Motor unit

Abstract

To provide a technique capable of miniaturizing a motor unit.SOLUTION: A motor unit comprises: a stator that has a cylindrical shape having a center shaft as a center; a housing that has a peripheral wall holding the stator from an outside of a radial direction; at least one water path that is provided to a peripheral wall of the housing, is extended along a shaft direction that is parallel to the center shaft, and into which an aqueous coolant circulates; and at least one oil path that is provided to the peripheral wall of the housing, is extended along a shaft direction, and in which an oiliness coolant is circulated. At least the one water path and at least the one oil path are arranged along a peripheral direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to a motor unit.

Background Art

[0002] A motor unit is disclosed in Patent Document 1. This motor unit includes a stator having a cylindrical shape centered on a central axis, a housing having a peripheral wall that holds the stator from the outside in the radial direction, at least one water passage provided within the peripheral wall of the housing, each extending along an axial direction parallel to the central axis and through which an aqueous refrigerant flows, and at least one oil passage provided within the peripheral wall of the housing, each extending along the axial direction and through which an oily refrigerant flows.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor unit of Patent Document 1, the motor housed in the housing is cooled by an aqueous refrigerant flowing through the water passage and an oily refrigerant flowing through the oil passage. In this motor unit, the entire oil passage is arranged radially outside the water passage. It is desired to miniaturize the size of the motor unit.

[0005] This specification provides a technology capable of miniaturizing a motor unit.

Means for Solving the Problems

[0006] In a first aspect of the present technology, the motor unit may include a stator having a cylindrical shape centered on a central axis, a housing having a peripheral wall that holds the stator from the radially outer side, at least one water passage provided within the peripheral wall of the housing, each extending along an axial direction parallel to the central axis and through which an aqueous refrigerant flows, and at least one oil passage provided within the peripheral wall of the housing, each extending along the axial direction and through which an oily refrigerant flows. The at least one water passage and the at least one oil passage may be arranged along the circumferential direction.

[0007] According to the above configuration, at least one water passage and at least one oil passage are arranged side by side in the circumferential direction. Therefore, compared with a configuration in which the entire at least one oil passage is arranged radially outside the water passage, the range of the at least one oil passage that is arranged radially outside the water passage can be reduced. Accordingly, the motor unit can be miniaturized.

[0008] In a second aspect, in the first aspect, each of the at least one water passage may have the same cross-sectional shape perpendicular to the axial direction as each of the at least one oil passage.

[0009] In the case of a configuration in which the stator is held by the housing, it is desirable that the holding force in the circumferential direction of the housing is uniform. According to the above configuration, the rigidity of the housing can be made uniform at the location where at least one water passage is provided and at the location where at least one oil passage is provided. Accordingly, the holding force in the circumferential direction of the housing can be made uniform.

[0010] In a third aspect, in the second aspect, each of the at least one water passage may be at an equal distance from the central axis as each of the at least one oil passage.

[0011] According to the above configuration, the holding force in the circumferential direction of the housing can be made more uniform.

[0012] In the fourth aspect, in the third aspect described above, the at least one water channel and the at least one oil channel may be arranged at equal intervals in the circumferential direction.

[0013] According to the above configuration, the holding force in the circumferential direction of the housing can be made more uniform.

[0014] In the fifth aspect, in any one of the first to fourth aspects described above, each of the at least one water channels is isolated from the internal space of the housing that houses the stator, and each of the at least one oil channels may communicate with the internal space of the housing.

[0015] According to the above configuration, the stator in the housing can be cooled directly by an oil-based refrigerant inside the housing while being cooled from the outside in the radial direction by an aqueous refrigerant. In addition, the oil-based refrigerant supplied to the stator can also function as a lubricant.

[0016] In the sixth aspect, in the fifth aspect described above, the at least one oil channel may include a first oil channel located vertically below the central axis. At least one first opening may be provided in the peripheral wall of the housing to communicate between the internal space of the housing and the first oil channel.

[0017] The oil-based refrigerant supplied into the housing stays in the lower part of the internal space of the housing. At this time, if the first oil channel of the above configuration is provided, the oil-based refrigerant staying in the lower part of the internal space can be recovered and guided to other parts inside the housing or to the outside of the housing. Alternatively, an oil-based refrigerant can be supplied from the outside of the housing to the internal space of the housing using the first oil channel.

[0018] In the seventh aspect, in the sixth aspect described above, the at least one first opening may include a first inlet opening for introducing the oil-based refrigerant in the internal space of the housing into the first oil channel.

[0019] According to the above configuration, as described above, the oily refrigerant staying in the lower part of the internal space can be recovered and guided to other parts inside the housing or to the outside of the housing.

[0020] In the eighth aspect, in the seventh aspect, the at least one first opening may further include a first outlet opening that discharges the oily refrigerant in the first oil passage into the internal space of the housing or to the outside of the housing.

[0021] According to the above configuration, the oily refrigerant staying in the lower part of the internal space can be recovered and guided to other parts inside the housing or to the outside of the housing through the first inlet opening and the first outlet opening.

[0022] In the ninth aspect, in the eighth aspect, the first inlet opening may be located on one side in the axial direction with respect to one end face of the stator in the axial direction, and the first outlet opening may be located on the other side in the axial direction with respect to the other end face of the stator in the axial direction.

[0023] According to the above configuration, the oily refrigerant staying in the lower part of the space on one side can be recovered and guided to the space on the other side.

[0024] In the tenth aspect, in any one of the sixth to ninth aspects, the at least one oil passage may further include a second oil passage located vertically above the central axis. At least one second opening may be provided in the peripheral wall of the housing to communicate between the internal space of the housing and the second oil passage.

[0025] According to the above configuration, the oily refrigerant can be supplied to the stator through the second housing oil passage to directly cool the stator.

[0026] In the 11th aspect, in the above-mentioned 10th aspect, the second oil passage may be configured such that the oil-based refrigerant is supplied from the outside. The at least one second opening may include at least one second outlet opening that supplies the oil-based refrigerant in the second oil passage to the stator.

[0027] According to the above configuration, the relatively low-temperature oil-based refrigerant supplied from the outside can be supplied to the stator through the second housing oil passage to directly cool the stator.

[0028] In the 12th aspect, in the above-mentioned 11th aspect, the at least one second outlet opening may be directed toward the coil end of the stator.

[0029] The coil end of the stator is likely to generate heat. According to the above configuration, the oil-based refrigerant flowing out from the second outlet opening is supplied to the coil end. Therefore, the coil end can be directly cooled.

[0030] In the 13th aspect, in any one of the above-mentioned 1st to 12th aspects, the housing may include a central housing having the peripheral wall, a first cover connected to one end of the central housing in the axial direction, and a second cover connected to the other end of the central housing in the axial direction.

[0031] According to the above configuration, the central housing and the stator can be easily assembled as compared with the case where the housing is composed of two members.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0033] (First Embodiment) With reference to FIGS. 1 to 5, the drive device 2 of the first embodiment will be described. The drive device 2 is mounted on an electric vehicle or the like. The front-rear direction and the left-right direction in FIGS. 1 to 5 are provided for easy understanding of the description and do not define the actual direction. Hereinafter, based on the direction of viewing the drive device 2 from the rear, the "clockwise direction" and the "counterclockwise direction" will be described.

[0034] As shown in FIG. 1, the drive device 2 includes a gear unit 10, a motor unit 12, and an oil pump 14. The oil pump 14 is connected to an oil pan (not shown) provided below the motor unit 12 and the gear unit 10.

[0035] The gear unit 10 is provided in front of the motor unit 12. The gear unit 10 transmits the output from the motor unit 12 to a drive shaft (not shown). The gear unit 10 includes a gear housing 20, a first gear shaft 22, a second gear shaft 24, a first gear 26 fixed to the first gear shaft 22, and a second gear 28 fixed to the second gear shaft 24. In FIG. 1, only a part of the gear unit 10 is shown. That is, the gear unit 10 further includes gear shafts other than the first gear shaft 22 and the second gear shaft 24, gears other than the first gear 26 and the second gear 28, and the like. The first gear shaft 22 and the second gear shaft 24 extend along the front-rear direction. A first shaft oil passage 22A is formed in the first gear shaft 22. The rear end portion of the first gear shaft 22 is coupled to the front end portion of a motor shaft 40, which will be described later. The second gear 28 meshes with the first gear 26.

[0036] The motor unit 12 includes a motor housing 30 and a motor 32.

[0037] The motor 32 is housed in the internal space IS of the motor housing 30. The motor 32 includes a motor shaft 40, a rotor 42, and a stator 44. The motor shaft 40 extends along the axial direction A. The axial direction A is parallel to the front-rear direction. The motor shaft 40 is rotatably supported by the motor housing 30 by bearings. Formed in the motor shaft 40 are a second shaft oil passage 40A that penetrates the motor shaft 40 in the axial direction A, and a third shaft oil passage 40B that extends radially outward from the central portion of the second shaft oil passage 40A. The rotor 42 is fixed to the motor shaft 40. The stator 44 includes a stator core 46 and a coil 48. The stator core 46 has a cylindrical shape. The stator core 46 is composed of a plurality of electromagnetic steel sheets laminated in the axial direction A. The rotor 42 is disposed radially inside the stator core 46. The coil 48 is wound around the stator core 46. The stator core 46 has a rear surface 46A and a front surface 46B. From the rear surface 46A, the rear coil end 48A of the coil 48 protrudes rearward. From the front surface 46B, the front coil end 48B of the coil 48 protrudes forward. The stator 44 is fixed to the motor housing 30 by shrink fitting or the like. The outer peripheral wall of the stator core 46 abuts against the inner peripheral wall of the motor housing 30. By the stator 44, the internal space IS of the motor housing 30 is separated into a rear space RS behind the stator 44 and a front space FS in front of the stator 44.

[0038] The motor housing 30 includes a central housing 50, a front cover 52, and a rear cover 54. The central housing 50 has a cylindrical shape. The central housing 50 extends along the axial direction A. Both the front and rear ends of the central housing 50 are open. The central housing 50 holds the stator 44 from the outside in the radial direction.

[0039] As shown in FIG. 2, the central housing 50 has a peripheral wall 50A having a cylindrical shape. The central axis coincides with axis A. The peripheral wall 50A can also be said to be the peripheral wall of the motor housing 30. In the central housing 50, a plurality of axial water channels 56A to 56F and a first housing oil passage 58 are formed. In FIG. 2, for the sake of clarity, the first housing oil passage 58 is shown in thick lines. Also, hereinafter, the plurality of axial water channels 56A to 56F may be collectively referred to as "axial water channel 56". The axial water channel 56 and the first housing oil passage 58 extend along the direction of axis A. The axial water channel 56 and the first housing oil passage 58 are arranged along the circumferential direction. The axial water channel 56A and the first housing oil passage 58 are arranged at equal intervals in the circumferential direction. The first housing oil passage 58 is located vertically below axis A. The first housing oil passage 58 is arranged between the axial water channel 56A and the axial water channel 56F in the circumferential direction. The axial water channel 56 and the first housing oil passage 58 have the same cross-sectional shape perpendicular to the direction of axis A. Specifically, the axial water channel 56A and the first housing oil passage 58 have the same radial length and circumferential length. The axial water channel 56 is at an equal distance from the first housing oil passage 58 and axis A. The axial water channel 56 penetrates the central housing 50 in the front-rear direction. That is, the axial water channel 56 is isolated from the internal space IS of the motor housing 30.

[0040] As shown in FIG. 1, a lower opening 60 that communicates the internal space IS of the motor housing 30 and the first housing oil passage 58 is provided in the peripheral wall 50A of the central housing 50. The lower opening 60 includes a lower inlet opening 62 located on the rear side of the stator 44 and a lower outlet opening 64 located on the front side of the stator 44. The lower inlet opening 62 is provided in the rear space RS of the motor housing 30 and communicates the rear space RS of the motor housing 30 and the first housing oil passage 58. The lower inlet opening 62 introduces the oil in the rear space RS of the motor housing 30 into the first housing oil passage 58. The lower inlet opening 62 is provided at a position adjacent to the rear surface 46A (one end surface in the axial direction of the shaft A) of the stator core 46 in the axial direction of the shaft A. Specifically, the lower inlet opening 62 is provided in the range from the rear end of the central housing 50 to the rear end surface of the stator core 46. The lower outlet opening 64 is provided in the front space FS of the motor housing 30 and communicates the front space FS of the motor housing 30 and the first housing oil passage 58. The lower outlet opening 64 discharges the oil in the first housing oil passage 58 into the front space FS of the motor housing 30. The lower outlet opening 64 is provided at the front end portion of the central housing 50. That is, the lower outlet opening 64 is provided on the front side (the other side) of the front surface 46B (the other end surface in the axial direction of the shaft A) of the stator core 46 in the axial direction of the shaft A.

[0041] As shown in FIG. 3, the front cover 52 is formed with a supply water passage 70 having a water supply port 70A, a discharge water passage 72 having a water discharge port 72A, and a plurality of front circumferential water passages 74A to 74D. Hereinafter, the plurality of front circumferential water passages 74A to 74D may be collectively referred to as the "front circumferential water passage 74". The front circumferential water passages 74 are arranged along the circumferential direction. The front circumferential water passages 74 extend along the circumferential direction. The supply water passage 70 is connected to the front circumferential water passage 74A. The discharge water passage 72 is connected to the front circumferential water passage 74D. An axial water passage 56A (see FIG. 2) is connected to the front circumferential water passage 74A. An axial water passage 56B (see FIG. 2) is connected to the end portion of the front circumferential water passage 74B on the clockwise side, and an axial water passage 56C (see FIG. 2) is connected to the end portion on the counterclockwise side. An axial water passage 56D (see FIG. 2) is connected to the end portion of the front circumferential water passage 74C on the clockwise side, and an axial water passage 56E (see FIG. 2) is connected to the end portion on the counterclockwise side. An axial water passage 56F (see FIG. 2) is connected to the front circumferential water passage 74D.

[0042] As shown in FIG. 1, the front cover 52 and the gear housing 20 are integrally formed. A second housing oil passage 68 that communicates the front space FS of the motor housing 30 and the inner space of the gear housing 20 is formed in the front cover 52 and the gear housing 20.

[0043] As shown in FIG. 4, a plurality of rear circumferential water channels 84A to 84C are formed in the rear cover 54. Hereinafter, the plurality of rear circumferential water channels 84A to 84C may be collectively referred to as the "rear circumferential water channel 84". The rear circumferential water channels 84 are arranged along the circumferential direction. The rear circumferential water channels 84 extend along the circumferential direction. An axial water channel 56A (see FIG. 2) is connected to the end portion on the clockwise side of the rear circumferential water channel 84A, and an axial water channel 56B (see FIG. 2) is connected to the end portion on the counterclockwise side. An axial water channel 56C (see FIG. 2) is connected to the end portion on the clockwise side of the rear circumferential water channel 84B, and an axial water channel 56D (see FIG. 2) is connected to the end portion on the counterclockwise side. An axial water channel 56E (see FIG. 2) is connected to the end portion on the clockwise side of the rear circumferential water channel 84C, and an axial water channel 56F (see FIG. 2) is connected to the end portion on the counterclockwise side.

[0044] A high-voltage current flows through the coil 48 of the stator 44 in FIG. 1. Therefore, the stator 44 generates heat. In this embodiment, the stator 44 is cooled by using cooling water and oil. A configuration for cooling the stator 44 by using cooling water and oil will be described.

[0045] First, a configuration in which the stator 44 is cooled by using a refrigerant will be described. In this embodiment, a single water system that connects the supply water channel 70 and the discharge water channel 72 of the front cover 52 is formed by the front circumferential water channel 74 (see FIG. 3) of the front cover 52, the axial water channel 56 (see FIG. 2) of the central housing 50, and the rear circumferential water channel 84 (see FIG. 4) of the rear cover 54. The axial water channel 56 of the central housing 50 is provided on the radially outer side of the stator 44. Therefore, the stator 44 is cooled by the flow of cooling water in the axial water channel 56F.

[0046] Next, with reference to FIG. 5, a configuration for cooling the stator 44 using oil will be described. Note that the arrows in FIG. 5 indicate the direction in which the oil flows. Also, in FIG. 5, for the sake of easy viewing of the oil flow direction, the reference numerals of some members are omitted, and the flow paths of the second shaft oil passage 40A, the third shaft oil passage 40B, the first housing oil passage 58, and the second housing oil passage 68 are shown larger than in FIG. 1. Further, hereinafter, for the sake of easy understanding, the oil flow in the state where the motor shaft 40 is stopped will be described as an example.

[0047] As described above, the oil stored in the oil pan of the gear unit 10 is supplied to the second shaft oil passage 40A of the motor shaft 40 by the oil pump 14. The oil flowing into the second shaft oil passage 40A flows forward through the second shaft oil passage 40A. When the oil flowing into the second shaft oil passage 40A reaches the central portion of the second shaft oil passage 40A, a part of the oil flows toward the third shaft oil passage 40B, and the remaining oil flows further forward. The oil flowing further forward flows into the first shaft oil passage 22A (see FIG. 1) of the first gear shaft 22. On the other hand, the oil flowing toward the third shaft oil passage 40B passes through the third shaft oil passage 40B. A part of the oil reaching the rotor 42 flows backward, and the remaining oil flows forward. Then, the oil flowing out of the rotor 42 flows downward. In the process of the oil flowing downward, the oil contacts the rear coil end 48A and the front coil end 48B of the stator 44. Thereby, the rear coil end 48A and the front coil end 48B of the stator 44 are cooled.

[0048] Note that the oil flowing out of the rotor 42 stays in the lower parts of the rear space RS and the front space FS of the motor housing 30. Since the rear space RS and the front space FS communicate with each other via the first housing oil passage 58, the oil staying in the lower part of the rear space RS flows into the front space FS via the first housing oil passage 58. Then, the oil staying in the lower part of the front space FS passes through the second housing oil passage 68 and flows into the gear housing 20.

[0049] As described above, as shown in FIG. 1, the motor unit 12 includes a stator 44 having a cylindrical shape centered on the axis A, a motor housing 30 (an example of a "housing") having a peripheral wall 50A that holds the stator 44 from the radially outer side, an axial water passage 56 (an example of "at least one water passage") provided within the peripheral wall 50A of the motor housing 30, each extending along the direction of the axis A parallel to the central axis and through which cooling water (an example of "aqueous refrigerant") flows, and a first housing oil passage 58 (an example of "at least one oil passage") provided within the peripheral wall 50A of the motor housing 30, each extending along the direction of the axis A and through which oil (an example of "oil-based refrigerant") flows. As shown in FIG. 2, the axial water passage 56 and the first housing oil passage 58 are arranged along the circumferential direction.

[0050] According to the above configuration, the axial water passage 56 and the first housing oil passage 58 are arranged side by side in the circumferential direction. Therefore, compared with a configuration in which the entire first housing oil passage 58 is arranged radially outside the axial water passage 56, the range of the first housing oil passage 58 that is arranged radially outside the axial water passage 56 can be reduced. Thus, the motor unit 12 can be miniaturized.

[0051] Also, as shown in FIG. 2, each of the axial water passages 56 has the same cross-sectional shape perpendicular to the axis A as the first housing oil passage 58.

[0052] In the case of a configuration in which the stator 44 is held by the motor housing 30, it is desirable that the holding force in the circumferential direction of the motor housing 30 be uniform. According to the above configuration, the rigidity of the motor housing 30 can be made uniform at the location where the axial water passage 56 is provided and at the location where the first housing oil passage 58 is provided. Therefore, the holding force in the circumferential direction of the motor housing 30 can be made uniform.

[0053] Also, as shown in FIG. 2, each of the axial water passages 56 is at an equal distance from the central axis as the first housing oil passage 58.

[0054] According to the above configuration, the holding force in the circumferential direction of the motor housing 30 can be made more uniform.

[0055] Also, as shown in FIG. 2, the axial water passages 56 and the first housing oil passages 58 are arranged at equal intervals in the circumferential direction.

[0056] According to the above configuration, the holding force in the circumferential direction of the motor housing 30 can be made even more uniform.

[0057] Also, as shown in FIG. 1, each of the axial water passages 56 is isolated from the internal space IS of the motor housing 30 that houses the stator 44, and the first housing oil passages 58 communicate with the internal space IS of the motor housing 30.

[0058] According to the above configuration, the stator 44 in the motor housing 30 can be cooled directly by oil inside the motor housing 30 while being cooled from the outside in the radial direction by cooling water. In addition, the oil supplied to the stator 44 can also function as a lubricant.

[0059] Also, as shown in FIG. 1, the first housing oil passages 58 (an example of the "first oil passages") are located vertically below the central axis. On the circumferential wall 50A of the motor housing 30, a lower opening 60 (an example of the "at least one first opening") that communicates between the internal space IS of the motor housing 30 and the first housing oil passages 58 is provided.

[0060] The oil supplied into the motor housing 30 stays in the lower part of the internal space IS of the motor housing 30. At this time, when the first housing oil passages 58 are provided, the oil staying in the lower part of the internal space IS can be recovered and guided to other parts inside the motor housing 30.

[0061] Also, as shown in FIG. 1, the lower opening 60 includes a lower inlet opening 62 (an example of a "first inlet opening") that introduces oil in the internal space IS of the motor housing 30 into the first housing oil passage 58.

[0062] According to the above configuration, the oil staying in the lower part of the internal space IS can be recovered and guided to other parts in the motor housing 30.

[0063] Also, as shown in FIG. 1, the lower opening 60 further includes a lower outlet opening 64 (an example of a "second outlet opening") that discharges the oil in the first housing oil passage 58 into the front space FS of the motor housing 30.

[0064] According to the above configuration, the oil staying in the lower part of the rear space RS can be recovered and guided to the front space FS in the motor housing 30 through the lower inlet opening 62 and the lower outlet opening 64.

[0065] Also, the lower inlet opening 62 is located on the rear side (an example of "one axial side") with respect to the rear end face of the stator 44 (specifically, the rear surface 46A of the stator core 46) (an example of "one axial side end face"), and the lower outlet opening 64 is located on the front side (an example of "the other axial side") with respect to the front end face of the stator 44 (specifically, the front surface 46B of the stator core 46) (an example of "the other axial side end face").

[0066] According to the above configuration, the oil staying in the lower part of the rear space RS can be recovered and guided to the front space FS.

[0067] Also, the motor housing 30 includes a central housing 50 having a peripheral wall 50A, a front cover 52 (an example of a "first cover") connected to the front end portion (an example of "one end portion") of the central housing 50, and a rear cover 54 (an example of a "second cover") connected to the rear end portion (an example of "the other end portion") of the central housing 50.

[0068] According to the above configuration, the central housing 50 and the stator 44 can be easily assembled as compared with the case where the motor housing 30 is composed of two members.

[0069] (Second Embodiment) Referring to FIGS. 6 and 7, the drive device 202 of the second embodiment will be described. For the components common to the embodiments, the same reference numerals are given and the description thereof is omitted.

[0070] As shown in FIG. 7, in the central housing 250 of the motor housing 30, a plurality of axial water passages 56A to 56F, a first housing oil passage 58, and a third housing oil passage 260 are formed. The third housing oil passage 260 is located vertically above the shaft A. The third housing oil passage 260 is disposed between the axial water passage 56C and the axial water passage 56D in the circumferential direction. As shown in FIG. 6, an oil inlet opening 262 is provided at the upper part of the rear end of the rear cover 54. An upper opening 264 that communicates the internal space IS of the motor housing 30 and the third housing oil passage 260 is provided in the central peripheral wall 250A of the central housing 250. The upper opening 264 includes a rear oil outlet opening 266 and a front oil outlet opening 268. The rear oil outlet opening 266 is provided above the rear coil end 48A of the stator 44. The front oil outlet opening 268 is provided above the front coil end 48B of the stator 44. The rear oil outlet opening 266 and the front oil outlet opening 268 are respectively directed to the rear coil end 48A and the front coil end 48B. The third housing oil passage 260 includes an axial oil passage 270, a rear radial oil passage 272, and a front radial oil passage 274. The axial oil passage 270 extends from the oil inlet opening 262 to in front of the rear end of the central housing 250. The rear radial oil passage 272 communicates the axial oil passage 270 and the rear oil outlet opening 266. The front radial oil passage 274 communicates the axial oil passage 270 and the front oil outlet opening 268.

[0071] Although illustration is omitted, circumferential water channels that constitute a first water system including axial water channels 56A to 56C and circumferential water channels that constitute a second water system including axial water channels 56D to 56F are formed in the front cover 252 and the rear cover 254 of the present embodiment.

[0072] As described above, as shown in FIG. 7, the motor unit 12 further includes a third housing oil passage 260 (an example of the "second oil passage") located vertically above the axis A. An upper opening 264 (an example of the "at least one second opening") that communicates between the internal space IS of the motor housing 30 and the third housing oil passage 260 is provided in the peripheral wall 50A of the motor housing 30.

[0073] According to the above configuration, oil can be supplied to the stator 44 through the upper opening 264 to directly cool the stator 44.

[0074] Also, as shown in FIG. 6, the third housing oil passage 260 is configured to be supplied with oil from the outside. The upper opening 264 includes a rear oil outlet opening 266 and a front oil outlet opening 268 (an example of the "at least one second outlet opening") that supply the oil in the third housing oil passage 260 to the stator 44.

[0075] According to the above configuration, relatively low-temperature oil supplied from the outside can be supplied to the stator 44 through the third housing oil passage 260 to directly cool the stator 44.

[0076] Also, as shown in FIG. 6, each of the rear oil outlet opening 266 and the front oil outlet opening 268 is directed toward the rear coil end 48A and the front coil end 48B of the stator 44.

[0077] The rear coil end 48A and the front coil end 48B of the stator 44 are prone to heat generation. According to the above configuration, the oil flowing out from the rear oil outlet opening 266 and the front oil outlet opening 268 is supplied to the rear coil end 48A and the front coil end 48B. Therefore, the rear coil end 48A and the front coil end 48B can be directly cooled.

[0078] As described above, specific examples of the technology disclosed in this specification have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

[0079] (First Modified Example) In the first embodiment, the cross-sectional shape of the axial water passage 56 and the cross-sectional shape of the first housing oil passage 58 may be different. Also, the axial water passage 56 may be at a different distance from the first housing oil passage 58 with respect to the axis A. Furthermore, the axial water passage 56 and the first housing oil passage 58 may not be arranged at equal intervals in the circumferential direction.

[0080] (Second Modified Example) In the first and second embodiments, the first housing oil passage 58 may be isolated from the internal space IS of the motor housing 30. That is, the lower opening 60 may not be provided in the central housings 50, 250. In this case, it is preferable that an oil passage communicating the rear end of the first housing oil passage 58 with the outside (specifically, the inner space of the gear housing 20) is provided in the front covers 52, 252, and an oil passage communicating the rear end of the first housing oil passage 58 with the rear space RS is provided in the rear covers 54, 254.

[0081] (Third Modification Example) In the first and second embodiments, the central housings 50 and 250 may not include either the lower inlet opening 62 or the lower outlet opening 64. When the central housings 50 and 250 do not include the lower inlet opening 62, an oil passage communicating the rear end of the first housing oil passage 58 with the rear space RS may be provided in the rear covers 54 and 254. Further, when the central housings 50 and 250 do not include the lower outlet opening 64, an oil passage communicating the front end of the first housing oil passage 58 with the outside may be provided in the front covers 52 and 252.

[0082] (Fourth Modification Example) In the first and second embodiments, the position where the first housing oil passage 58 is provided is not limited to directly below the axis A. The first housing oil passage 58 may be located below the axis A.

[0083] (Fifth Modification Example) In the second embodiment, the motor unit 12 may not include the first housing oil passage 58 and may include a third housing oil passage 260. In this modification example, the third housing oil passage 260 is an example of the "first oil passage".

[0084] (Sixth Modification Example) In the second embodiment, the position where the third housing oil passage 260 is provided is not limited to directly above the axis A. The third housing oil passage 260 may be located above the lower ends of the rear coil end 48A and the front coil end 48B. In another modification example, the third housing oil passage 260 may be located below the lower ends of the rear coil end 48A and the front coil end 48B.

[0085] (Seventh Modification Example) In the first embodiment, the motor unit 12 may further include one or more oil passages having the same configuration as the first housing oil passage 58.

[0086] (Eighth Modification Example) In the second embodiment, the central housing 250 may include only one of the rear oil outlet opening 266 and the front oil outlet opening 268.

[0087] (9th Modification Example) In the second embodiment, the rear oil outlet opening 266 and the front oil outlet opening 268 may not be respectively directed to the rear coil end 48A and the front coil end 48B. For example, the rear oil outlet opening 266 and the front oil outlet opening 268 may be directed to the stator core 46.

[0088] (10th Modification Example) The motor housing 30 may be composed of two members.

[0089] (11th Modification Example) The motor housing 30 may include a water channel that branches from one inflow channel and flows in the clockwise direction and a water channel that flows in the counterclockwise direction.

[0090] Also, the technical elements described in this specification or the drawings exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies exemplified in this specification or the drawings can achieve multiple objectives simultaneously, and achieving one of these objectives itself has technical utility.

Description of Reference Numerals

[0091] 2: Drive device, 10: Gear unit, 12: Motor unit, 14: Oil pump, 20: Gear housing, 22: First gear shaft, 22A: First shaft oil passage, 24: Second gear shaft, 26: First gear, 28: Second gear, 30: Motor housing, 32: Motor, 40: Motor shaft, 40A: Second shaft oil passage, 40B: Third shaft oil passage, 42: Rotor, 44: Stator, 46: Stator core, 46A: Rear surface, 46B: Front surface, 48: Coil, 48A: Rear coil end, 48B: Front coil end, 50: Central housing, 50A: Peripheral wall, 52: Front cover, 54: Rear cover, 56: Axial water passage, 58: First housing oil passage, 60: Lower opening, 62: Lower inlet opening, 64: Lower outlet opening, 68: Second housing oil passage, 70: Supply water passage, 70A: Water supply port, 72: Discharge water passage, 72A: Water discharge port, 74: Front circumferential water passage, 84: Rear circumferential water passage, 202: Drive device, 250: Central housing, 250A: Central peripheral wall, 252: Front cover, 254: Rear cover, 260: Third housing oil passage, 262: Oil inlet opening, 264: Upper opening, 266: Rear oil outlet opening, 268: Front oil outlet opening, 270: Axial oil passage, 272: Rear radial oil passage, 274: Front radial oil passage, A: Shaft, FS: Front space, IS: Internal space, RS: Rear space

Claims

1. A stator having a cylindrical shape centered on a central axis, A housing having a peripheral wall that holds the stator from the outside in the radial direction, At least one water passage provided within the peripheral wall of the housing, each extending along an axial direction parallel to the central axis and through which an aqueous refrigerant flows, At least one oil passage provided within the peripheral wall of the housing, each extending along the axial direction and through which an oily refrigerant flows, Comprising, The at least one water passage and the at least one oil passage are arranged along the circumferential direction, A motor unit.

2. Each of the at least one water passage has the same cross-sectional shape perpendicular to the axial direction as each of the at least one oil passage, the motor unit according to claim 1.

3. Each of the at least one water passage is at an equal distance from the central axis as each of the at least one oil passage, the motor unit according to claim 2.

4. The at least one water passage and the at least one oil passage are arranged at equal intervals in the circumferential direction, the motor unit according to claim 3.

5. Each of the at least one water passage is isolated from the internal space of the housing that houses the stator, Each of the at least one oil passage communicates with the internal space of the housing, the motor unit according to claim 1.

6. The at least one oil passage includes a first oil passage located vertically below the central axis, At least one first opening is provided in the peripheral wall of the housing to communicate between the internal space of the housing and the first oil passage, the motor unit according to claim 5.

7. The at least one first opening includes a first inlet opening that introduces the oily refrigerant within the internal space of the housing into the first oil passage, the motor unit according to claim 6.

8. The at least one first opening further includes a first outlet opening that discharges the oily refrigerant within the first oil passage into the internal space of the housing or to the outside of the housing, the motor unit according to claim 7.

9. The first inlet opening is located on one side in the axial direction relative to one end face of the stator in the axial direction, The motor unit according to claim 8, wherein the first outlet opening is located on the other side in the axial direction with respect to the other end surface of the stator in the axial direction.

10. The at least one oil passage further includes a second oil passage located vertically above the central axis, The motor unit according to claim 6, wherein at least one second opening is provided in the peripheral wall of the housing to communicate between the internal space of the housing and the second oil passage.

11. The second oil passage is configured such that the oil-based refrigerant is supplied from the outside, The motor unit according to claim 10, wherein the at least one second opening includes at least one second outlet opening that supplies the oil-based refrigerant in the second oil passage to the stator.

12. The motor unit according to claim 11, wherein the at least one second outlet opening is directed toward the coil end of the stator.

13. The motor unit according to claim 1, wherein the housing includes a central housing having the peripheral wall, a first cover connected to one end of the central housing in the axial direction, and a second cover connected to the other end of the central housing in the axial direction.

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