorter than the circumferential distance including the two second wall portions 752.

As shown in fig. 89 (B), in the pair of linear portions 744 of the coil module 740B, in the vicinity of a boundary BD between the coil side portion CS and the coil side end portions CE1, CE2, protruding portions 756 protruding toward the bent portion 745 side, that is, radially inward (toward the stator core 732 side) are provided at two upper and lower positions. In the winding holder 742A, the protruding portion 756 is provided at the coil side end CE2 on the first strap 747 side and at a position axially outward of the boundary portion BD, and is provided at the coil side end CE1 on the second strap 748 side and at a position axially outward of the boundary portion BD. The protrusion 756 has the same structure as the winding holder 742A (see fig. 90 b).

A method of manufacturing the coil module 740 will be described. Here, although the method of manufacturing the coil module 740A is described, the same applies to the coil module 740B. First, the partial winding 741A is made into an air-core wound coil. Specifically, the wire 743 is wound in multiple layers using a jig, and a partial winding 741A having a shape shown in fig. 87 (b) is produced as an air-core winding coil. Then, after the partial winding 741A is manufactured, the winding holder 742A is assembled to the partial winding 741A. In this case, the winding holders 742A are preferably assembled to the respective partial windings 741A in a state of being divided into a plurality of pieces. The winding holders 742A can be preferably divided into two or three in the radial direction or the axial direction.

The coil module 740A can also be produced by winding the wire 743 around the winding holder 742A in multiple layers. In the winding holder 742A, a projection or a groove for guiding the lead 743 may be provided on an inner peripheral surface of the housing portion 754 for housing the partial winding 741A. It may be configured to be bound by the outer wire 743 to prevent the partial winding 741A from being released.

Then, in the winding holder 742A in which the partial winding 741A is integrated, resin is filled in the housing portion 754. Thereby, the resin layer 755 is formed in the receiving portion 754.

Next, the assembled state of the coil modules 740A and 740B to the stator core 732 will be described.

Fig. 91 is a sectional view showing a longitudinal section of the stator 730, fig. 92 is a sectional view showing a cross section of the stator 730, and fig. 93 is a sectional view showing the stator core 732, the end ring 733, and the coil module 740A separately from each other. Fig. 92 is a cross-sectional view taken along line 92-92 of fig. 91.

As shown in fig. 91, the coil modules 740A and 740B are assembled to the stator core 732 such that the bent portions 745 are axially opposite to each other and the bending directions are radially opposite to each other. In this case, interference of the circumferentially adjacent coil modules 740A, 740B with each other is avoided by the position and direction of the curved portion 745 in each coil module 740A, 740B. As for the partial windings 741A, 741B, an outer bent portion Y1 is provided in the partial winding 741A, and an inner bent portion Y2 is provided in the partial winding 741B, whereby interference of the circumferentially adjacent partial windings 741A, 741B with each other is avoided. The outer curved portion Y1 and the inner curved portion Y2 correspond to interference avoiding portions.

In addition to fig. 85, on the coil edge end CE1 side, the coil module 740B (the second lap 748 of the partial winding 741B) is located axially outside the coil module 740A (the first lap 747 of the partial winding 741A). Further, at the coil edge end CE2 side, the coil module 740A (the second lap 748 of the partial winding 741A) is located axially outside the coil module 740B (the first lap 747 of the partial winding 741B), and the partial windings 741A, 741B are arranged in a circumferential direction. Thus, the partial windings 741A and 741B are appropriately arranged in the circumferential direction while avoiding interference with each other, and the size can be reduced.

As shown in fig. 91, end rings 733 are provided at both ends of the stator core 732 in the axial direction, and the coil modules 740A and 740B are assembled to the stator core 732 in a state where the protruding portions 756 at two upper and lower positions are engaged with the end rings 733, respectively. Here, the protruding portions 756 of the coil modules 740A and 740B protrude so as to overlap with the axial end surfaces (upper end surface and lower end surface in the drawing) of the stator core 732 in the axial direction. Thereby, the stator core 732 is held in a state of being sandwiched in the axial direction by the pair of protrusions 756 in each coil module 740A, 740B (i.e., a state of being pressed in the axial direction). In this case, the stator core 732 is formed by laminating a plurality of core pieces 732a in the axial direction, and the stator core 732 is sandwiched between a pair of protrusions 756 in the laminating direction of the core pieces 732 a. This suppresses the following problems: the gap between the core pieces 732a is expanded, and the axial length of the stator core 732 is unexpectedly expanded. The pair of protrusions 756 function as pressing portions that press the axial end surfaces of the stator core 732 in the axial direction from the axially outer side.

In addition to the protruding portion 756, the stator core 732 preferably has a lamination holding structure on the radially inner side (i.e., the side opposite to the coil modules 740A and 740B in the radially inner and outer sides) for holding the lamination state of the plurality of core pieces 732 a. In fig. 91, a stack holding structure is provided at a position Q indicated by a thick broken line. As the lamination holding structure, a joint by welding of the core pieces 732a, a joint by caulking of the core pieces 732a, a joint by an adhesive (including varnish), a lamination holding by a frictional force of an outer tube member 772 (cylindrical member) assembled by being press-fitted into a radial inner side of the stator core 732, and the like are considered. By providing the lamination holding structure radially inside, the axial length dimension of stator core 732 can be further reduced appropriately.

A confinement ring 760 is attached to the outer periphery of the coil blocks 740A and 740B. Due to the restriction of the restricting ring 760, the coil modules 740A and 740B are pressed in a direction in which the protruding portion 756 engages with the end portion ring 733. In particular, since the stopper ring 760 is provided at a position axially overlapping with the engagement portion of the end ring 733 and the protruding portion 756, the engagement state of the end ring 733 and the protruding portion 756 can be more reliably maintained.

The confinement rings 760 are provided radially outward of the coil modules 740A, 740B, i.e., on the opposite surface side facing the magnets 722 of the rotor 710. Therefore, in order to avoid interference with the rotor 710 side, the radial thickness of the confinement ring 760 is preferably made as thin as possible. Further, the coil side end portions CE1 and CE2 may be provided in the region of the coil side end portions CS, not in the region of the coil side portion CS in the axial direction. In this case, the confinement rings 760 are preferably provided in the range of the coil side ends CE1 and CE2 and at positions radially outside the coil modules 740A and 740B. However, the position where the confinement rings 760 are provided and the number of the confinement rings 760 are arbitrary.

The confinement ring 760 is mounted to the outside of the second wall portion 752 of the winding holder 742. That is, the restricting ring 760 is configured to contact the winding holder 742 but not to contact the partial winding 741. Thus, for example, even in a configuration in which the metal restricting ring 760 is used to improve the fixing strength, the insulation of the partial winding 741 can be suppressed from being reduced.

As shown in fig. 92 and 93, the inclined surface 756a of the protrusion 756 comes into contact with the engagement surface 734 of the end ring 733. The engagement surface 734 of the end ring 733 corresponds to a first engagement portion, and the protrusion 756 of the coil modules 740A and 740B corresponds to a second engagement portion. The inclined surface 756a corresponds to an engaged surface. In this case, in the end portion ring 733, the plurality of engaging surfaces 734 are provided continuously in the circumferential direction so as to be inclined in different directions from each other, and a concave portion 735 is formed by two engaging surfaces 734 adjacent in the circumferential direction (see fig. 93). Then, one protrusion 756 of each of the two coil modules 740A, 740B enters the recess 735. Two protrusions 756 entering one recess 735 each bring the top of the protrusion 756 to the bottom of the recess 735. Thus, the third wall portions 753 of the coil modules 740A and 740B are in contact with each other in the circumferential direction. Further, at the top portion formed by the two engaging surfaces 734 adjacent in the circumferential direction, the first wall portions 751 and the second wall portions 752 of the coil modules 740A and 740B are respectively brought into a state of abutting or approaching each other in the circumferential direction.

In the above configuration, the respective protrusions 756 of the two coil modules 740A, 740B are guided in the direction of approaching each other in the circumferential direction by the two engaging surfaces 734 forming the recessed portion 735. This can suppress the backlash of the two partial windings 741 adjacent in the circumferential direction, and desirably suppress the positional displacement of the stator winding 731 due to vibration or electromagnetic force. Further, the gap between the intermediate conductor portions 746 can be reduced, and an improvement in the duty ratio can be expected.

The coil modules 740A and 740B each have a protrusion 756 on the first wall 751 at two locations spaced apart in the circumferential direction, and the protrusions 756 at the two locations are in contact with two engagement surfaces 734 of the end ring 733, the orientations of which are opposite to each other. In this case, in each of the coil modules 740A and 740B, the two protrusions 756 are engaged with the engagement surface 734 side of the end ring 733, and thus the positional deviation in the circumferential direction of each of the coil modules 740A and 740B can be further reduced.

In the structure in which the confinement rings 760 are attached to the radially outer sides of the coil modules 740A and 740B, the inclined surfaces 756a of the protrusions 756 abut against the engagement surfaces 734 of the end ring 733 in a pressed state. This enables the coil modules 740A and 740B to be fixed more firmly to the stator core 732.

In a state where the coil modules 740A and 740B are arranged in the circumferential direction, the partial windings 741 accommodated in the accommodating portion 755 are arranged at positions spaced apart from each other by predetermined intervals in the circumferential direction in the linear portion 744 of the coil modules 740A and 740B. More specifically, the windings 741 of the respective portions that are adjacent in the circumferential direction are separated from each other by the third wall portion 753 of the winding holder 742, or by the vacant region SZ in the housing portion 754 of the winding holder 742. This ensures insulation between the partial windings 741 of different phases adjacent in the circumferential direction.

Two third wall portions 753 are sandwiched between the partial windings 741 of different phases that are adjacent in the circumferential direction. In this case, the insulation of the stator winding 731 is further improved by overlapping two third wall parts 753. Alternatively, two vacant regions SZ are interposed between the partial windings 741 of different phases adjacent in the circumferential direction. In this case, the vacant regions SZ in the housing portion 754 are continuous in the circumferential direction, and the vacant regions SZ are molded with resin, so that the insulation of the stator winding 731 is further improved. That is, in the illustrated configuration, the third wall portions 753 of different winding holders 742 are provided continuously in the circumferential direction between the circumferentially adjacent intermediate conductor portions 746, or the protruding portions 751a, 752a of different winding holders 742 are provided continuously in the circumferential direction.

Regarding the thickness dimension T13 of the third wall portion 753 (refer to fig. 88 (a)), the thickness dimension T13 (i.e., 2 × T13) of the two third wall portions 753 is preferably larger than the thickness dimension T11 of the first wall portion 751. That is, 2 XT 13 > T11 is preferable. In this case, even if a larger potential difference occurs between the intermediate conductor portions 746 arranged in the circumferential direction than between the stator core 732 and the intermediate conductor portions 746, appropriate phase-to-phase insulation can be performed.

The radial and circumferential insulation structures of the coil modules 740A, 740B are supplemented. In the coil modules 740A, 740B, the first wall portion 751 and the second wall portion 752 have the third wall portion 753 on one of circumferential both sides of the middle wire portion 746 of the partial windings 741A, 741B, and have the protruding portions 751A, 752a on the other side. In the first wall portion 751 and the second wall portion 752, the portion to which the third wall portion 753 is connected and the protruding portions 751a and 752a correspond to extension portions extending in the circumferential direction of the intermediate lead portions 746, and the extension portions of the different coil modules 740A and 740B are provided so as to be circumferentially opposed to each other between the circumferentially adjacent intermediate lead portions 746. In this case, the intermediate lead portions 746 adjacent in the circumferential direction are spaced apart from each other by the extension portions of the first wall portions 751 of the coil modules 740A and 740B, thereby ensuring insulation between them. This makes it possible to achieve desirable interphase insulation in the circumferential direction in the intermediate conductor portion 746, in addition to radial insulation from the stator core 732.

In this example, particularly at one circumferential side of the circumferentially arrayed intermediate lead portions 746, the third wall portions 753 of the different coil modules 740A, 740B are disposed in a circumferentially opposed state to each other, and at the other circumferential side of the circumferentially arrayed intermediate lead portions 746, the third wall portions 753 are not present but are separated by the protruding portions 751a, 752 a. In this case, since one first wall portion 751 is provided between the stator core 732 and the intermediate conductor portions 746 arranged in the radial direction, and two third wall portions 753 are provided between the intermediate conductor portions 746 arranged in the circumferential direction, it is possible to perform appropriate phase insulation in consideration of the fact that a larger potential difference is generated between the intermediate conductor portions 746 arranged in the circumferential direction than between the stator core 732 and the intermediate conductor portions 746.

In a state where the coil modules 740A and 740B are assembled to the stator core 732, the protruding portions 756 and the end rings 733 of the coil modules 740A and 740B are preferably fixed to each other by an adhesive such as varnish. Further, the play may be suppressed by filling synthetic resin or varnish between the protruding portion 756 and the end ring 733 of the coil modules 740A and 740B.

The plurality of partial windings 741A and 741B are preferably formed such that the conductor cross-sectional area in the multilayer winding state and the winding number of the multilayer winding are the same. In this case, the interlinkage magnetic fluxes of the respective partial windings 741A and 741B constituting the parallel circuit can be made uniform in the phase winding of each phase. This eliminates the mutual potential difference between the windings 741A and 741B, and suppresses the generation of a circulating current in the parallel circuit. In addition, a decrease in motor efficiency and a decrease in rated heat performance associated with the generation of the circulating current can be suppressed.

Since the plurality of partial windings 741A and 741B have the same shape including the lap portions 747 and 748, the interlinkage magnetic flux can be made uniform including the leakage magnetic flux at the coil side end portions CE1 and CE 2. This can eliminate the potential difference in the respective windings 741A and 741B, and suppress the circulating current in the parallel circuit.

The stator 730 preferably has any one of the following configurations (a) to (C).

(A) In the stator 730, the inter-lead members are provided between the respective lead portions (intermediate lead portions 746) in the circumferential direction, and as the inter-lead members, a magnetic material is used that satisfies the relationship Wt × Bs ≦ Wm × Br when the circumferential width of the inter-lead member of one magnetic pole is Wt, the saturation magnetic flux density of the inter-lead member is Bs, the circumferential width of the magnet 722 of one magnetic pole is Wm, and the residual magnetic flux density of the magnet 722 is Br.

(B) In the stator 730, an inter-lead member is provided between the lead portions (intermediate lead portions 746) in the circumferential direction, and a nonmagnetic material is used as the inter-lead member.

(C) The stator 730 is configured such that no inter-wire member is provided between the respective lead portions (intermediate lead portions 746) in the circumferential direction.

Next, the internal unit 770 will be explained.

Fig. 94 and 95 are longitudinal sectional views of the inner unit 770. Fig. 95 shows a state in which bearings 791, 792 supporting the rotary shaft 701 are incorporated in the inner unit 770. For convenience of explanation, in the following description, the bearing 791 is also referred to as a first bearing 791, and the bearing 792 is also referred to as a second bearing 792. The first bearing 791 is a bearing provided on the proximal end side in the axial direction of the rotary shaft 701, that is, on the side of the coupling shaft 705, and the second bearing 792 is a bearing provided on the distal end side of the rotary shaft 701.

The inner unit 770 has an inner housing 771. The inner case 771 includes: an outer cylindrical member 772 having a cylindrical shape; an inner cylinder 773, the inner cylinder 773 having a cylindrical shape with an outer diameter smaller than that of the outer cylinder 772 and being disposed radially inside the outer cylinder 772; and a substantially disk-shaped end plate 774, the end plate 774 being fixed to one axial end side of the outer cylinder member 772 and the inner cylinder member 773. Each of the members 772-774 is preferably made of a conductive material, such as Carbon Fiber Reinforced Plastic (CFRP). The outer cylinder member 772 and the end plate 774 have the same outer dimensions, and the inner cylinder member 773 is provided in the space formed by the outer cylinder member 772 and the end plate 774. The inner cylinder member 773 is fixed to the outer cylinder member 772 and the end plate 774 by fasteners 775 such as bolts.

The stator core 732 is fixed to a radially outer side of the outer tube member 772 of the inner housing 771. Thereby, the stator 730 and the inner unit 770 are integrally formed.

A refrigerant passage 777 through which a refrigerant such as cooling water flows is formed between the outer tube member 772 and the inner tube member 773. The refrigerant passage 777 is annularly provided in the circumferential direction of the inner shell 771. Although not shown, a refrigerant pipe is connected to the refrigerant passage 777, and the refrigerant flowing in from the refrigerant pipe exchanges heat in the refrigerant passage 777 and then flows out to the refrigerant pipe again.

An annular space is formed radially inside the inner tubular member 773, and in this annular space, for example, it is preferable to arrange electric components constituting an inverter as a power converter. The electrical component is, for example, an electrical module in which a semiconductor switching element or a capacitor is packaged. By disposing the electrical module in a state of being in contact with the inner cylindrical member 773, the electrical module can be cooled by the refrigerant flowing through the refrigerant passage 777.

The outer cylindrical member 772 has a cylindrical boss portion 780 radially inside the inner cylindrical member 773. The boss portion 780 is provided in a hollow cylindrical shape, and the rotation shaft 701 is inserted through the hollow portion. The boss 780 is a bearing holding portion that holds the bearings 791 and 792, and the bearings 791 and 792 are fixed to the hollow portion (see fig. 95). The bearings 791 and 792 are, for example, radial ball bearings having a cylindrical inner ring, a cylindrical outer ring disposed radially outward of the inner ring, and a plurality of balls disposed between the inner ring and the outer ring, and are assembled to the inner unit 770 by fixing the outer ring to the boss 780.

A first fixing portion 781 to which the first bearing 791 is fixed and a second fixing portion 782 to which the second bearing 792 is fixed are provided in a hollow portion of the boss portion 780. The first bearing 791 and the second bearing 792 are different in physical constitution depending on the support position of the rotary shaft 701 in consideration of vibration and centrifugal load of the rotor 710, and the first bearing 791 supporting the base end side of the rotary shaft 701 is a large-sized bearing, that is, a bearing with a large support load. Therefore, the first fixing portion 781 is formed to have a larger diameter than the second fixing portion 782.

When the first bearing 791 and the second bearing 792 are compared, the radial inner clearance of the first bearing 791, that is, the radial clearance, is larger than the second bearing 792. In addition, the radial clearance is an amount of play of the inner ring, the outer ring, and the balls of the bearing in the axial direction. Here, the first bearing 791 is a bearing that is more susceptible to vibration and centrifugal load of the rotor 710 than the second bearing 792, and the effect of absorbing load is improved by increasing the radial clearance of the first bearing 791. Thereby, at the base end portion side of the rotary shaft 701, the load acting on the boss portion 780 is reduced, and the shake of the front end side of the rotary shaft 701 is suppressed.

The first fixing portion 781 is formed of a parallel surface 781a parallel to the axial direction and an orthogonal surface 781b orthogonal to the axial direction in the boss portion 780, and the first bearing 791 is fixed in a state of abutting on each of the surfaces. The second fixing portion 782 is formed of a parallel surface 782a parallel to the axial direction and an orthogonal surface 782b orthogonal to the axial direction in the boss portion 780, and the second bearing 792 is fixed in a state of being in contact with the respective surfaces.

Further, a third fixing portion 783 is provided in the hollow portion of the boss portion 780 on the side of the second fixing portion 782 of the first fixing portion 781 and the second fixing portion 782, and the third fixing portion 783 fixes the resolver 800 as a rotation sensor. The third fixing portion 783 is formed by expanding the diameter of the second fixing portion 782 in a stepwise manner.

As shown in fig. 77, the resolver 800 includes a resolver rotor 801 fixed to a rotating shaft 701, and a resolver stator 802 disposed to face the resolver rotor 801 radially outward. The resolver rotor 801 is in the shape of a circular plate and is coaxially provided on the rotating shaft 701 in a state where the rotating shaft 701 is inserted. The resolver stator 802 includes a stator core and a stator coil, not shown, and is fixed to the third fixing portion 783 of the boss portion 780.

As shown in fig. 94, in the hollow portion of the boss portion 780, a reduced diameter portion 784, 785 having a smaller diameter than the fixing portions 781, 782 is provided at a position between the first fixing portion 781 and the second fixing portion 782 in the axial direction. The diameter-reduced portion 784 is a hole having a smaller diameter than the first fixing portion 781, and the diameter-reduced portion 785 is a hole having a smaller diameter than the second fixing portion 782. The third fixing portion 783 for fixing the resolver 800 is provided at a position axially outward of the second fixing portion 782 as a portion having a larger diameter than the second fixing portion 782, in other words, at a position on the distal end side of the rotary shaft 701. The second fixing portion 782 and the third fixing portion 783 are provided at axially adjacent positions.

In this case, when hole machining is performed by boring machining or the like in the outer tubular member 772, the second fixing portion 782 and the third fixing portion 783 can be coaxially and continuously machined from the same direction. Therefore, the coaxiality of the second bearing 792 fixed to the second fixing portion 782 and the resolver stator 802 fixed to the third fixing portion 783 is improved, and the coaxiality of the resolver rotor 801 and the resolver stator 802 is improved. In this case, the vibration of the resolver stator 802 with respect to the resolver rotor 801 is reduced, thereby reducing the angle detection error in the resolver 800.

Next, the bus bar module 810 will be described. The bus bar module 810 is a winding connection member that is electrically connected to the partial windings 741 of the respective coil modules 740 in the stator windings 731, and connects one ends of the partial windings 741 of the respective phases in parallel for each phase, and connects the other ends of the partial windings 741 at a neutral point. Fig. 96 is a perspective view of the bus bar module 810, and fig. 97 is a sectional view showing a part of a longitudinal section of the bus bar module 810.

The bus bar module 810 has: an annular ring portion 811; a plurality of connection terminals 812 extending from the annular portion 811; three input-output terminals 813 provided for each phase winding; and a current detection terminal 814 connected to the current sensor of each phase.

As shown in fig. 97, the annular portion 811 is formed in an annular shape from an insulating member such as resin, for example, and has a plurality of bus bars 821 to 824 embedded therein. Each of the bus bars 821 to 824 includes a bus bar 821 for a U-phase, a bus bar 822 for a V-phase, a bus bar 823 for a W-phase, and a bus bar 824 for a neutral point, and is arranged in an axial direction such that plate surfaces thereof face each other. Then, the connection terminals 812 are connected to the bus bars 821 to 824 so as to protrude radially outward from the annular portion 811. As shown in fig. 96, the connection terminals 812 are arranged so as to be aligned in the circumferential direction of the annular portion 811 and extend in the axial direction on the radially outer side.

Fig. 98 schematically shows the connection positions of the connection terminals 812 with respect to the bus bars 821 to 824. In fig. 98, the left-right direction corresponds to the circumferential direction of the annular portion 811. In addition, in fig. 98, U denotes a connection terminal 812 connected to the U-phase winding, V denotes a connection terminal 812 connected to the V-phase winding, W denotes a connection terminal 812 connected to the W-phase winding, and NE denotes a connection terminal 812 connected to the neutral point.

As shown in fig. 98, the connection terminals 812(NE) connected to the neutral point are arranged every other in the circumferential direction, and one connection terminal 812(U) connected to the U-phase winding, one connection terminal 812(V) connected to the V-phase winding, and one connection terminal 812(W) connected to the W-phase winding are arranged between them, respectively. The above-described connection terminals 812 are provided in the same number as the winding end portions 743a, 743b of the respective partial windings 741 in the coil block 740, and one connection terminal 812 and one winding end portion 743a, 743b are connected, respectively. Further, at least any one of the connection terminal 812 and the winding end portions 743a, 743b is bent or curved in the radial direction as necessary to be in contact with each other, and is joined by welding, adhesion, or the like in this contact state.

The annular portion 811 has a plurality of fixed portions 815 on the inner peripheral side, and the bus bar module 810 is fixed to the end plate 774 of the inner case 771 by fastening members such as bolts being attached to the fixed portions 815.

The input/output terminals 813 are U-phase input/output terminals 813U, V phase input/output terminals 813V and W-phase input/output terminals 813W, and the input/output terminals 813 are connected to the bus bars 821 to 823 for each phase in the annular portion 811. The input/output terminals 813 each input/output electric power to/from an inverter, not shown, to/from the phase winding of each phase of the stator winding 731.

The annular portion 811 is provided with a current sensor 816 for each phase, and the detection result of the current sensor 816 is output to a control device, not shown, via a current detection terminal 814.

In the rotating electric machine 700 configured as described above, in the stator 730, the inter-wire members (so-called pole teeth) are not provided between the lead portions (intermediate lead portions 746) arranged at predetermined intervals in the circumferential direction, or the inter-wire members are weak in magnetic force even if provided. Therefore, the magnetic flux generated in the rotor 710 is directly linked to the lead portion of the stator winding 731, and there is a possibility that a decrease in motor efficiency or a decrease in rated thermal performance occurs as the copper eddy current loss increases. In particular, in the structure in which the magnetic flux density is enhanced by the orientation as described above, the influence of the copper eddy current loss may occur more significantly.

In contrast, in the above configuration, in the stator winding 731, the partial winding 741 is configured such that the conductive wires 743 are wound in multiple layers between the conductive wire portions of the same phase provided separately in the circumferential direction. The phase winding of each phase is formed by connecting a plurality of partial windings 741 in parallel with each other. Thus, in the stator winding 731, the cross-sectional area of each wire can be subdivided, so that the occurrence of copper eddy current loss can be suppressed, and further, the motor efficiency and the rated heat performance can be improved.

When the number of poles of the magnetic pole is P and the number of the partial windings 741A and the number of the partial windings 741B for each phase are N, the number of poles P is 4 × N, and the N partial windings 741A and the N partial windings 741B are all connected in parallel for each phase in the phase winding. In this example, the number (N) of the partial windings 741A and 741B of each phase is 6, and the number of poles P is 24. For example, fig. 84 shows a coil module 740 of one of three phases, and six coil modules 740A are shown as the coil module 740A including the partial winding 741A, and six coil modules 740B are shown as the coil module 740B including the partial winding 741B. In each phase winding, six partial windings 741A and 741B are all connected in parallel for each phase.

As shown in fig. 86, in the phase windings of each phase U, V, W, the number of parallel partial windings 741 is 12. In this case, since the partial windings 741A, 741B are all connected in parallel for each phase, the sectional area of each wire in the stator winding 731 can be minimized, and reduction in copper eddy current loss can be further achieved.

(modification 16)

In the present modification, the structure of the stator winding 731 in the rotating electrical machine 700 is changed. That is, in this example, the stator winding 731 is configured to use the coil modules 850(850A and 850B) shown in fig. 101 (a) and (B) instead of the coil module 740. Hereinafter, the stator 730 will be described mainly in terms of differences from modification 15. Note that the same reference numerals are given to the same components as those of modification 15, and the description thereof is omitted.

The coil module 850 of this example has the partial winding 851, and as a main difference from the coil module 740, the shape of the partial winding 851 is different from that of the partial winding 741 described above, and the partial winding 851 is not integrated with the winding holder 742, but is covered with a synthetic resin as an insulating material. That is, in the coil module 850, both ends of the partial coil 851 in the axial direction are bent in opposite directions to each other, and have a substantially zigzag shape in side view. In addition, the entire partial winding 851, which is an air-core wound coil, is covered with an insulating material. Similarly to the coil module 740, the coil module 850 is assembled so as to be arranged in the circumferential direction on the radially outer side of the stator core 732. In this example, the stator winding 731 has a phase winding composed of a plurality of partial windings 851 for each phase.

However, as the coil module 850, the partial winding 851 may be integrated with the winding holder in the same manner as the coil module 740. Further, in the coil module 850, a structure in which only a part of the partial winding 851 is covered with an insulating material may also be used.

The coil module 850 of the present example also includes two types of coil modules 850A and 850B, as in the case of the coil module 740. However, the partial windings 851 have the same structure in both of the coil blocks 850A and 850B. Fig. 102 (a) is a perspective view showing the structure of a partial winding 851, and fig. 102 (b) is a side view of the partial winding 851.

As shown in fig. 102 (a) and (b), the partial winding 851 is formed by winding a plurality of conductive wire members 852 in a plurality of layers, and has: a pair of linear portions 853 extending in parallel with each other in the axial direction; and coupling portions 854 and 855 that are provided at both ends of the pair of linear portions 853 in the axial direction and couple the pair of linear portions 853 to each other in a state of being bent in a radial direction intersecting the axial direction. The connection portions 854 and 855 are bent to the opposite sides, and thus the partial winding 851 has a substantially zigzag shape in side view. In this example, the coupling portions 854 and 855 have a shape that is curved in the radial direction at right angles to the axial direction with a predetermined curvature. One of the coupling portions 854, 855 is an inward curved portion that curves radially inward, and the other coupling portion 855 is an outward curved portion that curves radially outward.

More specifically, the one coupling portion 854 includes: a pair of curved portions 854a extending from the pair of straight portions 853 and curved in a radial direction; and a connecting portion 854b extending in a circumferential direction between the pair of curved portions 854 a. The other coupling portion 855 includes: a pair of curved portions 855a extending from the pair of straight portions 853 and curved in a radial direction; and a connecting portion 855b extending circumferentially between the pair of curved portions 855 a. The curved portions 854a, 855a are curved with a predetermined curvature in a direction orthogonal to the axial direction. However, the bending angle of the bent portions 854a and 855a bent in the radial direction may not be perpendicular to the axial direction, and may be an obtuse angle (non-perpendicular angle) with respect to the axial direction, for example.

In the partial winding 851, the pair of straight portions 853 are portions constituting a pair of intermediate lead portions as coil side lead portions, and the connection portions 854 and 855 are portions constituting overlapping portions as coil side end lead portions. The ranges of the pair of straight portions 853 corresponding to the intermediate lead portions (coil side lead portions) are different from each other in the coil modules 850A and 850B, and the details thereof will be described later.

The pair of straight portions 853 (intermediate lead portions) are provided at a predetermined coil pitch, and the straight portions 853 (intermediate lead portions) of the partial windings 851 of the other phase can be arranged between the pair of straight portions 853 in the circumferential direction. In this example, a pair of straight portions 853 are provided at two coil pitches, and one straight portion 853 of the partial windings 851 for the other two phases is disposed between the pair of straight portions 853.

The structure in which the wire material 852 in the partial winding 851 is wound in multiple layers is the same as that of the partial winding 741. The partial winding 851 includes a wire assembly 856 composed of a plurality of layers of wire materials 852, and the wire materials 852 are arranged in the circumferential direction and the radial direction so that the cross section of the wire assembly 856 becomes a quadrangle, for example, at a position crossing the straight portion 853 (see fig. 103).

Next, the coil modules 850A and 850B will be described.

Fig. 101(a) is a vertical cross-sectional view showing the shape of a vertical cross-section at the position of the linear portion 853 of the vertical-cut portion winding 851 of the coil module 850A, and fig. 101 (B) is a vertical cross-sectional view showing the shape of a vertical cross-section at the position of the linear portion 853 of the vertical-cut portion winding 851 of the coil module 850B. Fig. 103 is a cross-sectional view of the coil modules 850A and 850B (cross-sectional view taken along line 103 of fig. 101 a). In fig. 101(a) and (B), the left side of the coil modules 850A and 850B is the stator core 732 side (i.e., the radially inner side), and the lower side is the stator core 732 side in fig. 103.

As shown in fig. 101(a) and (B), each of the coil modules 850A and 850B has a partial winding 851 and a covering portion 860 provided so as to cover the entire outer surface of the partial winding 851, and has a substantially Z-shape in side view. As with partial winding 851, coil modules 850A and 850B are each configured as an annular body having a long side in the axial direction.

As shown in fig. 103, the covering portion 860 is provided so as to surround the partial winding 851 from four directions of the cross section of the partial winding 851, and has a first wall portion 861 on the stator core 732 side, a second wall portion 862 on the opposite side of the stator core, and a third wall portion 863 connecting the first wall portion 861 and the second wall portion 862. The first wall portion 861 is a back-yoke-side insulating wall (core-side insulating wall), the second wall portion 862 is an opposite-back-yoke-side insulating wall (opposite-core-side insulating wall), and the third wall portion 863 is a circumferential insulating wall. The third wall portion 863 is provided in an orientation extending toward the circular center of the stator core 732. Further, the structure in which the cover 860 has the first wall portion 861, the second wall portion 862, and the third wall portion 863 is common in the coil modules 850A, 850B.

Here, the ranges of the coil modules 850A and 850B corresponding to the coil sides CS in the axial direction are different from each other, and in fig. 101 (a) and (B), the ranges of the coil sides CS corresponding to the coil sides CS are located between boundary lines BD1 and BD2 between the coil sides CS and the coil side ends CE1 and CE2, respectively.

As shown in fig. 101 (a), in the coil module 850A, the part between the boundary lines BD1, BD2 of the partial winding 851 is an intermediate lead portion 871A, and the axially outer sides of the intermediate lead portion 871A are bridge portions 872A, 873A. As shown in fig. 101 (B), in the coil module 850B, the portion between the boundary lines BD1, BD2 of the partial winding 851 is an intermediate lead portion 871B, and axially outward of the intermediate lead portion 871B are bridge portions 872B, 873B. For convenience of description, the intermediate lead portions 871A and 871B, the crossover portions 872A and 872B, and the crossover portions 873A and 873B are collectively referred to as "crossover portions 873", respectively, of the coil modules 850A and 850B, respectively, as "intermediate lead portions 871", and " crossover portions 872A and 872B", respectively.

In the coil module 850A, the axial length of the lap portion 872A corresponding to the coil side end portion CE1 is longer than the axial length of the lap portion 873A corresponding to the coil side end portion CE 2. In contrast, in the coil module 850B, the axial length of the lap portion 872B corresponding to the coil side end portion CE1 is shorter than the axial length of the lap portion 873B corresponding to the coil side end portion CE 2.

The intermediate lead portion 871 is configured as a part of the straight portion 853 of the partial winding 851 described in fig. 102. The bridging portions 872 and 873 are formed as portions including the connection portions 854 and 855 of the partial winding 851 described with reference to fig. 102.

As described above, the coil modules 850A and 850B have the curved shape (substantially zigzag shape) conforming to the curved shape of the partial winding 851, and the axial lengths of the crossover parts 872A and 873A on the coil side end CE1 side are different from each other, and the axial lengths of the crossover parts 872B and 873B on the coil side end CE2 side are different from each other. This can avoid interference between the coil modules 850A and 850B when the coil modules are assembled to the stator core 732.

As shown in fig. 101 a, in the coil module 850A, in the vicinity of the boundary between the coil side CS and the coil side ends CE1, CE2, protruding portions 866 protruding radially inward (toward the stator core 732 side) are provided at two upper and lower positions. As shown in fig. 101B, in the coil module 850B, in the vicinity of the boundary between the coil side CS and the coil side ends CE1, CE2, there are provided projecting portions 867 projecting radially inward (toward the stator core 732 side) at two upper and lower positions. The projecting portions 866 and 867 of the coil modules 850A and 850B project radially inward from the first wall portion 861 on the stator core 732 side.

The cross-sectional shapes of the projections 866 and 867 may be the same as those of the projections 756 of the coil modules 740A and 740B (see fig. 88B and 90B), and it is preferable that the projections have an inclined surface inclined to one side in a range from one circumferential end to the other circumferential end of the first wall portion 861, for example.

Next, the assembled state of the coil modules 850A and 850B to the stator core 732 will be described. Fig. 104 is a cross-sectional view showing a longitudinal section of the stator 730, and fig. 105 is a partial plan view of the stator 730 as viewed from the axial side.

As shown in fig. 104 and 105, the coil modules 850A and 850B are assembled to the stator core 732 in a state in which end portions on both sides in the axial direction are bent to opposite sides, and the bending directions in which the modules are bent in the radial direction are the same. This causes the following states: on one axial side, the bridging portions 872A, 872B of the partial winding 851 are bent toward the stator core 732 side, i.e., radially inward, and on the other axial side, the bridging portions 873A, 873B of the partial winding 851 are bent toward the stator core opposite side, i.e., radially outward.

The coil modules 850A and 850B are assembled to the stator core 732 in a state in which the crossover parts 872A and 872B of the partial windings 851 at the coil side end part CE1 on one axial side intersect in the axial direction and the crossover parts 873A and 873B of the partial windings 851 at the coil side end part CE2 on the other axial side intersect in the axial direction. In this case, in the coil side end CE1, the crossover 872A on the coil block 850A side is disposed on the axially outer side, the crossover 872B on the coil block 850B side is disposed on the axially inner side, and in the coil side end CE2, the crossover 873A on the coil block 850A side is disposed on the axially inner side and the crossover 873B on the coil block 850B side is disposed on the axially outer side, opposite to the coil side end CE 1. Thus, the coil modules 850A and 850B can be arranged appropriately in a state in which a part of the coil modules overlaps in the circumferential direction and interference between the coil modules is avoided.

In the above configuration, the partial windings 851 of the coil modules 850A and 850B correspond to the first partial winding and the second partial winding, respectively, and the partial windings 851 are assembled to the stator core 732 while being shifted by at least the thickness of the wire aggregate 856 in the axial direction. In this case, even if the partial windings 851 having a common structure are used, the partial windings 851 can be appropriately arranged.

As illustrated in fig. 83, for example, end rings 733 are provided at both ends of the stator core 732 in the axial direction, and the coil modules 850A and 850B are assembled to the stator core 732 in a state where the protruding portions 866 and 867 (second engaging portions) at the upper and lower two locations of the coil modules 850A and 850B are respectively engaged with the engaging surface 734 (first engaging portion) of the end rings 733. The stator core 732 is held in the axial direction by the projections 866 and 867 on both sides in the axial direction of the coil modules 850A and 850B. The configuration in which the protruding portions 866 and 867 of the coil modules 850A and 850B are engaged with the end ring 733 is the same as that described with reference to fig. 91 to 93, and detailed description thereof is omitted.

As described above, according to the structure in which the end ring 733 on the stator core 732 side and the coil modules 850A and 850B are engaged with each other, it is possible to suppress positional deviation of the coil modules 850A and 850B (the partial windings 851) with respect to the circumferential direction of the stator core 732 and improve positional accuracy in the circumferential direction. In this case, even in the stator 730 having the non-slotting structure, the assembly of the stator winding 731 can be desirably performed. Further, since the coil modules 850A and 850B are configured to engage with the end rings 733 fixed to both end surfaces in the axial direction of the stator core 732, the coil modules 850A and 850B can be fixed to the stator core 732 as appropriate without providing unevenness or the like to the stator core 732 and without changing the performance and characteristics of the stator core 732. For example, as compared with the case where the stator core 732 is provided with projections and recesses for engagement, it is possible to suppress the cogging torque from being deteriorated.

In the case of manufacturing the partial winding 851 having the above-described structure, it is conceivable to form the bridging portions 872, 873 by bending the axial end portions of the annular air-core coil after the annular air-core coil is manufactured, in view of manufacturing convenience. However, when the axial end portion of the air-core coil is bent in the radial direction, the bending radii (curvatures) of the bent inner diameter side and the bent outer diameter side at the bent portion are different, and thus, in the tip end portions of the overlapping portions 872 and 873 of the partial winding 851, there is a possibility that a displacement of the tip end positions, that is, deformation (distortion) of the wire assembly occurs on the bent inner diameter side and the bent outer diameter side. The positional deviation of the lap part will be described specifically with reference to (a) and (b) of fig. 106. Fig. 106 (a) is a side view of a partial winding 881 as a conventional technique as viewed from the side, and fig. 106 (b) is a cross-sectional view showing a state in which a plurality of partial windings 881 are assembled to a stator core 885.

As shown in fig. 106 (a), the partial winding 881 has a crossover 882 provided in a state of being bent in a radial direction (left direction in the drawing), the crossover 882 being formed by bending an axial end of an air-core coil 883 formed by annularly winding a wire material. In this case, in the overlapping portion 882, the bending radius at the bending outer diameter side becomes larger (the curvature becomes smaller) than at the bending inner diameter side, and the length necessary for bending at the bending outer diameter side is longer than at the bending inner diameter side, and therefore, the displacement of the front end positions P1, P2 occurs at the bending inner diameter side and the bending outer diameter side.

In addition, as shown in fig. 106 (b), the coil cross section in the front end portion of the lap portion 882 is not rectangular but skewed into a parallelogram, thereby making the protruding length (protruding length) of the lap portion 882 in the radial direction longer. That is, in a state where a plurality of partial windings 881 are assembled to stator core 885, it is necessary to radially extend lap joint 882 in order to avoid interference between the partial windings 881, but if the coil cross section of the leading end portion of lap joint 882 is distorted into a parallelogram, the length of extension of lap joint 882 in the radial direction becomes longer. Accordingly, there is a possibility that a trouble such as interference with another member arranged radially inward of the stator core 885 is likely to occur in the stator winding 731.

Therefore, in this example, in the partial winding 851, deformation (distortion) of the coil cross section at the crossover portions 872, 873 is suppressed, and an increase in size of the stator winding 731 is suppressed. Fig. 107 (a) is a side view of the partial winding 851, and fig. 107 (b) is a vertical cross-sectional view in which the center portions of the bridges 872, 873 in the partial winding 851 are cut off.

As shown in fig. 107 (a) and (b), in the partial winding 851, the bridging portions 872 and 873 on both sides in the axial direction are bent in mutually opposite directions in the radial direction, and the lead length L1 on the outer diameter side of the bend is longer than the lead length L2 on the inner diameter side of the bend in the range from the tip end positions of the bridging portions 872 and 873 to the predetermined position a in the axial direction of the intermediate lead portion 871 (L1 > L2). In the conventional configuration of fig. 106, L1 is L2. The predetermined position in the axial direction of the intermediate wire portion 871 is preferably, for example, a boundary position between the coil side CS and the coil side ends CE1 and CE 2. Alternatively, the predetermined position may be an intermediate position within a range of the coil side CS.

More specifically, as shown in fig. 107 (a), the wire material 852 in the leading end portions of the bridging portions 903, 904 is oriented to extend in the radial direction in the side view of the partial winding 851, and as shown in fig. 107 (b), in the central portions (i.e., the connecting portions 854b, 855b) of the bridging portions 872, 873, the wire material 852 is oriented to extend in the circumferential direction orthogonal to the paper surface. Further, by setting the lead length L1 on the curved outer diameter side and the lead length L2 on the curved inner diameter side to L1 > L2, the distal end surfaces of the bent distal ends of the jumper portions 872, 873, that is, the distal end surfaces of the lead aggregate 856 at the connection portions 854b, 855b, are oriented parallel to the axial direction. In this case, in the bridging portions 872, 873, the radial projecting lengths at the curved outer diameter side and the curved inner diameter side (i.e., the radial projecting amounts from the intermediate wire portion 871) are equal.

In the configuration in which the bridging portions 872, 873 are bent perpendicularly to the axial direction, the bent tip end surfaces of the bridging portions 872, 873 are parallel to the axial direction, and therefore the cross section of the lead wire aggregate 856 at the connecting portions 854b, 855b is rectangular (see fig. 107 (b)). When the cross section of the wire aggregate 856 at the connecting portions 854b and 855b is rectangular, the aspect ratio of the cross section depends on the winding method of the wire material 852, and may be any of a vertical dimension, a vertical dimension > a horizontal dimension, and a vertical dimension < a horizontal dimension.

In addition, in the partial winding 851, the bending radii of the respective overlapping portions 872, 873 on both sides in the axial direction in bending in the radial direction are the same as each other. That is, when the bridging portions 872, 873 on both sides in the axial direction are compared, the bending radii on the bending outer diameter side are the same as each other and the bending radii on the bending inner diameter side are the same as each other in the bridging portions 872, 873.

Next, a method of manufacturing the partial winding 851 configured as described above will be described. As this manufacturing method, for example, the following methods are considered.

As shown in fig. 108 (a), a wire material 852 is annularly wound to produce an air core coil 875 having an I-shape in side view. After that, as shown in fig. 108 (b), the axial end portions of the air-core coil 875 are simultaneously bent in mutually different directions in the radial direction. At this time, since the inner bending diameter side and the outer bending diameter side of the respective bridging portions 872, 873 on both axial sides are opposite to each other, the wire members 852 are displaced in opposite directions in the axial direction on the radially inner side and the radially outer side of the air-core coil 875, and the difference in the wire length between the inside and the outside of the bending is cancelled out by the displacement. Thus, the respective bridging portions 872, 873 are formed so that the lead length L1 on the bend outer diameter side and the lead length L2 on the bend inner diameter side are L1 > L2 and the radial protrusion lengths (i.e., the radial protrusion amounts from the intermediate lead portion 871) on the bend outer diameter side and the bend inner diameter side are equal to each other.

As shown in fig. 108 (b), after the partial winding 851 is formed, the wire materials wound in multiple layers are preferably bonded to each other by a bonding agent such as a synthetic resin or varnish.

(manufacturing method 2) an air-core coil 875 shown in fig. 109 (a) is manufactured, and then, as shown in fig. 109 (b), tip end surfaces on both sides in the axial direction of the air-core coil 875 are molded so as to be inclined with respect to the axial direction by pressing a tilt plate or the like. The inclination directions of the front end surfaces of the air-core coils 875 are the same on both sides in the axial direction. Preferably, a molding die is used for the press molding. Alternatively, the air-core coil 875 having the shape shown in fig. 109 (b) may be produced by winding a wire material 852 using a bobbin or the like.

Then, as shown in fig. 109 (c), the axial end portions of the air-core coil 875 are bent in different directions from each other in the radial direction to form the bridging portions 872, 873. The bending may be performed simultaneously or separately. Thus, the respective bridging portions 872, 873 are formed so that the lead length L1 on the bend outer diameter side and the lead length L2 on the bend inner diameter side are L1 > L2 and the radial protrusion lengths (i.e., the radial protrusion amounts from the intermediate lead portion 871) on the bend outer diameter side and the bend inner diameter side are equal to each other.

In the case of the manufacturing method 2, the multi-layer wound wire materials may be bonded to each other with an adhesive after the molding in fig. 109 (b), or the multi-layer wound wire materials may be bonded to each other with an adhesive after the bending in fig. 109 (c).

In the coil modules 850A and 850B of this example, the crossover parts 872 and 873 on both axial sides of the partial winding 851 are bent in mutually opposite directions in the radial direction, and L1 > L2 is set, whereby the crossover parts 872 and 873 can be bent ideally while the difference in the wire lengths inside and outside the bending is cancelled out. In this case, when the bridging portions 872, 873 are formed by bending, the coil cross section at the distal end portions (the connecting portions 854b, 855b extending in the circumferential direction) of the bridging portions 872, 873 can be suppressed from being inclined, and the protruding length (protruding length) of the bridging portions 872, 873 in the radial direction can be reduced. As a result, the stator winding 731 can be easily manufactured, and the increase in size due to radial bending can be suppressed.

As shown in fig. 110, a flat wire material with a flat cross section may be used as the wire material 852. In this case, in the intermediate lead portion 871 of the partial winding 851, a lead material 852 having a flat cross section is laminated in the radial direction. Although not shown, the wire members 852 having a flat cross section are laminated in the radial direction in the bridging portions 872, 873. In this structure, as described above, it is preferable that the bridging portions 872, 873 on both axial sides are bent in opposite directions to each other in the radial direction, and L1 > L2 is set.

(modification 17)

In this example, a modification of a partial winding used for the stator winding 731 will be described. Fig. 111 (a) is a side view of the partial winding 901 in this example, and fig. 111 (b) is a front view of the partial winding 901.

As shown in (a) and (b) of fig. 111, the partial winding 901 includes: a pair of intermediate lead portions 902 provided in parallel and linearly with each other; and bridging portions 903, 904 connecting the pair of intermediate lead portions 902 at the one axial end side and the other axial end side, respectively, and the partial winding 901 is formed in a ring shape as a whole by the pair of intermediate lead portions 902 and the bridging portions 903, 904. The partial winding 901 includes a wire assembly 906 including a plurality of layers of wire materials 905, and a pair of intermediate wire portions 902 and bonding portions 903 and 904 are formed by the wire assembly 906. Further, the lead wire material 905 is wound in a plurality of layers, whereby the cross section of the lead wire aggregate 906 is formed in a rectangular shape.

The pair of intermediate lead portions 902 are provided at a predetermined coil pitch, and the intermediate lead portions 902 of the partial windings 901 of the other phases can be arranged between the pair of intermediate lead portions 902 in the circumferential direction. In this example, the pair of intermediate lead portions 902 are provided at two coil pitches, and one intermediate lead portion 902 of the other two-phase partial winding 901 is disposed between each of the pair of intermediate lead portions 902.

The bridging portions 903 and 904 are provided as portions corresponding to the coil side end portions CE1 and CE2 (see fig. 85), respectively. That is, the bridging portions 903 and 904 are provided as coil side end portion lead portions that connect the two same-phase intermediate lead portions 902, which are different in the circumferential direction, to each other at the coil side end portions CE1 and CE 2. Each of the bridging portions 903 and 904 is formed by bending toward the same side in the radial direction.

Although illustration is omitted, the partial winding 901 may be entirely or partially covered with an insulating material, or may be integrated with the winding holder.

Next, a state in which the partial winding 901 is assembled to the stator core 732 will be described. Fig. 112 is a vertical cross-sectional view showing a state in which a plurality of partial windings 901 are assembled to a stator core 732. Note that, for convenience of explanation, in fig. 112, a structure for insulation from stator core 732 in partial winding 901 is not shown.

As shown in fig. 112, the partial winding 901 includes two types of partial windings 901A and 901B, and the lengths of straight portions including the intermediate wire portions 902 of the partial windings 901A and 901B are different. The length of the straight portion of one partial winding 901A is longer than that of the other partial winding 901B, and the axial lengths are different from each other in the partial windings 901A, 901B. The partial windings 901A and 901B are different from each other in axial length, and can be arranged in the circumferential direction while being partially overlapped in the circumferential direction. Each partial winding 901 is assembled so as to overlap an axial end face of stator core 732 in the axial direction.

In the assembled state of the partial winding 901 shown in fig. 112, for example, as in fig. 82, one intermediate conductor portion 902 of the pair of intermediate conductor portions 902 of the partial winding 901 of the other phase is arranged between the pair of intermediate conductor portions 902 of the partial winding 901 of the other phase, and the crossover portions 903 of the partial windings 901 of the different phases are arranged in a state of being overlapped in the axial direction, whereby the intermediate conductor portions 902 of the respective phases are arranged in a predetermined order in the circumferential direction.

In this example, as in modification 16, deformation (distortion) of the coil cross section at the junctions 903, 904 in the partial winding 901 is suppressed, and an increase in the size of the stator winding 731 is suppressed, and the detailed structure of the junctions 903, 904 will be described below. The joints 903 and 904 have the same structure, and the structure of the joint 903 will be described here.

Fig. 113 (a) is an enlarged side view showing the structure of the crossover 903 in the partial winding 901, fig. 113 (b) is an enlarged front view showing the structure of the crossover 903, and fig. 113 (c) is a plan view of the crossover 903 as viewed from the axial direction.

As shown in fig. 113 (a) to (c), the bridge 903 has: a pair of bent portions 911 extending from the pair of intermediate lead portions 902 and bent in the radial direction; and a connection portion 912 extending in the circumferential direction between the pair of bent portions 911. Each bent portion 911 is bent at a predetermined curvature in a direction orthogonal to the axial direction. However, the bent portion 911 may be bent in the radial direction at an angle other than a right angle with respect to the axial direction, for example, at an obtuse angle (non-right angle) with respect to the axial direction.

In the bridging portion 903, each bent portion 911 is a portion where the lead assembly 906 extends in the radial direction while being bent from the intermediate lead portion 902 side, and the connection portion 912 is a portion where the distal end portions of the bent portions 911 are connected to each other in the circumferential direction. A turn-back portion 913 for turning back the wire assembly 906 in the axial direction is provided at an intermediate position of the connection portion 912.

The turn-back portion 913 is a portion of the connection portion 912 where the lead wire aggregate 906 is turned back in an axially overlapping state on both sides with the turn-back top portion 913a therebetween. In the folded portion 913, the lead assembly 906 is twisted in a range including the folded top portion 913a in the connection portion 912, and the lead assembly 906 is folded back in the axial direction. As shown in fig. 113 b, in the folded-back portion 913, the extending direction of the wire material 905 is a direction parallel to the axial direction as viewed from the bent tip side (radially inside) of the bridge portion 903.

In the folded portion 913, the direction in which the wire material 905 extends at the folded top portion 913a does not have to be parallel to the axial direction, and at least the wire material 905 at the folded top portion 913a may extend in the axial direction and the wire assembly 906 may be folded back in the axial direction.

In the above configuration, in the bridging portion 903, the wire assembly 906 extends from the side of each intermediate wire portion 902 in the radial direction and the circumferential direction, and a turn-back portion 913 is provided at an intermediate position in the circumferential direction to turn back the wire assembly 906 in the axial direction. In this case, in the turn-back portion 913, the lead wire aggregate 906 is turned back in the axial direction, and the upper and lower sides of the lead wire aggregate 906 are turned in the axial direction.

The connection of the lead material 905 in the bonding portion 903 will be specifically described with reference to (a) and (b) of fig. 113. In fig. 113 (a) and (b), a lead material 905X located on the innermost side of the folded portion 913 in the bonding portion 903 is hatched. The lead material 905X is switched in position from the lower side (axially inner side) to the upper side (axially outer side) of the lead assembly 906 by passing through the folded portion 913 in the bridging portion 903, and connects the inner diameter side and the outer diameter side of the bent portion 911. In this case, when the overlapping portion 903 is formed by bending, deformation (distortion) in the bending direction is less likely to occur. That is, the cross section of the wire assembly 906 in the tip end portion (the connection portion extending in the circumferential direction) of the bridging portion 903 is suppressed from being obliquely skewed.

In the pair of intermediate lead portions 902, the lead member 905X is positioned radially inward in one intermediate lead portion 902 and radially outward in the other intermediate lead portion 902, and is switched from the radially inward position to the radially outward position by the bridging portion 903. In this case, the pair of intermediate lead portions 902 are configured to have a radially outer facing surface facing the rotor 710, and the facing surface is turned 180 degrees. The wire material 905 is wound in such a manner that the winding positions radially inward and outward are opposite to each other between one intermediate wire portion 902 and the other intermediate wire portion 902.

In the bridging portion 903, the bending radii of the bent portions 911 at both circumferential sides, i.e., at the one intermediate conductor portion 902 side and the other intermediate conductor portion 902 side, are the same. This can further appropriately eliminate the positional displacement of the conductive wire 905 due to the bending in each bent portion 911 of the bridging portion 903.

Next, a method for manufacturing the partial winding 901 having the above-described structure will be described with reference to fig. 114 and 115. In fig. 114 (a) to (d), fig. 114 (a) and (b) are the previous steps in the winding manufacturing method, and fig. 114 (c) and (d) are the subsequent steps. In fig. 114 (a) to (d), the left-right direction of (a) and (c) of fig. 114 is referred to as "circumferential direction" and the left-right direction of (b) and (d) of fig. 114 is referred to as "radial direction" with reference to the direction of the stator winding 731 in the partial winding 901.

First, as shown in fig. 114 (a) and (b), an air core coil 920 having an I-shape in a side view is manufactured by winding a conductive wire 905 in a ring shape. The air-core coil 920 includes a wire assembly 906 made up of a plurality of layers of wire materials 905, and has a pair of straight portions 921 parallel to each other and a turn-back portion 922 connecting the pair of straight portions 921.

Next, as shown in fig. 114 (c) and (d), the pair of straight portions 921 are spaced apart from each other in the circumferential direction in the air-core coil 920. In addition, the interval between the pair of straight portions 921 is narrowed in the radial direction. By the forming in fig. 114 (c) and (d), a pair of intermediate conductor portions 902 arranged at a predetermined interval in the circumferential direction are formed in the pair of straight portions 921, and connection portions 912 ( bridge portions 903, 904 before bending) of the partial winding 901 are formed in portions including the folded-back portions 922.

Then, as shown in fig. 115, the axial ends of the air-core coil 920 are bent in the radial direction, respectively. As a result, the bridging portions 903 and 904 bent in the radial direction are formed on both axial sides of the air core coil 920.

In the partial winding 901 of this example, in the crossover portions 903 and 904, the lead wire aggregate 906 extends in the radial direction and the circumferential direction from the side of each intermediate lead portion 902, and a turn-back portion 913 for turning back the lead wire aggregate 906 in the axial direction is provided at an intermediate position in the circumferential direction. In this case, in the turn-back portion 913, the lead wire aggregate 906 is turned back in the axial direction, and the upper and lower sides of the lead wire aggregate 906 are turned in the axial direction. Therefore, when the bridging portions 903, 904 are formed by bending, the cross section of the wire assembly 906 at the distal end portions (connecting portions extending in the circumferential direction) of the bridging portions 903, 904 can be suppressed from being inclined, and the projecting length (protruding length) in the radial direction of the bridging portions 903, 904 can be reduced. As a result, the stator winding 731 can be easily manufactured, and the increase in size due to radial bending can be suppressed.

In the folded-back portion 913, the extending direction of the wire material 905 is a direction parallel to the axial direction as viewed from the bent tip side of the bridging portions 903, 904. Thus, the cross-sectional deformation (distortion) of the wire assembly 906 is less likely to occur, as compared with the case where the extending direction of the wire material 905 is not parallel to the axial direction.

In the pair of intermediate conductor portions 902 of the partial winding 901, the opposing surface opposing the rotor 710 is 180-degree inverted. In this case, the deformation (skew) of the cross section of the wire assembly 906 accompanying the bending is still suppressed in the bridging portions 903, 904.

In the bridging portions 903 and 904, the bend radius of one bent portion 911 and the bend radius of the other bent portion 911 in the pair of intermediate conductor portions 902 are the same as each other. In this case, the positional displacement of the wire member 905 due to the bending of each of the two bent portions 911 in the bridging portions 903 and 904 can be further appropriately eliminated. This enables optimization of the cross-sectional shape of the bridging portions 903 and 904.

In the partial winding 901 shown in fig. 111 (a) and (b), the bridging portions 903 and 904 on both sides in the axial direction are bent toward the same side in the radial direction, but this may be modified. For example, the directions of bending of the respective overlapping portions 903 and 904 may be opposite to each other on both sides in the axial direction. That is, one of the bridging portions 903 may be formed by bending inward in the radial direction, and the other bridging portion 904 may be formed by bending outward in the radial direction. In addition, only one of the axially opposite bridging portions 903 and 904 may be bent in the radial direction. That is, one of the bridging portions 903 may be formed by bending inward in the radial direction, and the other bridging portion 904 may be formed by not bending inward in the radial direction.

(Another example of modification 17)

As the partial winding of the stator winding 731, the partial winding 931 shown in (a) and (b) of fig. 116 may be used. Fig. 116 (a) is a side view of a part of winding 931, and fig. 116 (b) is a front view of the part of winding 931.

As shown in fig. 116 (a) and (b), the partial winding 931 is formed into an annular shape as a whole by having a pair of intermediate conductor portions 902 and bridging portions 903 and 904 on both sides in the axial direction, as in the partial winding 901 described above. In the partial winding 931, the junctions 903, 904 each have: a pair of bent portions 911 extending from the pair of intermediate lead portions 902 and bent in the radial direction; and a connection portion 912 extending in the circumferential direction between the pair of bent portions 911. Each bent portion 911 is bent at a predetermined curvature in a direction orthogonal to the axial direction. However, the bent portion 911 may be bent in the radial direction at an angle other than a right angle with respect to the axial direction, for example, at an obtuse angle (non-right angle) with respect to the axial direction. Further, a folded portion 913 for folding back the wire assembly 906 in the axial direction is provided at an intermediate position of the connection portion 912.

In the partial winding 931, as in the partial winding 901 described above (see fig. 111 (a) and (b)), the lead aggregate 906 extends in the radial direction and the circumferential direction from the side of each intermediate lead portion 902 in the bridging portions 903 and 904, and a turn-back portion 913 for turning back the lead aggregate 906 in the axial direction is provided at the intermediate position thereof. In addition, in each of the bent portions 911 arranged in the circumferential direction, the bending radii of bending in the radial direction are the same as each other.

However, the partial winding 931 is different from the partial winding 901 in the axial direction in the bent portion 911. Specifically, in the connection portion 912 between the pair of bent portions 911, when a portion connected to an axially outer end portion of both ends of the folded portion 913 extending in the axial direction is a first portion 915 and a portion connected to an axially inner end portion is a second portion 916, the portions 915 and 916 are axially separated from each other, and in a state where the portions are axially separated from each other, the end portions on the intermediate wire portion 902 side are connected to the bent portions 911, respectively. Further, the axial positions of the respective bent portions 911 are different from each other.

In the partial winding 931, one of the intermediate lead portions 902 of the pair of intermediate lead portions 902 is provided with first portions 915 located axially outward at both axial ends thereof, and the other intermediate lead portion 902 is provided with second portions 916 located axially inward at both axial ends thereof.

Fig. 117 is a plan view showing a state in which a plurality of partial windings 931 are assembled to stator core 732. Fig. 117 is a plan view of stator 730 viewed in the axial direction from the bridge 903 side, and the circumferential surface of stator core 732 is substantially arc-shaped, but for convenience of explanation, the circumferential surface of stator core 732 is shown linearly. Therefore, in fig. 117, the vertical direction corresponds to the radial direction, and the horizontal direction corresponds to the circumferential direction.

In fig. 117, one intermediate lead portion 902 of the pair of intermediate lead portions 902 of the partial winding 931 of the other phase is disposed between the pair of intermediate lead portions 902 of the partial winding 931. The overlapping portions 903 of the partial windings 931 of different phases are arranged so as to overlap each other in the axial direction. Thereby, the intermediate conductor portions 902 of the respective phases are arranged in a predetermined order in the circumferential direction.

In more detail, in the overlapping portion 903 of each part winding 931, a first portion 915 on one side and a second portion 916 on the other side of the connecting portion 912 sandwiching the turn-back portion 913 are separated from each other in the axial direction. Then, the respective partial windings 931 (the different-phase partial windings 931) adjacent to each other in a state in which a part thereof overlaps in the circumferential direction are assembled to the stator core 732 in a state in which the first portion 915 of the overlapping portion 903 of one partial winding 931 is positioned axially outward, the first portion 915 of the overlapping portion 903 of the other partial winding 931 is positioned axially outward, and the respective portions 915 and 916 intersect each other in the axial direction. Although not shown, the same applies to the bridging portion 904 on the other axial side.

In this case, in the overlapping portions 903, 904, a step can be applied in the circumferential direction by the folded portion 913 extending in the axial direction. Further, the axial length of the stator winding 731 can be reduced by arranging the partial windings 931 in a row in the circumferential direction while partially overlapping them, using the step difference between the overlapping portions 903 and 904.

(further example of modifications 15 to 17)

The stator winding 731 in the rotating electric machine 700 may be configured to have two-phase windings (U-phase winding and V-phase winding). In this case, for example, the pair of intermediate conductor portions 746 may be provided at a pitch of one coil in the partial winding 741, and the intermediate conductor portions 746 in the partial winding 741 of the other phase may be disposed between the pair of intermediate conductor portions 746.

As the stator 730 using the stator winding 731 shown in modifications 16 and 17, the stator 730 not including the stator core 732 may be configured. That is, the plurality of partial windings 851 (coil block 850) or the plurality of partial windings 901 may be coupled to each other in the circumferential direction to form a cylindrical stator winding 731, and the stator 730 may be configured by the stator winding 731, or a cylindrical body made of a nonmagnetic material may be used instead of the stator core 732, and the plurality of partial windings 851 (coil block 850) or the plurality of partial windings 901 may be assembled to the cylindrical body.

Although the outer rotor type surface magnet type rotating electric machine has been described as the rotating electric machine 700 according to modification examples 15 to 17, the outer rotor type surface magnet type rotating electric machine may be embodied as an inner rotor type surface magnet type rotating electric machine. In the case of the inner rotor type, the plurality of coil modules 740 and 850 are preferably arranged in a row on the radially inner side of the stator core 732 in the stator 730.

The stator 730 may be configured such that a stator core having a plurality of pole teeth in the circumferential direction is used, and the stator winding 731 ( partial windings 851, 901, 931) is assembled to the stator core.

The rotating electric machine is not limited to a star-connected rotating electric machine, and may be a delta-connected rotating electric machine.

As the rotating electric machine 700, a rotating armature type rotating electric machine having an armature as a rotor can be used in addition to a rotating field type rotating electric machine having a field element as a rotor.

The disclosure of the present specification is not limited to the illustrated embodiments. The present disclosure includes the illustrated embodiments and variations thereon by those skilled in the art. For example, the present disclosure is not limited to the combinations of components and/or elements shown in the embodiments. The disclosure may be implemented in various combinations. The present disclosure may have an additional part that can be added to the embodiment. The present disclosure includes embodiments in which components and/or elements of the embodiments are omitted. The present disclosure includes substitutions or combinations of parts and/or elements between one embodiment and another. The technical scope of the disclosure is not limited to the description of the embodiments. The technical scope of the disclosure should be understood to be expressed by the description of the claims, and also includes all modifications equivalent in meaning and scope to the description of the claims.

Claims (8)

1. An armature (730) comprising a multi-phase armature winding (731) having a cylindrical shape and having, for each phase, a phase winding composed of a plurality of partial windings (851),

the partial winding has: a pair of intermediate lead portions (871) provided at a predetermined interval in the circumferential direction; and bridging portions 872, 873 provided on one end side and the other end side in the axial direction and connecting the pair of intermediate lead portions annularly, in the pair of intermediate lead portions and each of the bridging portions, a lead material 852 is wound in multiple layers and each of the bridging portions on both sides in the axial direction is bent in the radial direction,

the overlapping portions on both axial sides are bent in opposite directions to each other in a radial direction,

the lead length L1 on the outside diameter side of the bend and the lead length L2 on the inside diameter side of the bend are L1 > L2 in the range from the front end position of the bridging portion to a predetermined position in the axial direction of the intermediate lead portion.

2. The armature of claim 1,

a tip end surface of the lap joint portion which becomes a curved tip end is formed in a direction parallel to the axial direction.

3. The armature of claim 1 or 2,

The lap joint part has: a pair of bent portions (854a, 855a) extending from the pair of middle lead portions and bent in a radial direction; and a connecting portion (854b, 855b) extending in a circumferential direction between the pair of bent portions, the pair of bent portions being bent in a direction orthogonal to the axial direction,

in the connecting portion, a wire aggregate (856) made of a plurality of layers of the wire material has a rectangular cross section.

4. The armature of any of claims 1 to 3,

in the overlapping portion on one axial side and the overlapping portion on the other axial side, the bending radii of the radial bends are the same as each other.

5. The armature of any of claims 1 to 4,

one of the pair of intermediate lead portions of the partial winding of the other phase is disposed between the pair of intermediate lead portions of the partial winding, and the lap portions of the partial windings of different phases are disposed in a state of being overlapped in the axial direction, whereby the intermediate lead portions of each phase are arranged in a predetermined order in the circumferential direction.

6. The armature of claim 5,

includes a base member (736) having a cylindrical back yoke (732) and integrating the armature winding with the base member by assembling the partial winding on a radially outer side or a radially inner side of the back yoke,

The partial windings have a first partial winding and a second partial winding assembled to the base member while being shifted at least in the axial direction by the thickness of a wire aggregate (856) made of a plurality of layers of the wire material,

on one of both sides of the base member in the axial direction, the lap portions in the first partial winding and the second partial winding are respectively bent toward the radially inner side, and the lap portions of the first partial winding are arranged on the axially inner side, and the lap portions of the second partial winding are arranged on the axially outer side,

on the other of the two axial sides of the base member, the lap portions of the first and second partial windings are respectively bent toward the radially outer side, and the lap portion of the first partial winding is disposed on the axially outer side and the lap portion of the second partial winding is disposed on the axially inner side.

7. The armature of any of claims 1 to 6,

includes a base member (736) having a cylindrical back yoke (732) and integrating the armature winding with the base member by assembling the partial winding on a radially outer side or a radially inner side of the back yoke,

The armature winding has a plurality of coil modules (850) including the partial winding and a back yoke side insulating wall (861) provided on the back yoke side of the partial winding,

the plurality of coil modules are arranged in a circumferential direction on a radially inner side or a radially outer side of the base member,

the base member is provided with a first engaging portion (734), the back yoke side insulating wall of the coil module is provided with second engaging portions (866, 867), and the coil module is fixed to the base member in a state where the first engaging portion and the second engaging portion are engaged in the circumferential direction.

8. The armature of claim 7,

the base member has an end ring (733) fixed to at least one of end faces of both axial ends of the back yoke,

the end ring is provided with the first engagement portion.

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