Rotating electric machine and drive device

Abstract

[PROBLEM] To provide a technology capable of improving a cooling effect. [SOLUTION] A rotating electric machine according to one aspect of the present disclosure includes: an annular stator yoke; a plurality of teeth; a coil; and a cooler. The plurality of teeth protrude radially inward or radially outward from the stator yoke. The coil is wound around the teeth. The cooler extends along the axial direction of the stator yoke between adjacent coils and contacts the coils.

Description

Rotating electric machine and drive unit

[0001] The present invention relates to a rotating electric machine and a drive device.

[0002] Japanese Patent Registration No. 6912028 discloses a motor system in which a flow path for circulating a refrigerant is provided inside a motor housing that houses the stator of the motor, and the stator is cooled by transferring heat from the stator to the refrigerant.

[0003] Japanese Patent Registration No. 6912028

[0004] The above-mentioned conventional techniques have room for further improvement in terms of improving the cooling effect.

[0005] The present disclosure provides a technique that can improve the cooling effect.

[0006] A rotating electric machine according to one aspect of the present disclosure includes an annular stator yoke, a plurality of teeth, a coil, and a cooler. The plurality of teeth protrude radially inward or outward from the stator yoke. The coil is wound around the teeth. The cooler extends along the axial direction of the stator yoke between adjacent coils and contacts the coil.

[0007] According to the present disclosure, the cooling effect can be improved.

[0008] FIG. 1 is a plan view of a drive device according to an embodiment. FIG. 2 is a cross-sectional view of a drive device according to an embodiment taken along line A-A' in FIG. 1. FIG. 3 is a perspective view showing a portion of a stator according to a first embodiment. FIG. 4 is a perspective view of a portion of the stator shown in FIG. 3 with the stator yoke and teeth removed. FIG. 5 is an end view of a portion of a stator tooth according to an embodiment. FIG. 6 is an end view of a portion of a stator before a coil according to a second embodiment is wound thereon. FIG. 7 is an end view of a portion of a stator after a coil according to the second embodiment has been wound thereon. FIG. 8 is a side view of a portion of a stator according to a third embodiment.

[0009] Hereinafter, a detailed description will be given of a mode for carrying out a drive device according to the present disclosure (hereinafter referred to as an "embodiment") with reference to the drawings. Note that the present disclosure is not limited to the embodiment. In the following embodiments, components having the same function are designated by the same reference numerals, and redundant description will be omitted.

[0010] In the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0011] The drive device 10 according to the embodiment is mounted, for example, on a vehicle (not shown). The vehicle on which the drive device 10 is mounted is, for example, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (EV), a fuel cell vehicle (FCV), or the like, which uses at least a rotating electric machine 20 as a power source. The drive device 10 is used as a power source for the above-mentioned vehicle.

[0012] For ease of understanding, each of the drawings referred to below shows an orthogonal coordinate system in which mutually perpendicular X-axis, Y-axis, and Z-axis directions are defined, with the positive Z-axis direction being the vertically upward direction.

[0013] In the following description, for convenience, the positive direction of the X axis is referred to as the forward direction, and the negative direction of the X axis is referred to as the rearward direction. Here, the forward direction refers to the direction in which the vehicle on which the drive unit is installed moves forward. The rearward direction refers to the direction in which the vehicle on which the drive unit is installed moves backward.

[0014] In the following description, the drive unit according to the present disclosure will be described as being mounted horizontally on a vehicle body that is stationary on a horizontal surface. However, the drive unit according to the present disclosure does not necessarily have to be mounted horizontally on the vehicle body.

[0015] Fig. 1 is a plan view of a drive device according to an embodiment. Fig. 2 is a cross-sectional view of the drive device 10 according to an embodiment taken along line A-A' in Fig. 1. The drive device 10 according to the present disclosure may be mounted on a vehicle body so that the front-to-rear direction is opposite to the mounting direction shown in Figs. 1 and 2. The drive device 10 according to the present disclosure may also be mounted on a vehicle body in a state rotated from the state shown in Figs. 1 and 2 around the Z axis.

[0016] 1 and 2, the rotating electric machine 20 includes a rotor 21 that can rotate about a rotation axis extending in the Y-axis direction, and a stator 22 that is positioned radially outward of the rotor 21. The rotating electric machine 20 rotates the rotation axis together with the rotor 21 by supplying a three-phase alternating current to the stator 22.

[0017] That is, the rotating electric machine 20 according to the embodiment is an inner rotor type motor in which the rotor 21 is disposed inside the stator 22. Note that in the present disclosure, the rotating electric machine 20 is not limited to being an inner rotor type motor, and may also be an outer rotor type motor.

[0018] The transmission mechanism 30 is provided, for example, on one axial side (+Y direction side) of the rotating electric machine 20. The transmission mechanism 30 includes a plurality of gears. The plurality of gears rotate the output shaft in conjunction with the rotation of the rotary shaft of the rotating electric machine 20.

[0019] That is, the transmission mechanism 30 has a plurality of gears and transmits the power of the rotating electric machine 20 to the output shaft. The output shaft outputs the power transmitted by the transmission mechanism 30 to the outside. The transmission mechanism 30 has a speed reduction function that reduces the rotational speed of the rotating electric machine 20 and increases the torque output from the rotating electric machine 20 in accordance with a reduction ratio, for example.

[0020] The rotating electric machine 20 generates heat when driven. Therefore, the rotating electric machine 20 according to the embodiment has a configuration for improving the cooling effect. Hereinafter, a configuration for cooling the stator 22 of the rotating electric machine 20 will be described with reference to FIGS. 3 to 8.

[0021] First, the stator according to the first embodiment will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is a perspective view showing a portion of the stator according to the first embodiment. Fig. 4 is a perspective view of the portion of the stator shown in Fig. 3 with the stator yoke and teeth removed. Fig. 5 is an end view of a portion of the stator teeth according to the embodiment. Note that Figs. 3 to 5 show the portion corresponding to the portion enclosed by the dashed line in Fig. 1.

[0022] 3, the stator includes a stator yoke 2, teeth 3, coils 4, and a cooler 5. A plurality of stator yokes 2 are arranged in a ring shape surrounding the rotor 21 (see FIG. 2).

[0023] The teeth 3 protrude radially inward from the stator yoke 2. Note that Fig. 3 illustrates first teeth 31, second teeth 32 adjacent to the first teeth 31 on one side of the first teeth 31, and third teeth 33 adjacent to the first teeth 31 on the other side of the first teeth 31.

[0024] The coils 4 are wound around each tooth. The coils 4 generate heat when current is applied during operation of the rotating electric machine 20. Therefore, as shown in Figures 4 and 5 , the coolers 5 are provided between adjacent coils 4 so as to extend along the axial direction (Y-axis direction) of the stator yoke 2 and come into contact with the coils 4.

[0025] The cooler 5 according to the first embodiment is disposed on the tooth 3 via the coil 4. Specifically, the cooler 5 according to the first embodiment is spirally wound around the coil 4 so as to go around the coil 4.

[0026] The cooler 5 is connected to a pump (not shown). The pump causes a refrigerant such as water to flow into the cooler 5, and the refrigerant flowing out of the cooler 5 is cooled by a cooling device such as a radiator, before flowing back into the cooler 5 and circulating.

[0027] In this way, the cooler 5 is in direct contact with the coil 4, which is the heat source, and therefore the cooling effect can be improved by efficiently transferring the heat generated from the coil 4 to the refrigerant circulating inside.

[0028] 5 , the cooler 5 includes a first portion 51, a second portion 52, and a third portion 53. The first portion 51 is located between the first teeth 31 and the second teeth 32. The second portion 52 is located between the first teeth 31 and the third teeth 33. The third portion 53 connects the first portion 51 and the second portion 52. The cooler 5 has insulating properties.

[0029] The first portion 51, the second portion 52, and the third portion 53 are in contact with the coil 4. This allows the cooler 5 to absorb heat from both side surfaces, which are the long sides of the coil 4, and from the entire end surfaces, which are the short sides of the coil 4, thereby improving the cooling effect.

[0030] 4 , the cooler 5 includes a winding portion 54, a first lead-out portion 55, and a second lead-out portion 56. The winding portion 54 is a portion wound around the tooth 3. The first lead-out portion 55 is connected to one of the starting point and the ending point of the winding portion 54. The second lead-out portion 56 is connected to the other of the starting point and the ending point of the winding portion 54.

[0031] The start and end points of the winding portion 54 are located at one of the two ends in the axial direction (Y-axis direction) of the stator yoke 2. This makes the cooler 5 easier to handle compared to a configuration in which the start and end points of the winding portion 54 are located at one end and the other end in the axial direction (Y-axis direction) of the stator yoke 2.

[0032] The cooler 5 is a tube through which a refrigerant circulates, and therefore the cooler 5 has a simple structure yet can improve the cooling effect.

[0033] Furthermore, the rotating electric machine 20 also generates heat from the rotor 21 when it is in operation. Therefore, the cooler 5 is configured so that the coolant flows in from a portion near the tip end of the teeth 3 and flows out from a portion near the base end of the teeth 3.

[0034] 3 and 4, the refrigerant flows into the cooler 5 from the first drawer 55 and flows out from the second drawer 56. In this way, the cooler 5 receives unheated refrigerant from the first drawer 55, which is closer to the rotor 21, the other heat source, out of the first drawer 55 and the second drawer 56, and therefore can cool the drive unit 10 more efficiently.

[0035] Furthermore, one end of the stator yoke 2 where the first lead portion 55 and the second lead portion 56 are arranged is the end opposite to the end of the stator yoke 2 from which the output shaft of the rotating electric machine 20 protrudes. This prevents the cooler 5 from interfering with the output shaft of the rotating electric machine 20.

[0036] Furthermore, the ends of the metal wires that make up the coil 4 are located at the end opposite to the end of the stator yoke 2 where the first lead-out portion 55 and the second lead-out portion 56 are located. This prevents the cooler 5 from interfering with the ends of the metal wires that make up the coil 4.

[0037] Next, a stator according to a second embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is an end view of a portion of the stator before the coil according to the second embodiment is wound. Fig. 7 is an end view of a portion of the stator after the coil according to the second embodiment is wound.

[0038] The cooler 5A according to the second embodiment is disposed in contact with the tooth 3. The coil 4A according to the second embodiment is wound around the tooth 3 via the cooler 5A. For example, as shown in Fig. 6 , the cooler 5A is wound spirally around the first tooth 31.

[0039] 7, the coil 4A is wound around the first teeth 31 from above the cooler 5A. This increases the contact area between the cooler 5A and the coil 4A, thereby further improving the cooling effect.

[0040] Next, a stator according to a third embodiment will be described with reference to Fig. 8. Fig. 8 is a side view of a portion of the stator according to the third embodiment. As shown in Fig. 8, the coil 4 and the cooler 5 according to the third embodiment are sealed with resin 6. This allows the rotating electric machine according to the third embodiment to more efficiently dissipate heat generated from the coil 4 to the outside by the resin 6.

[0041] Furthermore, the resin 6 that seals the coil 4 and the cooler 5 extends to the outside of the stator yoke 2. Specifically, the resin 6 is provided so as to protrude from both ends of the axial direction (Y-axis) of the stator yoke 2. This allows the resin 6 to conduct heat absorbed in the portion located inside the stator yoke 2 to the portion protruding outside the stator yoke 2 and dissipate the heat to the outside, thereby further improving the cooling effect.

[0042] Although the coolers 5 and 5A are tubes, the coolers 5 and 5A may be vapor chambers. By using a vapor chamber as the coolers 5 and 5A, the cooling effect can be further improved.

[0043] Furthermore, in the first to third embodiments, an example was given in which the coolers 5, 5A are wound spirally around the teeth 3, but the coolers 5, 5A in the embodiments do not necessarily have to be wound spirally.

[0044] For example, the cooler 5, 5A may be I-shaped in a plan view, inserted into the interior from one axial end of the stator yoke 2, contacting the coils 4, 4A within the stator yoke 2, and pulled out to the outside from the other axial end of the stator yoke 2.

[0045] In addition, the cooler 5, 5A may be configured to be inserted into the interior from one axial end of the stator yoke 2, wrap around the stator yoke 2 in a U-shape to contact the coils 4, 4A, and then be pulled out to the exterior from one axial end of the stator yoke 2.

[0046] The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. For example, the stator may be a stator core used in a rotating electrical machine having an outer rotor configuration, in which the radially outer end of the stator faces the rotor and the teeth protrude radially outward in the rotational direction.

[0047] The present technology may be configured as follows: (1) A rotating electric machine including: an annular stator yoke; a plurality of teeth protruding radially inward or outward from the stator yoke; coils wound around the teeth; and a cooler extending along the axial direction of the stator yoke between adjacent coils and in contact with the coils. (2) The plurality of teeth include first teeth, second teeth adjacent to the first teeth on one side of the first teeth, and third teeth adjacent to the first teeth on the other side of the first teeth, and the cooler includes first portions located between the first teeth and the second teeth, second portions located between the first teeth and the third teeth, and a third portion connecting the first portions and the second portions, and the first portions, the second portions, and the third portions are in contact with the coils. (3) The rotating electric machine according to (1) or (2), wherein the cooler is disposed on the tooth via the coil. (4) The rotating electric machine according to (1) or (2), wherein the cooler is disposed in contact with the tooth, and the coil is wound around the tooth via the cooler. (5) The rotating electric machine according to (3) or (4), wherein the cooler comprises a winding portion wound around the tooth, a first lead-out portion connected to one of a start point and an end point of the winding portion, and a second lead-out portion connected to the other of the start point and end point of the winding portion, and wherein the start point and the end point of the winding portion are located at one of both ends of the stator yoke in the axial direction. (6) The rotating electric machine according to any one of (1) to (5), wherein the cooler is a tube through which a refrigerant circulates. (7) The rotating electric machine according to (6), wherein the cooler flows in from a portion near the tip end of the teeth and flows out from a portion near the base end of the teeth. (8) The rotating electric machine according to any one of (5) to (7), wherein the one end of the stator yoke is an end of the stator yoke opposite to an end of the stator yoke from which an output shaft of the rotating electric machine protrudes.(9) The rotating electric machine according to any one of (5) to (8), wherein an end of a metal wire constituting the coil is located at an end of the stator yoke opposite to the one end. (10) The rotating electric machine according to (1) or (3), wherein the cooler is a vapor chamber. (11) The rotating electric machine according to any one of (1) to (10), wherein the coil and the cooler are sealed with resin. (12) The rotating electric machine according to (11), wherein the resin extends to the outside of the stator yoke. (13) A drive device comprising: a rotating electric machine including: an annular stator yoke; a plurality of teeth protruding radially inward or outward from the stator yoke; coils wound around the teeth; and a cooler extending along the axial direction of the stator yoke between adjacent coils and in contact with the coil; and a gear driven in conjunction with a rotating shaft of the rotating electric machine.

[0048] 2 Stator yoke 3 Teeth 4, 4A Coil 5, 5A Cooler 6 Resin 10 Drive device 20 Rotating electric machine 21 Rotor 22 Stator 30 Transmission mechanism 31 First teeth 32 Second teeth 33 Third teeth 51 First portion 52 Second portion 53 Third portion 54 Winding portion 55 First lead-out portion 56 Second lead-out portion

Claims

1. A rotating electric machine comprising: an annular stator yoke; a plurality of teeth protruding radially inward or outward from the stator yoke; coils wound around the teeth; and a cooler extending along the axial direction of the stator yoke between adjacent coils and in contact with the coils.

2. A rotating electric machine as described in claim 1, wherein the plurality of teeth include first teeth, second teeth adjacent to the first teeth on one side of the first teeth, and third teeth adjacent to the first teeth on the other side of the first teeth, and the cooler includes a first portion located between the first teeth and the second teeth, a second portion located between the first teeth and the third teeth, and a third portion connecting the first portion and the second portion, and the first portion, the second portion, and the third portion contact the coil.

3. A rotating electric machine according to claim 1, wherein the cooler is arranged on the teeth via the coil.

4. A rotating electric machine as claimed in claim 1, wherein the cooler is arranged in contact with the teeth, and the coil is wound around the teeth via the cooler.

5. A rotating electric machine as described in claim 3 or claim 4, wherein the cooler comprises a winding portion wound around the teeth, a first pull-out portion connected to one of the starting point and end point of the winding portion, and a second pull-out portion connected to the other of the starting point and end point of the winding portion, and the starting point and end point of the winding portion are located at one of the axial ends of the stator yoke.

6. The rotating electric machine according to claim 1, wherein the cooler is a tube through which a refrigerant circulates.

7. A rotating electric machine according to claim 6, wherein the cooler has a portion near the tip end of the teeth through which the coolant flows and a portion near the base end of the teeth through which the coolant flows.

8. A rotating electric machine according to claim 5, wherein the one end of the stator yoke is an end opposite to an end of the stator yoke from which an output shaft of the rotating electric machine protrudes.

9. A rotating electric machine according to claim 5, wherein an end of the metal wire constituting the coil is located at an end of the stator yoke opposite the one end.

10. The rotating electric machine according to claim 1, wherein the cooler is a vapor chamber.

11. The rotating electric machine according to claim 1, wherein the coil and the cooler are sealed with resin.

12. The rotating electric machine according to claim 11, wherein the resin extends to the outside of the stator yoke.

13. A drive unit comprising: a rotating electric machine comprising: a ring-shaped stator yoke; a plurality of teeth protruding radially inward or outward from the stator yoke; coils wound around the teeth; and a cooler extending along the axial direction of the stator yoke between adjacent coils and in contact with the coils; and a gear driven in conjunction with the rotating shaft of the rotating electric machine.

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