JP2012016189A - Permanent-magnet rotating electrical machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent-magnet rotating electrical machine capable of decreasing a maximum value of a line voltage without decreasing a torque constant.SOLUTION: A protrusion part 31 protruding over a prescribed section in a circumferential direction is formed at magnetic poles 23A and 23B in an outer peripheral part of a rotor 20. Assuming that θ1 is a rotor magnetic pole open angle and θ2 is a protrusion part open angle centering around a magnetic pole center P, the protrusion part 31 is formed so as to satisfy (4/9)θ1<θ2<(2/3)θ1 in electrical degrees.

Description

  The present invention relates to an IPM (Internal Permanent Magnet) type permanent magnet rotating electric machine having a structure in which a permanent magnet is embedded in a rotor core.

  The IPM type permanent magnet type rotating electrical machine has an advantage that the reluctance torque resulting from the difference in the magnetic resistance at each part in the circumferential direction of the rotor can be used as the electric torque in addition to the magnet torque due to the magnet magnetic flux. In this rotating electrical machine, an induced voltage (counterelectromotive voltage) is generated in the stator winding as the rotor rotates, so that the line voltage caused by this induced voltage exceeds the withstand voltage of the control circuit in the high-speed rotation range. It is designed not to be.

  In conventional rotating electrical machines, the peak (maximum value) of the line voltage is lowered by reducing the magnet amount of the permanent magnet and the number of turns of the coil, or by reducing the lamination thickness of the laminated steel plates constituting the rotor core. The control circuit was protected.

  In the invention described in Patent Document 1, each opening angle is set so that the cogging torque generated by the effective magnetic pole opening angle is canceled by the cogging torque generated by the effective convex portion opening angle.

JP 200284693 A

  However, in the conventional method of reducing the peak of the line voltage, the torque constant (at the same time by reducing the magnet amount of the permanent magnet and the number of turns of the coil, or reducing the lamination thickness of the laminated steel plates constituting the rotor core) Kt = motor torque / phase current) was also to be reduced. In other words, conventionally, the torque constant and the induced voltage are balanced so that the line voltage does not exceed the withstand voltage of the control circuit.

  Further, in the rotating electrical machine described in Patent Document 1, although the cogging torque can be reduced, it is not considered to lower the induced voltage. Therefore, the line voltage exceeds the withstand voltage of the control circuit during high-speed rotation. There was a fear.

  The present invention has been made in view of the above-described situation, and an object of the present invention is to provide a permanent magnet type rotating electrical machine capable of lowering an induced voltage without reducing a torque constant.

In order to achieve the above object, the invention according to claim 1
A stator having a plurality of stator magnetic poles (for example, a stator 11 in an embodiment described later);
A rotor core (for example, a rotor core 21 in an embodiment described later) and magnetic poles (for example, a first magnetic pole portion 23A and a second magnetic pole portion 23B in an embodiment described later) disposed inside the rotor core. And a plurality of permanent magnet portions (for example, permanent magnets 22a, 22a, 22b, and 22b in the embodiments described later), and are rotatably disposed opposite to each other via a predetermined gap on the radially inner side of the stator. A permanent magnet type rotating electrical machine (for example, a rotating electrical machine 10 in an embodiment to be described later) including a rotor (for example, a rotor 20 in an embodiment to be described later),
On the outer peripheral portion of the rotor, a convex portion (for example, a convex portion 31 in an embodiment described later) protruding over a predetermined section in the circumferential direction is formed on each magnetic pole,
The protrusions satisfy the electrical angle of (4/9) θ1 <θ2 <(2/3) θ1, where the rotor magnetic pole opening angle is θ1 and the protrusion opening angle is θ2, respectively. It is formed.

In addition to the configuration of claim 1, the invention according to claim 2
A non-convex portion (for example, a non-convex portion 41 in the embodiment described later) sandwiching the convex portion from both sides in the circumferential direction is formed on each magnetic pole on the outer peripheral portion of the rotor,
A boundary portion between the convex portion and the non-convex portion has one bending point (for example, a bending point 50 in an embodiment described later) that protrudes from the outer diameter side of the rotor.

In addition to the structure of claim 1, the invention according to claim 3
A non-convex portion (for example, a non-convex portion 41 in the embodiment described later) sandwiching the convex portion from both sides in the circumferential direction is formed on each magnetic pole on the outer peripheral portion of the rotor,
The boundary between the convex portion and the non-convex portion has a bending point (for example, 51 in an embodiment described later) that is convex on the outer diameter side of the rotor, and a convex portion on the inner diameter side of the rotor. And a bending point (for example, 52 in an embodiment described later).

In addition to the structure of any one of Claims 1-3, the invention which concerns on Claim 4
The outer peripheral surface of the convex portion is formed in an arc shape centering on a rotation axis of the rotor (for example, a rotation axis O in an embodiment described later).

The invention according to claim 5 includes, in addition to the configuration of claim 4,
The inner peripheral surface of the stator has a similar shape to the outer peripheral surface of the convex portion.

In addition to the structure of any one of Claims 1-5, the invention which concerns on Claim 6 is
In the rotor, a magnetic flux short-circuit prevention portion (for example, a groove portion 26 in an embodiment described later) is formed between the magnetic poles adjacent in the circumferential direction.

The invention according to claim 7 includes, in addition to the configuration of claim 6,
The magnetic flux short-circuit prevention part is a groove part (for example, a groove part 26 in an embodiment described later) recessed from the outer peripheral surface of the rotor,
The innermost diameter part of the groove part is located radially inward from the outermost diameter part of the permanent magnet part.

In addition to the structure of any one of Claims 1-7, the invention which concerns on Claim 8 is
θ2 = (5/9) θ1.

In addition to the structure of any one of Claims 1-8, the invention which concerns on Claim 9 is
The ratio between the number of magnetic poles of the stator and the number of magnetic poles of the rotor is set to 3: 2.

In order to achieve the above object, the invention according to claim 10 provides:
A stator having a plurality of stator magnetic poles (for example, a stator 11 in an embodiment described later);
A rotor core (for example, a rotor core 21 in an embodiment described later) and magnetic poles (for example, a first magnetic pole portion 23A and a second magnetic pole portion 23B in an embodiment described later) disposed inside the rotor core. And a plurality of permanent magnet portions (for example, permanent magnets 22a, 22a, 22b, and 22b in the embodiments described later), and are rotatably disposed opposite to each other via a predetermined gap on the radially inner side of the stator. A permanent magnet type rotating electrical machine (for example, a rotating electrical machine 10 in an embodiment to be described later) including a rotor (for example, a rotor 20 in an embodiment to be described later),
On the outer peripheral portion of the rotor, concave portions (for example, non-convex portions 41 in the embodiments described later) that are recessed over a predetermined section in the circumferential direction are formed on both sides in the circumferential direction of each magnetic pole,
The recess has an electrical angle of (1/6) when the rotor magnetic pole opening angle is θ1 with respect to the magnetic pole center of the rotor and the recess opening angle from the rotor magnetic pole end side toward the magnetic pole center side is θ3. ) Θ1 <θ3 <(5/18) θ1 is formed.

In addition to the structure of Claim 10, the invention according to Claim 11
A non-concave portion (for example, a convex portion 31 in an embodiment described later) sandwiched between the concave portions is formed on each magnetic pole on the outer peripheral portion of the rotor,
A boundary portion between the non-recessed portion and the recessed portion has one bending point (for example, a bending point 50 in an embodiment described later) that protrudes from the outer diameter side of the rotor.

The invention according to claim 12 adds to the structure of claim 10,
A non-concave portion (for example, a convex portion 31 in an embodiment described later) sandwiched between the concave portions is formed on each magnetic pole on the outer peripheral portion of the rotor,
A bending point where the boundary between the non-recessed portion and the recessed portion is convex on the outer diameter side of the rotor (for example, 51 in an embodiment described later), and a bending point where the inner diameter side of the rotor is convex (For example, 52 in an embodiment described later).

In addition to the structure of Claim 11 or 12, the invention according to Claim 13
The outer peripheral surface of the non-recessed portion is formed in an arc shape centering on a rotation axis of the rotor (for example, a rotation axis O in an embodiment described later).

In addition to the structure of Claim 13, the invention according to Claim 14
The inner peripheral surface of the stator is formed in an arc shape having a larger diameter than the outer peripheral surface of the non-recessed portion.

In addition to the configuration of any one of claims 10 to 14, the invention according to claim 15 includes:
In the rotor, a magnetic flux short-circuit prevention portion (for example, a groove portion 26 in an embodiment described later) is formed between the magnetic poles adjacent in the circumferential direction.

The invention according to claim 16 includes, in addition to the configuration of claim 15,
The magnetic flux short-circuit prevention part is a groove part (for example, a groove part 26 in an embodiment described later) recessed from the outer peripheral surface of the rotor,
The innermost diameter part of the groove part is located radially inward from the outermost diameter part of the permanent magnet part.

In addition to the structure of any one of Claims 10-16, the invention which concerns on Claim 17
θ3 = (2/9) θ1.

In addition to the structure of any one of Claims 10-17, the invention which concerns on Claim 18 is
The ratio between the number of magnetic poles of the stator and the number of magnetic poles of the rotor is set to 3: 2.

  According to the first aspect of the present invention, the peak of the line voltage can be lowered without changing the torque constant by changing the shape of the outer peripheral portion of the rotor. As a result, a margin can be provided for the withstand voltage of the control circuit, so that the reliability can be improved.

  According to the second aspect of the present invention, since one bending point is used, the other of the convex portion and the non-convex portion is formed in an inclined shape (tapered shape). The peak is leveled (flattened).

  According to the invention of claim 3, by setting the two bending points, the other is formed in a stepped shape with respect to one of the convex portion and the non-convex portion. The change in the outer diameter can be made large in a narrow range, and the degree of freedom of the outer peripheral shape increases.

  According to the fourth aspect of the present invention, it is possible to arrange the rotor and the stator closer to each other by forming the convex portion in an arc shape, and it is possible to further suppress the decrease in the torque constant.

  According to the invention of claim 5, the rotor and the stator can be arranged closer to each other.

  According to the sixth aspect of the present invention, it is possible to prevent the magnetic flux from turning between adjacent magnetic poles and reducing the amount of magnetic flux to the stator.

  According to invention of Claim 7, the stress which acts on a rotor core by the centrifugal force which acts on a permanent magnet disperse | distributes, and the sustainability of rotor strength improves.

  According to the invention of claim 8, the peak of the line voltage is leveled most.

  According to the invention of claim 10, by changing the shape of the outer peripheral portion of the rotor, the peak of the line voltage can be lowered without reducing the torque constant. As a result, a margin can be provided for the withstand voltage of the control circuit, so that the reliability can be improved.

  According to the invention of claim 11, by setting one bending point, the other of the non-recessed portion and the recessed portion is formed in an inclined shape (tapered shape). More leveling (flattening) is performed.

  According to the twelfth aspect of the present invention, since the two bending points are used, the other of the non-recessed portion and the recessed portion is formed in a stepped shape. It can be made large in a narrow range, and the degree of freedom of the outer peripheral shape increases.

  According to the thirteenth aspect of the present invention, the rotor and the stator can be arranged closer to each other by forming the non-recessed portion in an arc shape, and a decrease in torque constant can be further suppressed.

  According to the invention of claim 14, the rotor and the stator can be arranged closer to each other.

  According to the fifteenth aspect of the present invention, it is possible to prevent the magnetic flux from rotating between the adjacent magnetic poles and reducing the amount of magnetic flux to the stator.

  According to the invention of claim 16, the stress acting on the rotor core is dispersed by the centrifugal force acting on the permanent magnet, and the durability of the rotor strength is improved.

  According to the invention of claim 17, the peak of the line voltage is leveled most.

It is a front view of the rotary electric machine of 1st Embodiment which concerns on this invention. (A) It is a principal part enlarged view of the rotary electric machine of 1st Embodiment, (b) is a principal part enlarged view of the conventional rotary electric machine. It is a graph which shows the analytical value of the relationship of the induced voltage with respect to an electrical angle, the line voltage, and magnetic flux density in the rotary electric machine of 1st Embodiment, and the conventional rotary electric machine. (A) is a graph which shows the actual value of the line voltage of each phase of the rotary electric machine of this embodiment, (b) is a graph which shows the actual value of the line voltage of each phase of the conventional rotary electric machine. It is a figure which shows the relationship between the shape of a rotor core, and a line voltage waveform. It is a flowchart explaining the flow at the time of determining the shape of the rotary electric machine of 1st Embodiment. It is a principal part enlarged view of the rotary electric machine of 2nd Embodiment. It is a graph which shows the relationship between the induced voltage with respect to the electrical angle, and the line voltage in the rotary electric machine of 2nd Embodiment. It is a flowchart explaining the flow at the time of determining the shape of the rotary electric machine of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
<First Embodiment>
As shown in FIGS. 1 and 2A, the rotating electrical machine 10 of this embodiment is an IPM type permanent magnet rotating electrical machine used as a traction motor of an electric vehicle, for example, and mainly rotates with the stator 11. And a child 20. The stator 11 includes a stator core 13 having a plurality of slots 14 and teeth 15 formed on the inner peripheral side of the laminated electromagnetic steel plates, and a plurality of stators 11 accommodated in the slots 14 to generate a rotating magnetic field and rotate the rotor 20. And a plurality of stator magnetic poles (18 in the present embodiment). The armature winding 16 has three phases (in this embodiment, U-phase, V-phase, and W-phase). In the rotating electrical machine 10 of the present embodiment, the tip of the tooth 15 is formed in an arc shape, and the armature winding 16 is wound around the tooth 15 with salient pole concentrated winding.

  The rotor 20 includes a substantially cylindrical rotor shaft (not shown), a rotor core 21 provided on the outer peripheral side thereof, and a plurality of magnetic pole portions 23, and a predetermined inner side in the radial direction of the stator 11. It arrange | positions so that rotation is possible through a clearance gap.

  The rotor core 21 is configured by laminating a plurality of electromagnetic steel plates 27 to 27 in the axial direction. Each of the electromagnetic steel plates 27 ... 27 has a hole 24 therein, and a pair of embedded holes 25, 25 in the circumferential direction in the vicinity of the outer peripheral surface 21a that is the stator facing surface of the rotor core 21 in the outer peripheral portion thereof. A plurality of substantially annular shapes are formed.

  The pair of embedded holes 25, 25 in the rotor core 21 are partitioned by a center rib 29 having a uniform width, and a permanent magnet 22a (22b) is disposed in each of them. The first magnetic pole portion 23A is constituted by two permanent magnets 22a and 22a having the same magnetization direction, and the second magnetic pole portion 23B is constituted by two permanent magnets 22b and 22b having different magnetization directions from the permanent magnets 22a and 22a. The one magnetic pole portion 23A and the second magnetic pole portion 23B are alternately arranged in the circumferential direction to constitute a plurality of rotor magnetic poles (12 in this embodiment).

  Each permanent magnet 22a (22b) has the same shape and has a substantially rectangular cross section. Each permanent magnet 22a (22b) is mounted so that there is no gap in the embedding hole 25, and in particular, the entire outer side surface of each permanent magnet 22a (22b) is in contact with the rotor core 21.

  Further, the rotor core 21 is formed with a groove 26 that divides the first magnetic pole part 23A and the second magnetic pole part 23B having different magnetization directions so as to be recessed radially inward from the outer peripheral surface 21a. The innermost diameter part (deepest part) of the groove part 26 is located radially inward from the outermost diameter part of the permanent magnet 22a (22b). A groove center line Q connecting the circumferential intermediate portion of the groove 26 and the rotation axis O of the rotor 20 forms a terminal end (magnetic pole end) of each magnetic pole, and between the groove center lines Q of adjacent groove parts 26 around the magnetic pole center P. Corresponds to 180 ° in electrical angle. The groove portion 26 functions as a magnetic flux short-circuit suppressing portion that prevents a magnetic flux short-circuit to the adjacent magnetic pole portion 23 by blocking the alternating magnetic flux from the magnetic poles of the permanent magnets 22a and 22b. In addition, the stress exerted on the rotor core 21 by the permanent magnet 22a (22b) due to the centrifugal force during rotation can be received at two locations of the minimum thickness portion 28 and the groove portion 26, and the stress is distributed and received. Become.

  Each magnetic pole portion 23A, 23B is formed with a convex portion 31 having an arc-shaped outer peripheral surface centering on the rotation axis O from a magnetic pole center P to a predetermined interval on both sides in the circumferential direction. A non-convex portion 41 having a tapered outer peripheral surface is formed over a predetermined section from both sides in the circumferential direction to the groove portion 26, and the outer diameter side of the rotor 20 is provided at the boundary between the convex portion 31 and the non-convex portion 41. One bending point 50 that is convex is formed.

  That is, the magnetic pole central part of each magnetic pole part 23A, 23B forms the convex part 31, and the magnetic pole end part on both sides in the circumferential direction sandwiching the magnetic pole central part forms the non-convex part 41. The inner peripheral surface of the stator 11 has a shape similar to the convex portion 31, the gap between the convex portion 31 is constant, and the gap between the inner peripheral surface of the stator 11 and the non-convex portion 41 is a bending point 50. As the groove portion 26 is approached, it increases. Here, when the magnetic pole end is viewed with respect to the magnetic pole center, the magnetic pole end becomes a concave portion, and the magnetic pole central portion becomes a non-recessed portion. Conversely, when the magnetic pole central portion is viewed with reference to the magnetic pole end, Becomes a convex part, and the magnetic pole end part becomes a non-convex part. Either the central part of the magnetic pole or the end part of the magnetic pole may be used as a reference, but in the following description, the central part of the magnetic pole is described as the convex part 31 and the magnetic pole end part is described as the non-convex part 41.

  The convex portion 31 has a rotor magnetic pole opening angle (opening angle between groove centerlines Q) of θ1 and a convex portion opening angle (opening angle between bending points 50) of θ2 around the magnetic pole center P, respectively. ) Θ1 <θ2 <(2/3) formed so as to satisfy θ1, and when the non-convex (concave) opening angle (opening angle between the bending point 50 and the groove center line Q) is θ3, the electrical angle is (1 / 6) It is formed so as to satisfy θ1 <θ3 <(5/18) θ1. More preferably, θ2 = (5/9) θ1 and θ3 = (2/9) θ1. In the present embodiment, θ1 = 180 °, θ2 = 100 °, and θ3 = 40 ° are set.

  Here, assuming that the rotor shown in FIG. 2B in which the outer peripheral surfaces of the magnetic pole portions 23A and 23B are formed only by an arc shape centered on the rotation axis O is a conventional rotating electric machine, as shown in FIG. In addition, the U-phase magnetic flux density of the present embodiment is higher than the conventional U-phase magnetic flux density in the vicinity of 90 ° and 270 ° in electrical angle, and accordingly, the U-phase induction of the present embodiment is increased. This embodiment is flat and low in the vicinity of 90 ° and 270 ° from the conventional U-phase induced voltage, and is the difference between the U-phase and V-phase induced voltages (U-phase induced voltage-V-phase induced voltage). The U-V line voltage of the embodiment has a lower peak than the conventional U-V line voltage and is flat.

  This is because the central portion of the magnetic pole forms the convex portion 31 and the magnetic pole end portion forms the non-convex portion 41, so that the magnet magnetic flux of the permanent magnet permanent magnet 22a (22b) is absorbed in the stator 11 as shown in FIG. This is because the convex portion 31 close to the peripheral surface can be concentrated, and the magnetic flux approaching the stator 11 can be accelerated by the convex portion 31. By abruptly entering the magnetic flux into the stator 11, there is an effect of adjusting the tertiary frequency component and the fifth frequency component in addition to the primary fundamental frequency in the induced voltage generated by the magnetic flux density fluctuation, and the torque constant is lowered. Each phase induced voltage derived from the equation (1) is adjusted without any adjustment. And the peak of the line voltage which is the difference of each phase induced voltage is reduced by adjusting each phase induced voltage, and the amplitude of a line voltage waveform can be suppressed.

[Formula 1]
V = n · d / dt · Φ · sinωt (1)
V: induced voltage, n: number of coil turns, Φ: magnetic flux density, ω: angular velocity, t: time

  3 shows only the U phase, the V phase and the W phase show the same tendency. The U-V line voltage, V-W line voltage, and W-U line voltage of this embodiment shown in FIG. 4A are all the U-V line of the conventional rotating electrical machine shown in FIG. 4B. Compared to the line voltage, the V-W line voltage, and the W-U line voltage, the peak is low and flat. In conventional rotating electrical machines, the line voltage peak exceeds the withstand voltage of the control circuit. On the other hand, in the rotating electrical machine 10 of this embodiment, the peak of the line voltage shows a value smaller than the withstand voltage of the control circuit.

Next, a procedure for determining the shape of the rotating electrical machine 10 of the present embodiment will be described with reference to FIG.
First, the outer diameter of the rotating electrical machine 10 is determined from the relationship between the mounting position of the vehicle and the space (step S11). Subsequently, the magnet position is determined based on the required torque of the vehicle (step S12). The permanent magnet 22a (22b) can output more torque as it is arranged on the outer peripheral side of the rotor core 21. Next, the wall thickness t (see FIG. 2A) of the minimum wall portion 28 is determined by the stress at the maximum rotation speed (step S13). Then, the bending point 50 is determined so that the convex portion 31 satisfies (4/9) θ1 <θ2 <(2/3) θ1 (step S14).

  As described above, in the rotating electrical machine 10 according to the present embodiment, the outer peripheral portion of the rotor 20 is formed with the convex portions 31 that protrude over the predetermined section in the circumferential direction at the magnetic pole portions 23A and 23B. 31 is formed so that the rotor magnetic pole opening angle is θ1 and the convex portion opening angle is θ2 around the magnetic pole center P, and the electrical angle satisfies (4/9) θ1 <θ2 <(2/3) θ1. As a result, the magnetic flux intrusion into the stator 11 can be made abrupt at the convex portion 31, and each phase induced voltage can be adjusted without lowering the torque constant. And the peak of the line voltage which is the difference of each phase induced voltage can be reduced by adjusting each phase induced voltage. Therefore, since a margin can be provided for the withstand voltage of the control circuit, the reliability can be improved. Alternatively, the motor constant can be improved and a high-performance rotating electrical machine can be obtained within a range that is less than or equal to the withstand voltage of the control circuit.

  Moreover, since the peak of the line voltage can be lowered only by changing the shape of the outer peripheral portion of each magnetic pole portion 23A, 23B, the shape of the magnet is not limited. In particular, by forming the permanent magnet 22a (22b) into a rectangular shape, the molding die can be used as it is, or even if machining such as cutting can be performed, the machining allowance can be reduced, and manufacturing can be performed at low cost. Further, since the molding material has a higher hardness as the molding surface, the possibility of magnet cracking can be reduced even when centrifugal force is applied, and the magnet strength and the rotor core strength are advantageous and the reliability is improved. Further, the permanent magnet 22a (22b) can be used regardless of the performance and size of the rotating electrical machine 10. Particularly in recent years, when manufacturing permanent magnets using precious rare earth materials, it is advantageous in terms of cost to secure a large amount of materials, and in terms of manufacturing, special dedicated equipment is required, but it greatly contributes to depreciation of the equipment.

  Further, since the entire side surface of the permanent magnet 22a (22b) is in contact with the rotor core 21, the magnetic flux can be transmitted to the rotor outer surface 21a without magnetic resistance, and a permanent material using an expensive rare earth material is used. The potential of the magnet can be fully utilized.

  In addition, since the groove portion 26 is provided between the magnetic pole portions 23A and 23B, the rotor core 21 contacts the corner of the embedded hole 25 near the corner of the permanent magnet 22a (22b) to which the centrifugal force has acted. Therefore, the bending moment arm can be made small, and further, stress can be received at two locations of the minimum thickness portion 28 and the groove portion 26, and the occurrence of stress concentration at one location can be suppressed.

  Further, by applying to the salient pole concentrated winding electric machine, the winding protruding from the rotor core 21 in the axial direction can be reduced, and the rotating electric machine can be downsized. Furthermore, there is an effect of reducing torque ripple, and the rotating electrical machine can be reduced in noise.

  Moreover, since the rotary electric machine 10 is an IPM type rotary electric machine, even when a centrifugal force is applied, the permanent magnet 22a (22b) can be easily held and can cope with high rotation.

<Second Embodiment>
Next, a rotating electrical machine according to a second embodiment of the present invention will be described with reference to FIG.
Each magnetic pole part 23A, 23B of the present embodiment is formed with a convex part 31 having an arc-shaped outer peripheral surface centering on the rotational axis O from a magnetic pole center P to a predetermined interval on both sides in the circumferential direction. A non-convex portion 42 having an outer peripheral surface having an arc shape smaller in diameter than the arc shape of the convex portion 31 is formed over a predetermined section from both circumferential sides of the groove 31 to the groove portion 26, and the boundary between the convex portion 31 and the non-convex portion 42 A first bending point 51 that protrudes from the outer diameter side of the rotor 20 and a second bending point 52 that protrudes from the inner diameter side of the rotor 20 are formed in each part. The first bending point 51 and the second bending point 52 are connected by a tapered surface 53.

  That is, the magnetic pole central part of each magnetic pole part 23A, 23B forms the convex part 31, the magnetic pole end part on both sides in the circumferential direction across the magnetic pole central part forms a non-convex part 42, and the inner peripheral surface of the stator 11 The gap with the convex portion 31 is constant, and the gap between the inner peripheral surface of the stator 11 and the non-convex portion 42 is increased as the taper surface 53 approaches the groove portion 26 side from the magnetic pole central portion side. 11 is constant in a gap larger than the gap between the inner peripheral surface 11 and the convex portion 31. In the present embodiment, the magnetic pole center portion is described as the convex portion 31 and the magnetic pole end portion is described as the non-convex portion 41. However, the magnetic pole end portion may be defined as a concave portion and the magnetic pole central portion may be defined as a non-recessed portion.

  The convex portion 31 has a rotor magnetic pole opening angle (opening angle between the groove center lines Q) as θ1 and a convex opening angle (opening angle between the first bending points 51) as θ2, respectively. / 9) θ1 <θ2 <(2/3) θ1 is formed so as to satisfy θ1, and the non-convex part (concave part) opening angle (the opening angle between the first bending point 51 and the groove part center line Q) is θ3. (1/6) θ1 <θ3 <(5/18) θ1 is satisfied. More preferably, θ2 = (5/9) θ1 and θ3 = (2/9) θ1. The first straight line R1 connecting the first bending point 51 and the rotational axis O of the rotor 20 and the second straight line R2 connecting the second bending point 52 and the rotational axis O of the rotor 20 are 1 ° in electrical angle. It's far away.

  FIG. 8 shows the U-phase induced voltage and the U-V line voltage in the second embodiment. Compared to the conventional rotating electrical machine shown in FIG. 3, the electrical angle is around 120 ° and 300 °. It can be seen that the peak of the U-V line voltage is low and flat.

Next, a procedure for determining the shape of the rotating electrical machine 10 of the present embodiment will be described with reference to FIG.
First, the outer diameter of the rotating electrical machine 10 is determined from the relationship between the mounting position of the vehicle and the space (step S21). Subsequently, the magnet position is determined based on the required torque of the vehicle (step S22). The permanent magnet 22a (22b) can output more torque as it is arranged on the outer peripheral side of the rotor core 21. Next, the thickness t of the minimum thickness portion 28 is determined based on the stress at the maximum rotation speed (step S23). Then, the first bending point 51 is determined so that the convex portion 31 satisfies (4/9) θ1 <θ2 <(2/3) θ1 (step S24). Subsequently, the second bending point 52 is determined at an electrical angle of 1 ° or more from the first bending point 52 (step S25).

  As described above, in the rotating electrical machine 10 according to the present embodiment, the boundary between the convex portion 31 and the non-convex portion 41 has the first bending point 51 in which the outer diameter side of the rotor 20 is convex, and the rotor 20. Even if it has the 2nd bending point 52 which makes the inner diameter side convex, similarly to the first embodiment, each phase induced voltage can be adjusted without reducing the torque constant. And the peak of the line voltage which is the difference of each phase induced voltage can be reduced by adjusting each phase induced voltage. Therefore, since a margin can be provided for the withstand voltage of the control circuit, the reliability can be improved. Alternatively, the motor constant can be improved and a high-performance rotating electrical machine can be obtained within a range that is less than or equal to the withstand voltage of the control circuit.

  Compared with the first embodiment, the line voltage moves up and down in the vicinity of the peak, and it can be said that the non-convex portion 41 is preferably tapered rather than arcuate. This is because the taper shape makes the flow of magnetic flux smoother and the waveform peak becomes flatter. From the viewpoint of circuit protection, it is more advantageous that the line voltage is flatter because the peak can be suppressed.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

DESCRIPTION OF SYMBOLS 10 Rotating electrical machine 11 Stator 16 Armature winding 20 Rotor 21 Rotor core 21a Outer peripheral surface 22a of rotor core Permanent magnet (permanent magnet part)
22b Permanent magnet (permanent magnet part)
23 magnetic pole part 23A first magnetic pole part 23B second magnetic pole part 26 groove part (magnetic flux short-circuit prevention part)
50 Bending Point 51 First Bending Point 52 Second Bending Point 31 Convex (non-concave)
41 Non-convex part (concave part)
θ1 Rotor magnetic pole opening angle θ2 Convex part opening angle θ3 Non-convex part opening angle (concave part opening angle)
O Rotational axis P Magnetic pole center

Claims (18)

A stator having a plurality of stator poles;
It has a rotor core and a plurality of permanent magnet portions that are arranged inside the rotor core and constitute magnetic poles, and are arranged to face each other through a predetermined gap in a radial direction inside the stator. A permanent magnet rotating electrical machine comprising a rotor,
On the outer peripheral portion of the rotor, a convex portion protruding over a predetermined section in the circumferential direction is formed on each magnetic pole,
The protrusions satisfy the electrical angle of (4/9) θ1 <θ2 <(2/3) θ1, where the rotor magnetic pole opening angle is θ1 and the protrusion opening angle is θ2, respectively. A permanent magnet type rotating electrical machine characterized by being formed. A non-convex portion that sandwiches the convex portion from both sides in the circumferential direction is formed on each magnetic pole on the outer peripheral portion of the rotor,
2. The permanent magnet type rotating electrical machine according to claim 1, wherein a boundary portion between the convex portion and the non-convex portion has one bending point that is convex toward the outer diameter side of the rotor. A non-convex portion that sandwiches the convex portion from both sides in the circumferential direction is formed on each magnetic pole on the outer peripheral portion of the rotor,
The boundary between the convex portion and the non-convex portion has a bending point that is convex on the outer diameter side of the rotor and a bending point that is convex on the inner diameter side of the rotor, respectively. The permanent magnet type rotating electric machine according to claim 1.   The permanent magnet type rotating electrical machine according to any one of claims 1 to 3, wherein an outer peripheral surface of the convex portion is formed in an arc shape centering on a rotation axis of the rotor.   The permanent magnet type rotating electrical machine according to claim 4, wherein an inner peripheral surface of the stator has a shape similar to an outer peripheral surface of the convex portion.   The permanent magnet type rotating electrical machine according to any one of claims 1 to 5, wherein a magnetic flux short-circuit prevention portion is formed between the magnetic poles adjacent to each other in the circumferential direction of the rotor. The magnetic flux short-circuit prevention portion is a groove portion that is recessed from the outer peripheral surface of the rotor,
The permanent magnet type rotating electrical machine according to claim 6, wherein the innermost diameter portion of the groove portion is located radially inside the outermost diameter portion of the permanent magnet portion.   The permanent magnet type rotating electric machine according to claim 1, wherein θ2 = (5/9) θ1.   The permanent magnet rotating electrical machine according to any one of claims 1 to 8, wherein a ratio of the number of magnetic poles of the stator to the number of magnetic poles of the rotor is 3: 2. A stator having a plurality of stator poles;
It has a rotor core and a plurality of permanent magnet portions that are arranged inside the rotor core and constitute magnetic poles, and are arranged to face each other through a predetermined gap in a radial direction inside the stator. A permanent magnet rotating electrical machine comprising a rotor,
On the outer periphery of the rotor, recesses that are recessed over a predetermined section in the circumferential direction are formed on both sides in the circumferential direction of each magnetic pole,
The recess has an electrical angle of (1/6) when the rotor magnetic pole opening angle is θ1 with respect to the magnetic pole center of the rotor and the recess opening angle from the rotor magnetic pole end side toward the magnetic pole center side is θ3. ) A permanent magnet type rotating electrical machine formed so as to satisfy θ1 <θ3 <(5/18) θ1. On the outer periphery of the rotor, non-recesses sandwiched between the recesses are formed in each magnetic pole,
11. The permanent magnet type rotating electrical machine according to claim 10, wherein a boundary portion between the non-recessed portion and the recessed portion has one bending point that protrudes from the outer diameter side of the rotor. On the outer periphery of the rotor, non-recesses sandwiched between the recesses are formed in each magnetic pole,
The boundary between the non-recessed portion and the recessed portion has a bending point that protrudes on the outer diameter side of the rotor and a bending point that protrudes on the inner diameter side of the rotor, respectively. Item 11. The permanent magnet type rotating electrical machine according to Item 10.   13. The permanent magnet type rotating electric machine according to claim 11, wherein an outer peripheral surface of the non-recess is formed in an arc shape centering on a rotation axis of the rotor.   The permanent magnet type rotating electrical machine according to claim 13, wherein an inner peripheral surface of the stator is formed in an arc shape having a larger diameter than an outer peripheral surface of the non-recessed portion.   The permanent magnet type rotating electrical machine according to any one of claims 10 to 14, wherein a magnetic flux short-circuit prevention portion is formed between the magnetic poles adjacent to each other in the circumferential direction of the rotor. The magnetic flux short-circuit prevention portion is a groove portion that is recessed from the outer peripheral surface of the rotor,
The permanent magnet type rotating electrical machine according to claim 15, wherein the innermost diameter portion of the groove portion is located radially inside the outermost diameter portion of the permanent magnet portion.   The permanent magnet type rotating electrical machine according to any one of claims 10 to 16, wherein θ3 = (2/9) θ1.   The permanent magnet rotating electrical machine according to any one of claims 10 to 17, wherein a ratio of the number of magnetic poles of the stator to the number of magnetic poles of the rotor is 3: 2.

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