JP2019054632A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine capable of improving cooling efficiency.SOLUTION: A rotary electric machine comprises: a stator that includes a housing with a cavity serving as a flow path, a rotor rotatably provided, a cylinder stator core in contact with an inner surface of the housing, and a coil that generates a magnetic field for rotating and driving the rotor; a leading line that is connected to a coil end of the coil and includes a connection terminal disposed outside the housing; a bus bar that is connected to the connection terminal and includes a first surface facing an outer surface of the housing; and an adhesion layer that has an electrical insulation. The first surface of the bus bar is fixed to the outer surface of the housing via the adhesion layer, and the outer surface of the stator core and the first surface of the bus bar are disposed opposite each other across the cavity.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a rotating electrical machine.

  Hybrid vehicles and electric vehicles are equipped with a drive rotating electrical machine capable of outputting high torque. When the rotating electrical machine is driven, heat is generated in the coil due to copper loss. In a water-cooled rotating electrical machine, heat generated by a coil is released to a coolant in a water channel provided inside the housing via a stator core and the housing. In particular, since the temperature tends to be highest at the coil end far from the stator core, a technique for cooling the coil end has been developed.

  For example, a technique is known in which a lead wire drawn from a coil end is distributed to both ends in the axial direction of a rotating electrical machine, and the lead wire is routed to the outside through a hole provided in a housing. Further, a device has been proposed in which the neutral point of the coil and the housing are in an electrically insulated state so as to be able to transfer heat.

JP 2010-28923 A JP 2012-196079 A

  Usually, the lead wire drawn out from the coil end is attached to the inside of the housing or the outside of the housing, and is connected to a terminal block having a built-in bus bar. However, with the two technologies described above, the configuration and routing of the leader line from the coil end to the terminal block may be complicated.

  The present invention has been made paying attention to these problems, and an object thereof is to provide a rotating electrical machine capable of improving the cooling efficiency.

  A rotating electrical machine according to an embodiment generates a housing having a cavity serving as a flow path, a rotor provided rotatably, a cylindrical stator core in contact with an inner surface of the housing, and a magnetic field that rotationally drives the rotor. A stator including a coil, a lead wire connected to a coil end of the coil and having a connection terminal disposed outside the housing, and a first surface connected to the connection terminal and facing the outer surface of the housing A bus bar having an electrical insulating property, and the first surface of the bus bar is fixed to the outer surface of the housing via the adhesive layer, and the outer surface of the stator core and the bus bar The first surface is disposed to face the cavity.

FIG. 1 is a perspective view showing a rotating electrical machine according to the present embodiment. FIG. 2 is a longitudinal sectional view of the rotating electrical machine shown in FIG. FIG. 3 is a cross-sectional view of the rotating electric machine taken along line I-I ′ of FIG. 2. FIG. 4 is a cross-sectional view of the rotating electric machine taken along line II-II ′ in FIG. 2. FIG. 5 is a cross-sectional view showing a terminal block portion of a rotating electrical machine according to another embodiment.

  Hereinafter, an embodiment and each modification of the present invention will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, for the sake of clarity, the drawings may be schematically represented with respect to the width, thickness, shape, etc. of each part as compared to actual aspects, but are merely examples, and The interpretation is not limited. In addition, in the present specification and each drawing, components that perform the same or similar functions as those described above with reference to the previous drawings are denoted by the same reference numerals, and repeated detailed description may be omitted as appropriate. .

  Hereinafter, the configuration of the rotating electrical machine according to the present embodiment will be described with reference to the drawings. In addition, although embodiment described below is not specifically limited, the rotary electric machine suitable for the drive of an electric vehicle or a hybrid vehicle is shown.

  FIG. 1 is a perspective view showing a rotating electrical machine 1 according to the present embodiment.

  As shown in FIG. 1, the rotating electrical machine 1 includes a housing 13 whose inside is sealed, and a terminal block 44 fixed to the outer surface of the housing 13. The terminal block 44 has a connection terminal for connecting a power source or a controller (not shown) to the rotating electrical machine 1. In the present embodiment, the terminal block 44 includes bus bars 9a, 9b, and 9c as three connection terminals corresponding to the U-phase, V-phase, and W-phase coils described later. The configuration of the terminal block 44 will be described later in detail.

  2 is a longitudinal sectional view of the rotating electrical machine 1, FIG. 3 is a transverse sectional view of the rotating electrical machine along the line II ′ in FIG. 2, and FIG. 4 is a rotation along the line II-II ′ in FIG. It is a cross-sectional view of an electric machine.

  As shown in FIGS. 1 and 2, the housing 13 includes a substantially cylindrical main body 131, a rear cover 132 that closes one end of the main body 131, and a front cover 133 that closes the other end of the main body 131. Have. The main body 131 and the front cover 133 may be integrally formed. The housing 13 has a refrigerant flow path 16 that is a cavity serving as a flow path for flowing the refrigerant in the wall portion of the main body 131. The refrigerant channel 16 extends over almost the entire circumference of the main body 131. Further, a refrigerant 19, for example, a supply pipe 16 a that supplies water, and a discharge pipe 16 b that discharges the refrigerant 19 that has flowed through the refrigerant flow path 16 are connected to the main body 131. The refrigerant 19 is cooled by a cooler (not shown), and is circulated through the refrigerant flow path 16 and the cooler by a pump (not shown). As the refrigerant 19, any coolant can be used as long as it is harmless to each member constituting the rotating electrical machine 1.

  As shown in FIGS. 2 and 4, the rotating electrical machine 1 includes a rotor 200, a bearing 4, a stator 500, a lead wire 7, and the like housed in a housing 13.

  The housing 13 has a protruding portion 13 a and a protruding portion 13 b that protrude in the axial direction of the rotating electrical machine 1 from the inner surfaces of the rear cover 132 and the front cover 133. The protruding portion 13 a and the protruding portion 13 b are formed in an annular shape and are provided coaxially with the main body 131. Here, the inner surface of the housing 13 is a surface facing a rotor core 3 and a stator core 5 described later.

  The rotor 200 includes a rotor shaft 2, a cylindrical rotor core 3 that is coaxially attached to the rotor shaft 2, and a plurality of permanent magnets 30 embedded in the rotor core 3. The rotor 200 is rotatably provided in the housing 13.

  The rotor shaft 2 extends coaxially with the main body 131 in the housing 13, and one end portion of the rotor shaft 2 extends through the front cover 133. The rotor shaft 2 is rotatably supported by the bearing 13 with respect to the housing 13. The bearing 4 is located between the protrusion 13 a and the rotor shaft 2 and between the protrusion 13 b and the rotor shaft 2.

  The rotor core 3 is fixed around the rotor shaft 2 and can rotate integrally with the rotor shaft 2. The rotor core 3 is composed of a large number of steel plates stacked in the axial direction of the rotor shaft 2. The permanent magnet 30 is embedded in the outer peripheral portion of the rotor core 3. Each permanent magnet 30 extends over the entire length of the rotor core 3. The plurality of permanent magnets 30 are arranged at a predetermined interval in the circumferential direction of the rotor core 3.

  The stator 500 includes a cylindrical stator core 5 and a coil 6 wound around the stator core 5. The stator core 5 is composed of a number of steel plates stacked in the axial direction of the rotor shaft 2. The stator core 5 is fitted and fixed to the inner peripheral surface of the main body 131 of the housing 13 by shrink fitting. That is, the outer surface S13 of the stator core 5 is in contact with the inner surface S11 of the housing 13. The stator core 5 is positioned coaxially with the rotor shaft 2 and the main body 131 and is disposed opposite to the outer periphery of the rotor core 3 with a gap GP. A plurality of slots extending in the axial direction are formed in the inner peripheral portion of the stator core 5, and the coil 6 is embedded in these slots. The coil 6 generates a magnetic field that rotationally drives the rotor 200. The rotating electrical machine 1 is a so-called multiphase AC motor such as a three-phase synchronous motor or a three-phase induction motor. For example, when the rotating electrical machine 1 is a three-phase synchronous motor, the coil 6 includes a U-phase coil, a V-phase coil, and a W-phase coil. The portions of the coil 6 that protrude from the stator core 5 on both sides in the axial direction form coil ends 6a.

  As shown in FIGS. 2 and 3, the lead wire 7 is drawn from the coil end 6a on the rear cover 132 side. The lead wire 7 includes a U-phase lead wire 7a, a V-phase lead wire 7b, and a W-phase lead wire 7c drawn from the U-phase coil, the V-phase coil, and the W-phase coil, respectively. These U-phase lead wire 7a, V-phase lead wire 7b, and W-phase lead wire 7c pass through the wall portion of the main body 131 and extend above the main body 131. Connection terminals 8 (U-phase terminal 8a, V-phase terminal 8b, and W-phase terminal 8c) are respectively crimped to the tips of the U-phase lead line 7a, V-phase lead line 7b, and W-phase lead line 7c. The connection terminal 8 is disposed outside the housing 13.

  As shown in FIGS. 1 and 2, the terminal block 44 includes bus bars 9a, 9b, and 9c and a case 10 molded with an insulating resin. Each of the bus bars 9a, 9b, 9c is formed in a long and narrow bar shape or plate shape with a highly conductive metal material such as copper or aluminum. The bus bars 9a, 9b, 9c are arranged in parallel with each other with a gap. As shown in FIG. 2, the bus bar 9 has a first surface S <b> 1 that faces the outer surface S <b> 12 of the housing 13. The first surface S1 is exposed from the case 10. One end portions of the bus bars 9a, 9b, and 9c are bent at right angles to form output terminal portions 41a, 41b, and 41c, respectively. Here, when the rotation axis direction of the rotor 200 is the first direction and the direction orthogonal to the first direction is the second direction, the output terminal portion 41 rises in the second direction. Of the output terminal portion 41, the second surface S2 exposed from the case 10 rises in the second direction. The second surface S2 does not overlap the refrigerant flow path 16 in the second direction. That is, the second surface S2 is separated from the refrigerant flow path 16 in the first direction. The bus bars 9a, 9b, and 9c have input terminal portions 42a, 42b, and 42c that are integrally provided in an intermediate portion, respectively.

  The output terminal portions 41a, 41b, and 41c are electrically connected to the connection terminals 8a, 8b, and 8c, respectively. The second surface S2 of the output terminal portion 41 is in contact with the surface 8S of the connection terminal 8. The connection terminals 8a, 8b, and 8c are electrically connected to the coil 6 disposed in the housing 13. In the illustrated example, the output terminal portions 41a, 41b, 41c are fixed by connection terminals 8a, 8b, 8c and bolts 17, respectively. The connection terminals 8a, 8b, and 8c and the bus bars 9a, 9b, and 9c may be fixed by at least one of bolt fixing, crimping, and welding.

  The insulating resin as the case 10 fills the terminal block 44 and covers the bus bar 9. Further, the case 10 is in contact with the thick portion 13c of the housing 13 in the first direction, and is also in contact with the outer surface of the thick portion 13c. The case 10 is fixed to the housing 13 by bolts 12 on the outer surface of the thick portion 13c. By covering the periphery of the bus bar 9 with the case 10, the insulation between the plurality of bus bars is maintained.

  As shown in FIG. 2, the first surface S <b> 1 of the bus bar 9 is fixed to the outer surface S <b> 12 of the housing 13 via the heat conductive adhesive layer 11. In other words, the heat conductive adhesive layer 11 is located between the first surface S1 and the outer surface S12 of the housing 13. The thermally conductive adhesive layer 11 has electrical insulation and thermal conductivity. Therefore, the electrical insulation between the bus bar 9 and the housing 13 can be maintained. Further, the thermal conductivity between the bus bar 9 and the housing 13 can be maintained.

  The rotating electrical machine 1 configured as described above generates an electromagnetic force by passing a current through the coil 6, and is driven by the electromagnetic force and the magnetic force of a permanent magnet existing in the rotor core 3. At this time, the coil 6 generates heat due to Joule heat. The heat generation of the rotating electrical machine 1 mainly results from copper loss and iron loss due to the electrical resistance of the coil 6. Some of these heat generations are released to the outside through the stator core 5 and the housing 13. However, the temperature rise of the coil 6 tends to be greatest at the coil end 6a having a long distance to the stator core 5, which is the main heat dissipation path.

  Next, the cooling structure of the rotating electrical machine 1 will be described. The cooling structure of the rotating electrical machine 1 according to the present embodiment releases heat generated from the coil 6 and the lead wire 7 to the refrigerant 19 filled in the refrigerant channel 16 by heat transfer of the structural member.

  The housing 13 has a coolant channel 16 formed in an annular shape outside the stator core 5. The outer surface S <b> 13 of the stator core 5 and the first surface S <b> 1 of the bus bar 9 are disposed so as to face each other through the refrigerant flow path 16. Therefore, in this embodiment, the heat generated in the coil 6 is radiated by the two heat radiation paths.

  As the first heat dissipation path, heat generated in the coil 6 is transferred in the order of the coil 6, the stator core 5, the housing 13, and the refrigerant flow path 16 to be radiated to the refrigerant 19 flowing through the refrigerant flow path 16. The coil 6 and the stator core 5 are in contact with each other through an insulating member in a state where heat can be transferred. The stator core 5 is in contact with the inner peripheral surface of the housing 13.

  As the second heat dissipation path, the heat generated in the coil 6 is transferred to the coil end 6a, the lead wire 7, the connection terminal 8, the bus bar 9, the housing 13, and the refrigerant flow path 16 in this order, and the refrigerant flowing through the refrigerant flow path 16 Heat is dissipated to 19. The coil end 6 a is in contact with the lead wire 7, and the lead wire 7 is in contact with the connection terminal 8. The connection terminal 8 is in contact with the bus bar 9. The lower surface of the bus bar 9 is in contact with the housing 13.

  The heat generated in the coil 6 and the lead wire 7 is released to the refrigerant 19 inside the refrigerant flow path 16 through the two heat dissipation paths.

  According to this embodiment, at least one surface of the bus bar 9 is bonded to the outer peripheral surface of the housing 13. Between the bus bar 9 and the housing 13, heat transfer can be performed while maintaining electrical insulation by the heat conductive adhesive layer. The bus bar 9 is in contact with the connection terminal 8 of the lead wire 7 drawn from the coil end 6a. Therefore, the heat generated at the coil end 6 a is conducted to the bus bar 9 through the lead wire 7 and is released from the bus bar 9 to the refrigerant 19 filled in the refrigerant flow path 16. Thereby, in addition to the heat dissipation path from the stator core 5 to the refrigerant flow path 16, the heat dissipation path through the lead wire 7 can be increased as a heat dissipation path for the heat generated from the coil end 6 a. Therefore, the cooling efficiency of the coil 6 and the coil end 6a can be improved with a simple cooling structure. In addition, it is possible to suppress the performance deterioration or failure of the rotating electrical machine 1 due to the temperature rise of the coil 6.

  FIG. 5 is a cross-sectional view showing a terminal block portion of a rotating electrical machine according to another embodiment. The terminal block 44 shown in FIG. 5 is different from the terminal block 44 shown in FIG. 2 in that the resin forming the case 10 is not filled in the terminal block 44 and surrounds the bus bar 9. . The case 10 is fixed to the housing 13 with bolts 12 in the same manner as shown in FIG.

  In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  The embodiment of the present invention is not limited to the above-described rotating electric machine, and can be applied to various rotating electric machines.

DESCRIPTION OF SYMBOLS 1 ... Rotary electric machine, 13 ... Housing, 4 ... Bearing
200 ... rotor, 2 ... rotor shaft, 3 ... rotor core,
500 ... Stator, 5 ... Stator core, 6 ... Coil, 6a ... Coil end,
8 ... Connection terminal, 7 ... Leader, 9 ... Bus bar,
16 ... Refrigerant flow path, 17 ... Bolt, 10 ... Case.

Claims (3)

A housing having a cavity serving as a flow path;
A rotor provided rotatably,
A stator comprising a cylindrical stator core in contact with the inner surface of the housing, and a coil that generates a magnetic field for rotationally driving the rotor;
A lead wire connected to a coil end of the coil and having a connection terminal disposed outside the housing;
A bus bar connected to the connection terminal and having a first surface facing the outer surface of the housing;
An adhesive layer having electrical insulation,
The first surface of the bus bar is fixed to the outer surface of the housing via the adhesive layer,
The rotating electrical machine, wherein an outer surface of the stator core and the first surface of the bus bar are disposed to face each other via the cavity. The bus bar has a second surface that rises in a second direction orthogonal to the first direction that is the rotation axis direction of the rotor;
2. The rotating electrical machine according to claim 1, wherein the second surface is separated from the cavity in the first direction and contacts the surface of the connection terminal. And a terminal block fixed to the outer surface of the housing.
The terminal block is
A plurality of the bus bars;
A mold resin covering the bus bar excluding the first surface and the second surface;
The rotating electrical machine according to claim 1, wherein the resin is fixed to the housing.

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