Rotating electrical machine, and drive device

Abstract

To provide a rotary electric machine capable of suppressing reduction of static electricity elimination performance of a static eliminator.SOLUTION: A rotary electric machine 10 includes: a static eliminator 80 in electrical contact with a shaft 31 and a housing 20; a housing channel 93a, a nozzle member 70 having a nozzle through hole 70a; and a seal member 120. The shaft includes: a hollow first part 31a; and a second shaft part 110 that includes a lid part 111 and an extension part 112, provided on a part on one axial side of the first shaft part. The extension part axially passes through the nozzle through hole. The static eliminator is in contact with a part positioned on the one axial side of the nozzle through hole in the extension part. The seal member is positioned on the one axial side of the nozzle member, and on the other axial side of the static eliminator. The shaft includes a connection channel 115 communicating with an internal part of the first shaft part and an internal part of the nozzle through hole. The housing channel is open toward an axial gap between the nozzle member and the seal member.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine and a driving device.

Background Art

[0002] A charge dissipation device that dissipates charge from the shaft of a rotating electrical machine is known. For example, Patent Document 1 describes a current shunt ring having a conductive segment that contacts the shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a rotating electrical machine provided with a charge dissipation device as described above, for example, for the purpose of cooling or the like, fluid may be supplied to the rotor, stator, etc. In this case, when the fluid hits the charge dissipation device, the conductivity of the charge dissipation device may decrease, making it difficult to dissipate charge.

[0005] In view of the above circumstances, one object of the present invention is to provide a rotating electrical machine and a driving device that can suppress a decrease in the charge removal performance of the charge removal device.

Means for Solving the Problems

[0006] One aspect of the rotating electrical machine of the present invention includes a rotor having a hollow shaft rotatable about a central axis, a stator facing the rotor with a gap therebetween, a housing that houses the rotor and the stator therein, a bearing that rotatably supports the shaft, a static eliminator fixed to the housing and in electrical contact with the shaft and the housing, a housing flow path portion provided in the housing, a nozzle member having a nozzle through-hole connected to the inside of the shaft, and a seal member positioned between the shaft and the housing in the radial direction. The shaft has a hollow first shaft portion, and a second shaft portion provided with a lid portion on one axial side of the first shaft portion and an extension portion extending axially from the lid portion. The extension portion is axially passed through the nozzle through-hole. The static eliminator is in contact with a portion of the extension portion located axially on one side of the nozzle through-hole. The seal member is located axially on one side of the nozzle member and axially on the other side of the static eliminator. The shaft has a connection flow path portion that connects the inside of the first shaft portion and the inside of the nozzle through-hole. The housing flow path portion opens toward an axial gap between the nozzle member and the seal member inside the housing.

[0007] One aspect of the drive device of the present invention includes the above-described rotating electrical machine and a gear mechanism connected to the rotating electrical machine.

Advantages of the Invention

[0008] According to one aspect of the present invention, it is possible to suppress a decrease in the static elimination performance of the static eliminator in the rotating electrical machine and the drive device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0010] In the following description, based on the positional relationship when the drive device of the embodiment is mounted on a vehicle located on a horizontal road surface, the vertical direction will be defined and described. That is, the relative positional relationship regarding the vertical direction described in the following embodiments only needs to be satisfied at least when the drive device is mounted on a vehicle located on a horizontal road surface.

[0011] In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The side to which the arrow of the Z-axis points (+Z side) is the upper side in the vertical direction, and the side opposite to the side to which the arrow of the Z-axis points (-Z side) is the lower side in the vertical direction. In the following description, the upper side in the vertical direction is simply referred to as the "upper side", and the lower side in the vertical direction is simply referred to as the "lower side". The X-axis direction is a direction orthogonal to the Z-axis direction and is the front-rear direction of the vehicle on which the drive device is mounted. In the following embodiments, the side to which the arrow of the X-axis points (+X side) is the front side of the vehicle, and the side opposite to the side to which the arrow of the X-axis points (-X side) is the rear side of the vehicle. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction and is the left-right direction of the vehicle, that is, the vehicle width direction. In the following embodiments, the side to which the arrow of the Y-axis points (+Y side) is the left side of the vehicle, and the side opposite to the side to which the arrow of the Y-axis points (-Y side) is the right side of the vehicle. The front-rear direction and the left-right direction are horizontal directions orthogonal to the vertical direction.

[0012] Note that the positional relationship in the front-rear direction is not limited to the positional relationship in the following embodiments. The side to which the arrow of the X-axis points (+X side) may be the rear side of the vehicle, and the side opposite to the side to which the arrow of the X-axis points (-X side) may be the front side of the vehicle. In this case, the side to which the arrow of the Y-axis points (+Y side) is the right side of the vehicle, and the side opposite to the side to which the arrow of the Y-axis points (-Y side) is the left side of the vehicle. Also, in this specification, the "parallel direction" includes a substantially parallel direction, and the "orthogonal direction" includes a substantially orthogonal direction.

[0013] The central axis J shown in the figure as appropriate is a virtual axis extending in a direction intersecting the vertical direction. More specifically, the central axis J extends in the Y-axis direction orthogonal to the vertical direction, that is, in the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the central axis J is simply referred to as the "axial direction", the radial direction centered on the central axis J is simply referred to as the "radial direction", and the circumferential direction centered on the central axis J, that is, the axis around the central axis J is simply referred to as the "circumferential direction". In the following embodiments, the right side (-Y side) is referred to as the "one side in the axial direction", and the left side (+Y side) is referred to as the "other side in the axial direction".

[0014] The drive device 100 of the present embodiment shown in FIG. 1 is a drive device mounted on a vehicle and rotates the vehicle axle 64. The vehicle on which the drive device 100 is mounted is a vehicle powered by a motor such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV). As shown in FIG. 1, the drive device 100 includes a rotating electric machine 10 and a gear mechanism 60. The gear mechanism 60 is connected to the rotating electric machine 10 and transmits the rotation of the rotating electric machine 10, that is, the rotation of the rotor 30 described later, to the vehicle axle 64. The gear mechanism 60 of the present embodiment has a gear housing 61, a reduction device 62 connected to the rotating electric machine 10, and a differential device 63 connected to the reduction device 62.

[0015] The gear housing 61 houses a speed reducer 62, a differential device 63, and oil O therein. The oil O is stored in the lower region within the gear housing 61. The oil O circulates within a refrigerant flow path 90 described later. The oil O is used as a refrigerant for cooling the rotating electric machine 10. Also, the oil O is used as a lubricating oil for the speed reducer 62 and the differential device 63. As the oil O, for example, in order to exhibit the functions of a refrigerant and a lubricating oil, it is preferable to use an oil equivalent to an automatic transmission fluid (ATF) with a relatively low viscosity.

[0016] The differential device 63 has a ring gear 63a. Torque output from the rotating electric machine 10 is transmitted to the ring gear 63a via the speed reducer 62. The lower end portion of the ring gear 63a is immersed in the oil O stored within the gear housing 61. As the ring gear 63a rotates, the oil O is scooped up. The scooped-up oil O is supplied, for example, as a lubricating oil to the speed reducer 62 and the differential device 63.

[0017] The rotating electric machine 10 is a part that drives the drive device 100. The rotating electric machine 10 is located, for example, on one axial side (-Y side) of the gear mechanism 60. In the present embodiment, the rotating electric machine 10 is a motor. The rotating electric machine 10 includes a motor housing 20, a rotor 30 having a shaft 31, bearings 34, 35 that rotatably support the rotor 30, a stator 40, a resolver 50, a nozzle member 70, a static eliminator 80, and a seal member 120. The bearings 34, 35 are, for example, ball bearings.

[0018] In this embodiment, the bearings 34 and 35 are ceramic ball bearings. The bearing 34 rotatably supports a portion of the shaft 31 that is located on the other axial side (+Y side) of the stator 40. The bearing 35 rotatably supports a portion of the shaft 31 that is located on one axial side (-Y side) of the stator 40. As shown in FIG. 2, the bearing 35 includes an annular inner ring 35a centered on the central axis J, an annular outer ring 35b centered on the central axis J and located radially outside the inner ring 35a, and a plurality of balls 35c located radially between the inner ring 35a and the outer ring 35b. The configuration of the bearing 34 is the same as that of the bearing 35.

[0019] The motor housing 20 is a housing that houses the rotor 30 and the stator 40 inside. The motor housing 20 is connected to one axial side (-Y side) of the gear housing 61. The motor housing 20 includes a main body portion 21, a partition portion 22, and a motor cover 23. The main body portion 21 and the partition portion 22 are, for example, parts of the same single member. The motor cover 23 is, for example, separate from the main body portion 21 and the partition portion 22.

[0020] The main body portion 21 is cylindrical, surrounding the central axis J and opening on one axial side (-Y side). The partition portion 22 is connected to the end of the main body portion 21 on the other axial side (+Y side). The partition portion 22 axially separates the inside of the motor housing 20 from the inside of the gear housing 61. The partition portion 22 has a partition opening 22a that connects the inside of the motor housing 20 to the inside of the gear housing 61. The bearing 34 is held by the partition portion 22. The motor cover 23 is fixed to the end of the main body portion 21 on one axial side. The motor cover 23 closes the opening on one axial side of the main body portion 21. The bearing 35 is held by the motor cover 23.

[0021] As shown in FIG. 2, the motor cover 23 has a hole 23f that is recessed from the surface on the other axial side (+Y side) of the motor cover 23 toward the one axial side (−Y side). The hole 23f is a hole having a bottom on the one axial side and opening on the other axial side. In the present embodiment, the hole 23f is a circular hole centered on the central axis J. By providing the hole 23f, the motor cover 23 is provided with a bottom wall portion 23a and a peripheral wall portion 23b. That is, the motor housing 20 has a bottom wall portion 23a and a peripheral wall portion 23b.

[0022] The bottom wall portion 23a is the bottom of the hole 23f. A second recess 23g that is recessed toward the one axial side is provided on the surface of the bottom wall portion 23a on the other axial side (+Y side). When viewed in the axial direction, the inner edge of the second recess 23g is circular and centered on the central axis J. The peripheral wall portion 23b protrudes from the radially outer peripheral edge portion of the bottom wall portion 23a toward the other axial side (+Y side). The peripheral wall portion 23b surrounds the shaft 31. The inner peripheral surface of the peripheral wall portion 23b is the inner peripheral surface of the hole 23f. In the present embodiment, the inner peripheral surface of the peripheral wall portion 23b is cylindrical and centered on the central axis J.

[0023] The peripheral wall portion 23b has a first wall portion 23c, a second wall portion 23d, and a third wall portion 23e. The first wall portion 23c is a portion connected to the radially outer peripheral edge portion of the bottom wall portion 23a. The second wall portion 23d is connected to the other axial side (+Y side) of the first wall portion 23c. The inner diameter of the second wall portion 23d is larger than the inner diameter of the first wall portion 23c. The axial dimension of the second wall portion 23d is larger than the axial dimension of the first wall portion 23c. The third wall portion 23e is connected to the other axial side of the second wall portion 23d. The inner diameter of the third wall portion 23e is larger than the inner diameter of the second wall portion 23d. The axial dimension of the third wall portion 23e is larger than the axial dimension of the second wall portion 23d. A bearing 35 is held inside the third wall portion 23e in the radial direction. That is, the bearing 35 is held inside the peripheral wall portion 23b. The outer ring 35b of the bearing 35 is fitted inside the third wall portion 23e in the radial direction.

[0024] In the present embodiment, the inner peripheral surface of the peripheral wall portion 23b has a first stepped portion 24a and a second stepped portion 24b. The first stepped portion 24a is a step provided between the inner peripheral surfaces of the first wall portion 23c and the second wall portion 23d in the axial direction. The first stepped portion 24a has a first stepped surface 24c facing the other axial side (+Y side). The first stepped surface 24c is an annular shape centered on the central axis J. The first stepped surface 24c is a flat surface orthogonal to the axial direction. The second stepped portion 24b is a step provided between the inner peripheral surfaces of the second wall portion 23d and the third wall portion 23e in the axial direction. The second stepped portion 24b has a second stepped surface 24d facing the other axial side. The second stepped surface 24d is an annular shape centered on the central axis J. The second stepped surface 24d is a flat surface orthogonal to the axial direction. The bearing 35 held within the third wall portion 23e is in contact with the second stepped surface 24d. Therefore, the bearing 35 can be suitably positioned axially with respect to the motor housing 20. More specifically, the outer ring 35b of the bearing 35 is in contact with the second stepped surface 24d from the other axial side.

[0025] A resolver holding portion 25 is provided on the other axial side (+Y side) surface of the motor cover 23. In the present embodiment, the resolver holding portion 25 is provided at the peripheral edge of the hole portion 23f on the other axial side surface of the motor cover 23. The resolver holding portion 25 extends in the circumferential direction and surrounds the shaft 31.

[0026] The motor housing 20 has a through hole 23h that axially penetrates the bottom wall portion 23a. The through hole 23h is a circular hole centered on the central axis J. The through hole 23h has a large-diameter hole portion 23i and a small-diameter hole portion 23j. The large-diameter hole portion 23i opens to the bottom surface of the second recess 23g on the other axial side (+Y side) surface of the bottom wall portion 23a. The small-diameter hole portion 23j is connected to the large-diameter hole portion 23i via a step on the one axial side (-Y side). The inner diameter of the small-diameter hole portion 23j is smaller than the inner diameter of the large-diameter hole portion 23i. The small-diameter hole portion 23j opens to the one axial side surface of the bottom wall portion 23a. The axial dimension of the small-diameter hole portion 23j is smaller than the axial dimension of the large-diameter hole portion 23i.

[0027] The motor housing 20 has a housing portion 26 that houses the static eliminator 80 therein. The housing portion 26 is provided on the surface on one axial side (-Y side) of the motor cover 23. The housing portion 26 protrudes axially on one side from the motor cover 23. The housing portion 26 has a cylindrical portion 26a and a lid body 26b. The cylindrical portion 26a protrudes axially on one side from the surface on one axial side of the motor cover 23. As shown in FIG. 3, the cylindrical portion 26a has a substantially cylindrical shape that opens axially on one side. The central axis of the cylindrical portion 26a is parallel to the central axis J of the rotating electric machine 10 and is provided at a position eccentric in the radial direction with respect to the central axis J. The central axis of the cylindrical portion 26a is located, for example, below the central axis J.

[0028] When viewed axially, the cylindrical portion 26a surrounds the through hole 23h. When viewed axially, a part of the bottom wall portion 23a is located inside the cylindrical portion 26a. In the present embodiment, the cylindrical portion 26a and the motor cover 23 are part of the same single member. The cylindrical portion 26a has a plurality of female screw holes 26c. The plurality of female screw holes 26c are provided on the surface on one axial side (-Y side) of the cylindrical portion 26a.

[0029] As shown in FIG. 2, the lid body 26b is fixed to one axial side (-Y side) of the cylindrical portion 26a. Although not shown, the lid body 26b is fixed to the cylindrical portion 26a by bolts respectively tightened into the plurality of female screw holes 26c. The lid body 26b has a plate shape with a plate surface facing the axial direction.

[0030] As shown in FIG. 3, the motor housing 20 has support column portions 26d. The support column portions 26d protrude axially on one side from a portion located inside the cylindrical portion 26a when viewed axially on the surface on one axial side (-Y side) of the motor cover 23. The support column portions 26d have a cylindrical shape. The support column portions 26d are located inside the housing portion 26. A pair of support column portions 26d are provided at intervals in a direction orthogonal to the axial direction. When viewed axially, the through hole 23h is not located between the pair of support column portions 26d. That is, the through hole 23h is arranged offset in a direction orthogonal to the axial direction from between the pair of support column portions 26d.

[0031] As shown in FIG. 1, the rotor 30 has a shaft 31 and a rotor body 32. Although illustration is omitted, the rotor body 32 has a rotor core and a rotor magnet fixed to the rotor core. The torque of the rotor 30 is transmitted to the gear mechanism 60.

[0032] The shaft 31 is rotatable about the central axis J. The shaft 31 is rotatably supported by bearings 34 and 35. The shaft 31 is a hollow shaft. The shaft 31 is cylindrical and extends axially about the central axis J. The shaft 31 is provided with a hole 33 that connects the inside of the shaft 31 and the outside of the shaft 31. The shaft 31 extends across the inside of the motor housing 20 and the inside of the gear housing 61. The end on the other axial side (+Y side) of the shaft 31 protrudes into the inside of the gear housing 61. A speed reduction device 62 is connected to the end on the other axial side of the shaft 31.

[0033] The shaft 31 has a hollow first shaft portion 31a and a second shaft portion 110. In the present embodiment, the first shaft portion 31a and the second shaft portion 110 are separate from each other. The first shaft portion 31a is cylindrical and extends axially about the central axis J. The first shaft portion 31a is open at both axial ends. The first shaft portion 31a extends across the inside of the motor housing 20 and the inside of the gear housing 61. The first shaft portion 31a is rotatably supported by bearings 34 and 35. Note that the first shaft portion 31a may be configured, for example, by axially connecting a motor shaft located in the motor housing 20 and a gear shaft located in the gear housing 61.

[0034] As shown in FIG. 2, the first shaft portion 31a has a large-diameter portion 31b and a small-diameter portion 31c. The small-diameter portion 31c is connected to one axial side (-Y side) of the large-diameter portion 31b. The outer diameter of the small-diameter portion 31c is smaller than the outer diameter of the large-diameter portion 31b. The axial dimension of the small-diameter portion 31c is smaller than the axial dimension of the large-diameter portion 31b. One axial end of the small-diameter portion 31c is the one axial end of the first shaft portion 31a. A stepped portion having a stepped surface facing one axial side is provided between the outer peripheral surface of the large-diameter portion 31b and the outer peripheral surface of the small-diameter portion 31c.

[0035] The portion of the small-diameter portion 31c on one axial side (-Y side) is located radially inside the peripheral wall portion 23b. More specifically, the portion of the small-diameter portion 31c on one axial side is located radially inside the third wall portion 23e. The outer peripheral surface of the small-diameter portion 31c is arranged radially inwardly away from the inner peripheral surface of the peripheral wall portion 23b. The inner ring 35a of the bearing 35 is fixed to the outer peripheral surface of the small-diameter portion 31c. In the present embodiment, the axial position at one axial end of the small-diameter portion 31c is the same as the axial position at one axial end of the bearing 35. A retaining ring 36 is attached to the outer peripheral surface of the small-diameter portion 31c. The retaining ring 36 is arranged to face the other axial side (+Y side) of the inner ring 35a of the bearing 35.

[0036] The second shaft portion 110 is connected to one axial side (-Y side) of the first shaft portion 31a. The second shaft portion 110 is fixed to the opening on one axial side of the first shaft portion 31a. As shown in FIGS. 4 and 5, the second shaft portion 110 is columnar and extends axially about the central axis J. The second shaft portion 110 has a lid portion 111 and an extension portion 112.

[0037] The cover part 111 is cylindrical with the central axis J as the center. As shown in FIG. 2, the cover part 111 is provided at a part on one axial side (-Y side) of the first shaft part 31a. In the present embodiment, the cover part 111 is provided at one axial end of the first shaft part 31a. The cover part 111 is fitted into one axial end of the first shaft part 31a. The cover part 111 is press-fitted into the inside of the first shaft part 31a. Thereby, the second shaft part 110 is fixed to the first shaft part 31a.

[0038] The cover part 111 is located on the radially inner side of the bearing 35. The cover part 111 overlaps the bearing 35 in the radial direction. In other words, the cover part 111 overlaps the bearing 35 when viewed in the radial direction. In the present embodiment, the axial position at one axial end (-Y side) of the cover part 111 is the same as the axial position at one axial end of the first shaft part 31a and the axial position at one axial end of the bearing 35. The end face on one axial side of the cover part 111, the end face on one axial side of the first shaft part 31a, and the end face on one axial side of the inner ring 35a of the bearing 35 are arranged on the same virtual plane orthogonal to the axial direction.

[0039] The cover part 111 has a first recess 113 as a recess that depresses from the surface on one axial side (-Y side) of the cover part 111 to the other axial side (+Y side). As shown in FIG. 5, the inner peripheral edge of the first recess 113 is circular with the central axis J as the center when viewed in the axial direction. As shown in FIG. 2, the axial dimension of the first recess 113 is larger than half of the axial dimension of the cover part 111.

[0040] The lid portion 111 has a lid through-hole 114 that axially penetrates the lid portion 111. In the present embodiment, the lid through-hole 114 axially penetrates the portion of the lid portion 111 where the first recess 113 is provided. One end of the lid through-hole 114 on the -Y side in the axial direction opens into the first recess 113. As shown in FIG. 5, one end of the lid through-hole 114 on the -Y side in the axial direction opens across the bottom surface 113a located on the +Y side in the axial direction and the inner peripheral surface 113b located on the outer side in the radial direction of the inner surface of the first recess 113.

[0041] As shown in FIG. 2, the other end of the lid through-hole 114 on the +Y side in the axial direction opens to the end face on the +Y side in the axial direction of the lid portion 111. The other end of the lid through-hole 114 on the +Y side in the axial direction opens into the first shaft portion 31a. The lid through-hole 114 is a circular hole. The inner diameter of the lid through-hole 114 increases as it goes toward the +Y side in the axial direction. The inner peripheral surface of the lid through-hole 114 is cylindrical, and its inner diameter linearly increases as it goes toward the +Y side in the axial direction. The shape of the inner peripheral surface of the lid through-hole 114 is the same as the outer peripheral surface of a truncated cone whose outer diameter increases as it goes toward the +Y side in the axial direction. The lid through-hole 114 is located on the outer side in the radial direction of the central axis J. As shown in FIG. 4, a plurality of lid through-holes 114 are provided at intervals in the circumferential direction. The plurality of lid through-holes 114 are arranged at equal intervals along the circumferential direction over one full circle. In the present embodiment, six lid through-holes 114 are provided.

[0042] In the present embodiment, each of the lid through-holes 114 constitutes a connection flow path portion 115. That is, the shaft 31 has a connection flow path portion 115. The inner peripheral surface of the connection flow path portion 115 is the inner peripheral surface of the lid through-hole 114. The connection flow path portion 115 is provided in the lid portion 111. In the present embodiment, the connection flow path portions 115 are provided in plurality surrounding the extension portion 112 when viewed in the axial direction. The plurality of connection flow path portions 115 are arranged at equal intervals along the circumferential direction over one full circle. In the present embodiment, six connection flow path portions 115 are provided.

[0043] In this embodiment, since the connection channel portion 115 is provided in the lid portion 111, by providing a lid portion through-hole 114 that penetrates the lid portion 111 in the axial direction, the connection channel portion 115 can be easily formed. Therefore, it is easier to form the connection channel portion 115 compared to the case where the connection channel portion 115 is provided in, for example, the extension portion 112.

[0044] As shown in FIG. 2, the connection channel portion 115 extends in the axial direction. In this embodiment, the connection channel portion 115 connects the inside of the first shaft portion 31a and the inside of the first recess 113. The connection channel portion 115 opens to the inside of the first shaft portion 31a and the inside of the first recess 113. In this embodiment, the connection channel portion 115 is connected to the inside of a nozzle through-hole 70a, which will be described later, via the inside of the first recess 113. Thereby, the connection channel portion 115 is connected to the inside of the first shaft portion 31a and the inside of the nozzle through-hole 70a. As shown in FIG. 5, the connection channel portion 115 opens across a bottom surface 113a located on the other axial side (+Y side) of the inner surface of the first recess 113 and an inner peripheral surface 113b located on the outer diameter side of the inner surface of the first recess 113.

[0045] As shown in FIG. 2, the flow channel cross-sectional area of the connection channel portion 115 increases as it goes toward the other axial side (+Y side). That is, the flow channel cross-sectional area of the connection channel portion 115 increases as it approaches the inside of the first shaft portion 31a. In this embodiment, the flow channel cross-sectional area of the connection channel portion 115 is the area inside the connection channel portion 115 in a cross-section orthogonal to the axial direction. The portion of the inner peripheral surface of the connection channel portion 115 located on the outer diameter side is located on the outer diameter side as it goes toward the other axial side. That is, the portion of the inner peripheral surface of the connection channel portion 115 located on the outer diameter side is located on the outer diameter side as it approaches the inside of the first shaft portion 31a.

[0046] The extension portion 112 extends from the lid portion 111 in one axial direction (-Y side). The extension portion 112 has a cylindrical shape centered on the central axis J. The outer diameter of the extension portion 112 is smaller than the outer diameter of the lid portion 111 and the inner diameter of the first concave portion 113. In the present embodiment, the extension portion 112 extends from the surface of the first concave portion 113 located on the other axial side (+Y side), that is, from the bottom surface 113a, in one axial direction. The end portion of the extension portion 112 on the other axial side is located within the first concave portion 113. The outer peripheral surface of the extension portion 112 is arranged radially inwardly away from the inner peripheral surface 113b of the first concave portion 113. The extension portion 112 protrudes axially on one side of the first concave portion 113.

[0047] The extension portion 112 is axially passed through the through hole 23h. The outer peripheral surface of the extension portion 112 is arranged radially inwardly away from the inner peripheral surface of the through hole 23h. The end portion of the extension portion 112 on one axial side (-Y side) is located inside the housing portion 26. The axial dimension of the extension portion 112 is larger than the axial dimension of the lid portion 111. The axial dimension of the portion of the extension portion 112 located axially on one side of the first concave portion 113 is larger than the axial dimension of the lid portion 111.

[0048] As shown in FIG. 1, the stator 40 faces the rotor 30 with a gap in the radial direction. More specifically, the stator 40 is located radially outside the rotor 30. The stator 40 is fixed inside the motor housing 20. The stator 40 includes a stator core 41 and a coil assembly 42.

[0049] The stator core 41 is annular and surrounds the central axis J of the rotating electrical machine 10. The stator core 41 is located radially outside the rotor 30. The stator core 41 surrounds the rotor 30. The stator core 41 is configured by laminating a plurality of plate members, such as electromagnetic steel sheets, in the axial direction. Although not shown, the stator core 41 has a cylindrical core back extending in the axial direction and a plurality of teeth extending radially inwardly from the core back.

[0050] The coil assembly 42 has a plurality of coils 42c attached to the stator core 41 along the circumferential direction. The plurality of coils 42c are respectively mounted on each tooth of the stator core 41 via an insulator (not shown). The coil assembly 42 has coil ends 42a and 42b that project axially from the stator core 41.

[0051] The resolver 50 can detect the rotation of the rotor 30. The resolver 50 is housed inside the motor housing 20. The resolver 50 has a resolver rotor 51 and a resolver stator 52. The resolver rotor 51 is fixed to the shaft 31. The resolver rotor 51 is annular and surrounds the shaft 31. In the present embodiment, the resolver rotor 51 is annular with the central axis J as the center. As shown in FIG. 2, in the present embodiment, the resolver rotor 51 surrounds the end portion on the other axial side (+Y side) of the small-diameter portion 31c. The resolver rotor 51 is plate-shaped with the plate surface facing the axial direction. The axial other surface of the resolver rotor 51 is in contact with the step surface of the step provided axially between the large-diameter portion 31b and the small-diameter portion 31c. The resolver rotor 51 projects radially outward from the outer peripheral surface of the large-diameter portion 31b. The resolver rotor 51 is arranged at an interval on the other axial side of the bearing 35.

[0052] The resolver stator 52 is located radially outside the resolver rotor 51. The resolver stator 52 is annular and surrounds the resolver rotor 51. The resolver stator 52 is held by the resolver holder 25. Although not shown, the resolver stator 52 has coils. When the resolver rotor 51 rotates together with the shaft 31, an induced voltage corresponding to the circumferential position of the resolver rotor 51 is generated in the coils of the resolver stator 52. The resolver 50 can detect the rotation of the resolver rotor 51 and the shaft 31 based on the change in the induced voltage generated in the coils of the resolver stator 52. Thereby, the resolver 50 can detect the rotation of the rotor 30.

[0053] The static eliminator 80 is housed inside the housing portion 26. As shown in FIG. 3, the static eliminator 80 is located radially outside the portion of the extending portion 112 that is positioned within the housing portion 26. The static eliminator 80 is, for example, located below the extending portion 112. The static eliminator 80 includes a holder portion 81, a brush portion 82, and a fixed portion 83. In the present embodiment, the holder portion 81 has a rectangular parallelepiped shape that is long in the radial direction. The holder portion 81 holds the brush portion 82.

[0054] The brush portion 82 protrudes radially inward from the holder portion 81. The brush portion 82 has a substantially rectangular parallelepiped shape. In the present embodiment, the brush portion 82 is a carbon brush. The brush portion 82 is located radially outside the extending portion 112. The radially inner end portion of the brush portion 82 is in electrical contact with the outer peripheral surface of the extending portion 112. Thereby, the static eliminator 80 is in electrical contact with the shaft 31. In the present embodiment, the static eliminator 80 is in contact with a portion of the extending portion 112 that is located on one axial side (-Y side) of a nozzle through-hole 70a, which will be described later. The shaft 31 rotates while the outer peripheral surface of the extending portion 112 is rubbed against the radially inner end portion of the brush portion 82. Note that in this specification, "a certain object is in electrical contact with another object" means that an electric current can flow between the certain object and the other object.

[0055] The fixed portion 83 protrudes from the holder portion 81 in a direction orthogonal to both the axial direction and the direction in which the brush portion 82 protrudes from the holder portion 81. The fixed portion 83 has a plate shape with a plate surface facing the axial direction. The fixed portion 83 is made of metal. Although not shown, the fixed portion 83 is electrically connected to the brush portion 82, for example, inside the holder portion 81. A pair of fixed portions 83 are provided sandwiching the holder portion 81 in a direction orthogonal to both the axial direction and the direction in which the brush portion 82 protrudes from the holder portion 81. The pair of fixed portions 83 are respectively fixed to a pair of support pillar portions 26d with bolts. Thereby, the static eliminator 80 is fixed to the motor housing 20. The fixed portion 83 is in electrical contact with the motor housing 20 via the support pillar portion 26d. Thereby, the static eliminator 80 is in electrical contact with the motor housing 20.

[0056] As described above, since the fixed part 83 is electrically connected to the brush part 82, the brush part 82 is electrically in contact with the shaft 31, and the fixed part 83 is electrically in contact with the motor housing 20, the shaft 31 and the motor housing 20 are electrically connected via the static eliminator 80. Therefore, the current generated in the shaft 31 can flow from the support column part 26d to the motor housing 20 through the brush part 82 and the fixed part 83 in this order. Thereby, it is possible to suppress the current from flowing from the shaft 31 to the bearings 34 and 35 that rotatably support the shaft 31. Therefore, it is possible to suppress the occurrence of electrolytic corrosion in the bearings 34 and 35.

[0057] The nozzle member 70 is a member for supplying oil O as a fluid inside the shaft 31. As shown in FIG. 2, the nozzle member 70 is made, for example, by subjecting a metal plate member to machining such as press working. The nozzle member 70 is disposed inside the peripheral wall portion 23b. The nozzle member 70 is disposed apart from the other axial side (+Y side) of the bottom wall portion 23a. The nozzle member 70 has a supply cylinder portion 71, a flange portion 72, and a protruding cylinder portion 73.

[0058] The supply cylinder portion 71 extends in the axial direction. In the present embodiment, the supply cylinder portion 71 has a cylindrical shape centered on the central axis J. The supply cylinder portion 71 is open at both axial ends. An extension portion 112 is passed axially inside the supply cylinder portion 71 in the radial direction. The end portion on the other axial side (+Y side) of the supply cylinder portion 71 is located in the first recess 113. The outer peripheral surface of the supply cylinder portion 71 is disposed radially inwardly away from the inner peripheral surface 113b of the first recess 113. The supply cylinder portion 71 has a discharge cylinder portion 71a and a guide cylinder portion 71b.

[0059] The discharge cylinder part 71a is cylindrical with the central axis J as the center and opens to the other axial side (+Y side). The end part on the other axial side of the discharge cylinder part 71a is the end part on the other axial side of the supply cylinder part 71. The inner diameter and outer diameter of the discharge cylinder part 71a are the same throughout the entire axial direction. The discharge cylinder part 71a opens inside the first recess 113. The part on the other axial side of the discharge cylinder part 71a is located inside the first recess 113. The end part on the other axial side of the discharge cylinder part 71a is arranged to be separated from the bottom surface 113a of the first recess 113 toward the one axial side (-Y side). The end part on the other axial side of the discharge cylinder part 71a faces, with a gap therebetween in the axial direction, a part on the radially inner side of the part of the bottom surface 113a of the first recess 113 where the connecting flow path part 115 opens. The part on the one axial side (-Y side) of the discharge cylinder part 71a is located on the one axial side of the inside of the first recess 113.

[0060] The guide cylinder part 71b is connected to the one axial side (-Y side) of the discharge cylinder part 71a. The guide cylinder part 71b is cylindrical with the central axis J as the center and opens to the one axial side. The end part on the one axial side of the guide cylinder part 71b is the end part on the one axial side of the supply cylinder part 71. The inner diameter and outer diameter of the guide cylinder part 71b increase as going toward the one axial side. The guide cylinder part 71b is a frustum-shaped cylinder with the inner diameter and outer diameter increasing as going toward the one axial side. The outer diameter at the end part on the other axial side (+Y side) of the guide cylinder part 71b is the same as the outer diameter at the end part on the one axial side of the discharge cylinder part 71a and is smaller than the inner diameter of the first recess 113. The inner diameter at the end part on the other axial side of the guide cylinder part 71b is the same as the inner diameter at the end part on the one axial side of the discharge cylinder part 71a. The outer diameter at the end part on the one axial side of the guide cylinder part 71b is larger than the inner diameter of the first recess 113.

[0061] The guide cylinder portion 71b is disposed away from one axial side (-Y side) of the lid portion 111. The guide cylinder portion 71b faces the lid portion 111 axially with a gap therebetween. The guide cylinder portion 71b is located radially inside the second wall portion 23d. The opening on one axial side of the guide cylinder portion 71b faces the second recess 23g axially with a gap therebetween. The axial dimension of the guide cylinder portion 71b is larger than the axial dimension of the discharge cylinder portion 71a.

[0062] The supply cylinder portion 71 constitutes the nozzle through hole 70a. That is, the nozzle member 70 has the nozzle through hole 70a. The inside of the nozzle through hole 70a is the inside of the supply cylinder portion 71. The nozzle through hole 70a penetrates the nozzle member 70 axially. The nozzle through hole 70a is a circular hole centered on the central axis J. The inner diameter of the portion of the nozzle through hole 70a constituted by the discharge cylinder portion 71a is the same throughout the axial direction. The inner diameter of the portion of the nozzle through hole 70a constituted by the guide cylinder portion 71b increases toward one axial side (-Y side).

[0063] The extension portion 112 is passed through the nozzle through hole 70a axially. The inner peripheral surface of the nozzle through hole 70a is disposed radially outward from the outer peripheral surface of the extension portion 112. A gap is provided throughout the entire circumference in the circumferential direction between the inner peripheral surface of the nozzle through hole 70a and the outer peripheral surface of the extension portion 112. The oil O flowing through the nozzle through hole 70a flows through the radial gap between the inner peripheral surface of the nozzle through hole 70a and the outer peripheral surface of the extension portion 112. The nozzle through hole 70a opens into the first recess 113. In the present embodiment, the nozzle through hole 70a is connected to the inside of the shaft 31 through the inside of the first recess 113 and the connection flow path portion 115.

[0064] The opening on the other axial side (+Y side) of the nozzle through-hole 70a is arranged away from the bottom surface 113a of the first concave portion 113 on the one axial side (-Y side). The opening on the other axial side of the nozzle through-hole 70a faces, with a gap therebetween in the axial direction, a portion on the radially inner side of the portion of the bottom surface 113a of the first concave portion 113 where the connection flow path portion 115 opens. The inner edge at the opening on the other axial side of the nozzle through-hole 70a is located radially inward of the opening of the connection flow path portion 115 that opens to the bottom surface 113a.

[0065] The flange portion 72 extends radially outward from the supply cylinder portion 71. In the present embodiment, the flange portion 72 protrudes radially outward from the end portion on the one axial side (-Y side) of the supply cylinder portion 71. The flange portion 72 is annular and surrounds the central axis J. In the present embodiment, the flange portion 72 is in the shape of an annular ring centered on the central axis J. The flange portion 72 is plate-shaped with the plate surface facing the axial direction. The radially outer edge portion of the flange portion 72 is in contact with the first stepped surface 24c. The portion of the flange portion 72 excluding the radially outer edge portion faces the bottom wall portion 23a with a gap therebetween in the axial direction. The flange portion 72 is arranged to face the one axial side of the bearing 35. Thus, in the present embodiment, a part of the nozzle member 70 faces the bearing 35 in the axial direction.

[0066] The protruding cylinder portion 73 protrudes from the radially outer edge portion of the flange portion 72 toward the other axial side (+Y side). The protruding cylinder portion 73 is cylindrical with the central axis J as the center. The protruding cylinder portion 73 is fitted in the radially inner side of the second wall portion 23d with a clearance fit. Thereby, the nozzle member 70 is fitted inside the peripheral wall portion 23b. The end portion on the other axial side of the protruding cylinder portion 73 faces the bearing 35 in the axial direction. The end portion on the other axial side of the protruding cylinder portion 73 is in contact with the outer ring 35b of the bearing 35. The end portion on the other axial side of the protruding cylinder portion 73 is located on the one axial side (-Y side) with respect to the end portion on the other axial side of the supply cylinder portion 71 in the axial direction. The inner peripheral surface of the protruding cylinder portion 73 is located radially outward of the inner peripheral surface of the outer ring 35b of the bearing 35. At least a part of the outer peripheral surface of the protruding cylinder portion 73 is in contact with, for example, the inner peripheral surface of the second wall portion 23d.

[0067] In this embodiment, since the flange portion 72 contacts the first stepped surface 24c and the protruding cylindrical portion 73 contacts the bearing 35, the nozzle member 70 is positioned in the axial direction. In this embodiment, after arranging the nozzle member 70 inside the peripheral wall portion 23b and then arranging the bearing 35, the bearing 35 can fix the nozzle member 70 in the axial direction. Note that the flange portion 72 and the first stepped surface 24c may face each other with a gap therebetween without contacting each other, or the protruding cylindrical portion 73 and the bearing 35 may face each other with a gap therebetween without contacting each other.

[0068] The nozzle member 70 has a through hole 74 that axially penetrates a portion of the nozzle member 70 that axially faces the bearing 35. In this embodiment, the portion of the nozzle member 70 that axially faces the bearing 35 includes the flange portion 72 and the protruding cylindrical portion 73. In this embodiment, the through hole 74 is provided in the flange portion 72. As shown in FIGS. 4 and 5, the through hole 74 is a circular hole that axially penetrates the flange portion 72. A plurality of through holes 74 are provided at intervals in the circumferential direction. In this embodiment, two through holes 74 are provided with the central axis J interposed therebetween in the radial direction. As shown in FIG. 2, the through hole 74 axially faces the inner ring 35a of the bearing 35 with a gap therebetween. The through hole 74 is a supply hole that supplies oil O as a fluid to the bearing 35. The inner diameter of the through hole 74 is smaller than the inner diameter of the nozzle through hole 70a.

[0069] The seal member 120 is annular and surrounds the shaft 31. In this embodiment, the seal member 120 is annular with the central axis J as the center. The seal member 120 is located in the radial space between the shaft 31 and the motor housing 20. In this embodiment, the seal member 120 is fixed in the large-diameter hole portion 23i of the through hole 23h provided in the bottom wall portion 23a. The seal member 120 is located on one axial side (-Y side) of the nozzle member 70 and on the other axial side (+Y side) of the static eliminator 80.

[0070] The radially outer edge portion of the seal member 120 is in contact with the inner peripheral surface of the large-diameter hole portion 23i. The radially inner edge portion of the seal member 120 is in contact with the outer peripheral surface of the extension portion 112. Thereby, the seal member 120 seals the radial space between the inner peripheral surface of the large-diameter hole portion 23i and the outer peripheral surface of the extension portion 112. In the present embodiment, the radially inner edge portion of the seal member 120 is elastically deformable in the radial direction and is pressed against the outer peripheral surface of the extension portion 112 by an elastic force. In the present embodiment, the seal member 120 is an oil seal.

[0071] As shown in FIG. 1, in the present embodiment, the drive device 100 is provided with a refrigerant flow path 90 through which oil O as a refrigerant circulates. The refrigerant flow path 90 is provided across the inside of the motor housing 20 and the inside of the gear housing 61. The refrigerant flow path 90 is a path through which the oil O stored in the gear housing 61 is supplied to the rotating electric machine 10 and then returns to the gear housing 61 again. The refrigerant flow path 90 is provided with a pump 96, a cooler 97, and a refrigerant supply portion 95. In the following description, the upstream side in the flow direction of the oil O in the refrigerant flow path 90 is simply referred to as the "upstream side", and the downstream side in the flow direction of the oil O in the refrigerant flow path 90 is simply referred to as the "downstream side". The refrigerant flow path 90 includes a gear-side flow path portion 91, an intermediate flow path portion 92, and a rotating electric machine-side flow path portion 93.

[0072] The gear-side flow path portion 91 includes a first portion 91a and a second portion 91b. The first portion 91a and the second portion 91b are provided, for example, on the wall portion of the gear housing 61. The first portion 91a connects the portion of the inside of the gear housing 61 where the oil O is stored and the pump 96. The second portion 91b connects the pump 96 and the cooler 97.

[0073] The intermediate flow path portion 92 is provided across the wall portion of the gear housing 61 and the wall portion of the motor housing 20. The intermediate flow path portion 92 connects the gear-side flow path portion 91 and the rotating electric machine-side flow path portion 93. More specifically, the intermediate flow path portion 92 connects the cooler 97 and a third flow path portion 93c described later.

[0074] The rotating electrical machine side flow path portion 93 is provided in the rotating electrical machine 10. The rotating electrical machine side flow path portion 93 includes a first flow path portion 93a, a second flow path portion 93b, and a third flow path portion 93c. That is, the rotating electrical machine 10 includes the first flow path portion 93a, the second flow path portion 93b, and the third flow path portion 93c. The first flow path portion 93a and the third flow path portion 93c are provided on the wall portion of the motor housing 20. The second flow path portion 93b includes a fourth flow path portion 93d provided on the wall portion of the motor housing 20 and a refrigerant supply portion 95. In the present embodiment, the first flow path portion 93a, the third flow path portion 93c, and the fourth flow path portion 93d are provided on the motor cover 23. The first flow path portion 93a and the second flow path portion 93b are connected to the third flow path portion 93c. In the present embodiment, the first flow path portion 93a and the second flow path portion 93b branch off from the third flow path portion 93c.

[0075] The first flow path portion 93a is a flow path portion that supplies oil O as a fluid to the inside of the peripheral wall portion 23b. The upstream end of the first flow path portion 93a is connected to the downstream end of the third flow path portion 93c. The downstream end of the first flow path portion 93a opens to the inside of the peripheral wall portion 23b. As shown in FIG. 2, the downstream end of the first flow path portion 93a opens to the surface on the other axial direction side (+Y side) of the bottom wall portion 23a. In the present embodiment, the downstream end of the first flow path portion 93a opens to the inside of the second recess 23g. The downstream end of the first flow path portion 93a is a supply port 93e that supplies oil O into the peripheral wall portion 23b.

[0076] The first flow path portion 93a opens toward the axial gap 27 between the nozzle member 70 and the seal member 120 inside the motor housing 20. In the present embodiment, the axial gap 27 is a portion that is located on the one axial direction side (-Y side) of the nozzle member 70 and on the other axial direction side (+Y side) of the seal member 120 in the internal space of the peripheral wall portion 23b. The axial gap 27 includes the space radially inside the first wall portion 23c and the internal space of the second recess 23g. Note that, in the present embodiment, the first flow path portion 93a corresponds to the "housing flow path portion" provided in the motor housing 20.

[0077] As shown in FIG. 1, the second flow path portion 93b is a flow path portion that supplies oil O as a fluid to the stator 40. The upstream end of the fourth flow path portion 93d in the second flow path portion 93b is connected to the downstream end of the third flow path portion 93c. The downstream end of the fourth flow path portion 93d is connected to the upstream end of the refrigerant supply portion 95.

[0078] In the present embodiment, the refrigerant supply portion 95 is tubular and extends in the axial direction. In other words, in the present embodiment, the refrigerant supply portion 95 is a pipe that extends in the axial direction. Both axial ends of the refrigerant supply portion 95 are supported by the motor housing 20. The axial end on the other side (+Y side) of the refrigerant supply portion 95 is supported by, for example, the partition wall portion 22. The axial end on one side (-Y side) of the refrigerant supply portion 95 is supported by, for example, the motor cover 23.

[0079] The refrigerant supply portion 95 is located on the radially outer side of the stator 40. In the present embodiment, the refrigerant supply portion 95 is located above the stator 40. In the present embodiment, the direction in which the oil O flows in the refrigerant supply portion 95 is from one axial side to the other axial side. That is, in the flow direction of the oil O in the refrigerant supply portion 95, one axial side is the upstream side and the other axial side is the downstream side. The refrigerant supply portion 95 has a supply port 95a that supplies oil O as a refrigerant to the stator 40. In the present embodiment, the supply port 95a is an injection port that injects a part of the oil O flowing into the refrigerant supply portion 95 to the outside of the refrigerant supply portion 95. A plurality of supply ports 95a are provided.

[0080] When the pump 96 is driven, the oil O stored in the gear housing 61 is sucked up through the first portion 91a and flows into the cooler 97 through the second portion 91b. The oil O that has flowed into the cooler 97 is cooled in the cooler 97 and then flows from the intermediate flow path portion 92 into the rotating electrical machine side flow path portion 93 through the third flow path portion 93c. The oil O that has flowed into the third flow path portion 93c branches into a first flow path portion 93a and a second flow path portion 93b. As shown in FIG. 2, the oil O that has flowed into the first flow path portion 93a flows into the inside of the peripheral wall portion 23b. In the present embodiment, the oil O from the first flow path portion 93a flows into the second recess 23g provided in the bottom wall portion 23a. The oil O from the first flow path portion 93a flows into the axial clearance 27.

[0081] A part of the oil O that has flowed into the axial clearance 27 flows into the inside of the first recess 113 through the nozzle through hole 70a. More specifically, a part of the oil O that has flowed into the axial clearance 27 flows into the inside of the first recess 113 through the guide cylinder portion 71b and the discharge cylinder portion 71a in this order. Another part of the oil O that has flowed from the first flow path portion 93a into the axial clearance 27 flows through the through portion 74 to the other axial side (+Y side) of the flange portion 72. The oil O that has flowed through the through portion 74 to the other axial side of the flange portion 72 flows, for example, along the surface on the other axial side of the flange portion 72 and the inner peripheral surface of the protruding cylinder portion 73 and is supplied to the bearing 35. The amount of the oil O passing through the through portion 74 is less than the amount of the oil O passing through the nozzle through hole 70a.

[0082] A part of the oil O that has flowed into the inside of the first recess 113 flows into the inside of the first shaft portion 31a through the plurality of connection flow path portions 115. A part of the oil O that has flowed into the inside of the first shaft portion 31a flows axially to the other side (+Y side) inside the first shaft portion 31a. As shown in FIG. 1, the oil O that has flowed from the nozzle member 70 into the shaft 31 and flows axially to the other side inside the first shaft portion 31a passes through the hole portion 33, passes through the inside of the rotor main body 32, and scatters to the stator 40.

[0083] As shown in FIG. 2, another part of the oil O that has flowed into the inside of the first recess 113 is discharged from the inside of the first recess 113 to one axial side (-Y side) through a portion of the inside of the first recess 113 that is located radially outside the discharge cylinder portion 71a. The oil O discharged from the inside of the first recess 113 to one axial side flows, for example, along the outer peripheral surface of the supply cylinder portion 71, the surface on the other axial side (+Y side) of the flange portion 72, and the inner peripheral surface of the protruding cylinder portion 73, and is supplied to the bearing 35. The amount of the oil O discharged from the inside of the first recess 113 to one axial side is less than the amount of the oil O discharged into the first shaft portion 31a through the connection flow path portion 115.

[0084] As shown in FIG. 1, the oil O that has flowed into the second flow path portion 93b flows through the fourth flow path portion 93d into the inside of the refrigerant supply portion 95. The oil O that has flowed into the refrigerant supply portion 95 is jetted from the supply port 95a and supplied to the stator 40. In this way, by providing the first flow path portion 93a and the second flow path portion 93b that branch from the third flow path portion 93c, the oil O sent from inside the gear housing 61 can be suitably and easily supplied into the shaft 31 through the inside of the peripheral wall portion 23b and can be supplied from the refrigerant supply portion 95 to the stator 40.

[0085] In the present embodiment, a part of the oil O lifted by the ring gear 63a enters the reservoir 98 provided inside the gear housing 61. The oil O that has entered the reservoir 98 flows into the shaft 31 from the end portion on the other axial side (+Y side). The oil O that has flowed into the shaft 31 from the reservoir 98 passes through the hole portion 33 and the inside of the rotor body 32 and scatters to the stator 40.

[0086] The oil O supplied from the supply port 95a to the stator 40 and the oil O supplied from inside the shaft 31 to the stator 40 take heat from the stator 40. The oil O that has cooled the stator 40 drops downward and accumulates in the lower region within the motor housing 20. The oil O that has accumulated in the lower region within the motor housing 20 returns into the gear housing 61 through the partition opening 22a provided in the partition portion 22. In this way, the refrigerant flow path 90 supplies the oil O stored in the gear housing 61 to the rotor 30 and the stator 40.

[0087] According to the present embodiment, the static eliminator 80 is in contact with a portion of the extending portion 112 that is located on one axial side (-Y side) of the nozzle through-hole 70a. The seal member 120 is located on one axial side of the nozzle member 70 and on the other axial side (+Y side) of the static eliminator 80. Therefore, the seal member 120 can seal the radial gap between the portion of the extending portion 112 that is located axially between the nozzle member 70 and the static eliminator 80 and the motor housing 20. Thereby, the seal member 120 can suppress the oil O flowing through the nozzle member 70 from flowing to the static eliminator 80. Therefore, it is possible to suppress a decrease in the conductivity of the static eliminator 80 due to the oil O. As a result, it is possible to suppress the current generated in the shaft 31 from flowing easily to the motor housing 20 through the static eliminator 80. That is, it is possible to suppress a decrease in the static elimination performance of the static eliminator 80. Therefore, for example, it is not necessary to make the static eliminator 80 an anti-oil static eliminator, and it is easy to make the static eliminator 80 a relatively inexpensive static eliminator.

[0088] In the present embodiment, the static eliminator 80 has a carbon brush as a brush portion 82 that is in electrical contact with the extending portion 112. Such a static eliminator 80 having a carbon brush is less expensive than, for example, a static eliminator having an annular brush portion composed of a plurality of conductive fibers. Therefore, the cost of the static eliminator 80 can be reduced, and the manufacturing cost of the rotating electrical machine 10 can be reduced.

[0089] Also, when a carbon brush is brought into contact with a portion of the shaft 31 having a relatively large outer diameter, the circumferential dimension of the portion of the outer peripheral surface of the shaft 31 where the carbon brush rubs becomes relatively large. Therefore, the carbon brush is likely to wear. In contrast, in the present embodiment, the brush portion 82 is in contact with the extending portion 112. Since it is not necessary to flow the oil O inside the extending portion 112 unlike the first shaft portion 31a, the outer diameter of the extending portion 112 can be made smaller than the outer diameter of the first shaft portion 31a. As a result, the brush portion 82 can be brought into contact with a portion of the shaft 31 having a relatively small outer diameter. Therefore, even when the brush portion 82 is a relatively inexpensive carbon brush, it is possible to suppress the wear of the brush portion 82.

[0090] Further, according to the present embodiment, the shaft 31 has a connection flow path portion 115 that connects the inside of the first shaft portion 31a and the inside of the nozzle through hole 70a. The first flow path portion 93a, which is a housing flow path portion provided in the motor housing 20, opens toward the axial gap 27 between the nozzle member 70 and the seal member 120 inside the motor housing 20. Therefore, for example, as in the present embodiment, the oil O supplied from the first flow path portion 93a to the axial gap 27 can be supplied to the inside of the first shaft portion 31a through the nozzle through hole 70a and the connection flow path portion 115. Thereby, the oil O can be suitably supplied to the inside of the shaft 31.

[0091] The static eliminator 80 may be a static eliminator 80 having excellent oil resistance or a static eliminator having relatively poor oil resistance. "The static eliminator 80 has excellent oil resistance" means that changes caused by the static eliminator 80 coming into contact with the oil O are unlikely to occur in the static eliminator 80. Also, the oil resistance can be considered to be evaluated by an immersion test in the oil O. In this case, the oil resistance is evaluated based on the weight change and strength change after immersion for a predetermined time. The evaluation of the weight change includes, for example, the viewpoints of corrosion and swelling.

[0092] Further, according to the present embodiment, the nozzle member 70 has a through portion 74 that axially penetrates a portion of the nozzle member 70 that axially faces the bearing 35. Therefore, a part of the oil O in the axial clearance 27 can be supplied to the bearing 35 as lubricating oil through the through portion 74. Thereby, the oil O can be suitably supplied to the bearing 35.

[0093] Here, in the present embodiment, the bearing 35 is a ceramic ball bearing. Many ceramic ball bearings have a structure in which grease cannot be enclosed inside. Therefore, when the bearing 35 is a ceramic ball bearing as in the present embodiment, it is particularly important that the oil O can be supplied as lubricating oil from the outside of the bearing 35. Further, when the bearing 35 is a ceramic ball bearing, the current generated in the shaft 31 can be suppressed from flowing into the bearing 35. Therefore, a circulating current flowing through the shaft 31, the bearing 35, and the motor housing 20 can be suppressed from occurring.

[0094] Further, according to the present embodiment, the flow path cross-sectional area of the connection flow path portion 115 increases as it approaches the inside of the first shaft portion 31a. Therefore, the oil O flowing into the connection flow path portion 115 from the nozzle member 70 can be easily discharged into the first shaft portion 31a. Thereby, the oil O can be more easily supplied to the inside of the shaft 31. In the present embodiment, the connection flow path portion 115 is located on the radially outer side of the central axis J, and the inner peripheral surface of the connection flow path portion 115 is cylindrical with an inner diameter that increases as it approaches the inside of the first shaft portion 31a. Therefore, the portion of the inner peripheral surface of the connection flow path portion 115 located on the radially outer side is located on the radially outer side as it approaches the inside of the first shaft portion 31a in the axial direction. Thus, when the oil O is pressed against the portion of the inner peripheral surface of the connection flow path portion 115 located on the radially outer side by the centrifugal force generated by the rotation of the shaft 31, the pressed oil O easily flows along the inner peripheral surface of the connection flow path portion 115 toward the inside of the first shaft portion 31a. Therefore, the oil O flowing into the connection flow path portion 115 can be more suitably discharged into the first shaft portion 31a.

[0095] Further, according to the present embodiment, the lid portion 111 has a first recess 113 that is recessed from the surface on one axial side (-Y side) of the lid portion 111 toward the other axial side (+Y side). The end portion on the other axial side of the supply cylinder portion 71 that constitutes the nozzle through-hole 70a is located within the first recess 113. The connection flow path portion 115 opens into the interior of the first recess 113 and is connected to the interior of the nozzle through-hole 70a through the interior of the first recess 113. Therefore, the oil O can be supplied from the supply cylinder portion 71 into the first recess 113, and the oil O can flow from the first recess 113 into the connection flow path portion 115. Thereby, the oil O flowing in the nozzle through-hole 70a can be suitably made to flow into the connection flow path portion 115. Accordingly, the oil O can be more suitably supplied into the interior of the shaft 31.

[0096] Further, according to the present embodiment, the connection flow path portion 115 opens across the bottom surface 113a located on the other axial side (+Y side) of the inner surface of the first recess 113 and the inner peripheral surface 113b located on the outer side in the radial direction of the inner surface of the first recess 113. Therefore, for example, compared with the case where the connection flow path portion 115 opens only to the bottom surface 113a, the oil O flowing into the first recess 113 from the nozzle through-hole 70a can be more easily made to flow into the connection flow path portion 115. In particular, since the oil O flowing into the first recess 113 receives a force in the radially outward direction by centrifugal force, the oil O flowing in the radially outward direction by centrifugal force in the first recess 113 easily flows into the connection flow path portion 115 from the portion that opens to the inner peripheral surface 113b of the connection flow path portion 115.

[0097] Further, according to the present embodiment, the extension portion 112 extends from the bottom surface 113a located on the other axial side (+Y side) of the inner surface of the first recess 113 toward the one axial side (-Y side). A plurality of connection flow path portions 115 are provided so as to surround the extension portion 112 when viewed in the axial direction. Therefore, while providing the first recess 113 and disposing the axial end portion of the supply cylinder portion 71 within the first recess 113, the extension portion 112 can be easily passed through the nozzle through-hole 70a. Also, the oil O can be more suitably supplied into the first shaft portion 31a by the plurality of connection flow path portions 115.

[0098] Also, according to the present embodiment, the nozzle member 70 has a flange portion 72 that extends radially outward from the supply cylinder portion 71 and is disposed to face one axial side (-Y side) of the bearing 35, and a protruding cylinder portion 73 that protrudes from the radially outer edge portion of the flange portion 72 toward the other axial side (+Y side). Therefore, the flange portion 72 can suppress the oil O flowing into the axial gap 27 from flowing past the bearing 35. Thereby, the oil O flowing into the axial gap 27 can be easily supplied into the shaft 31 through the supply cylinder portion 71. Further, as described above, the oil O flowing out from the first recess 113 toward one axial side can be preferably guided to the bearing 35 along the supply cylinder portion 71, the flange portion 72, and the protruding cylinder portion 73.

[0099] Also, according to the present embodiment, the lid portion 111 overlaps the bearing 35 in the radial direction. Therefore, the connection flow path portion 115 provided in the lid portion 111 can be disposed at a position close to the bearing 35. Thereby, the oil O that has leaked out without flowing into the connection flow path portion 115 among the oil O supplied from the nozzle member 70 can be easily supplied to the bearing 35. Specifically, in the present embodiment, the oil O leaking out through the opening on one axial side (-Y side) of the first recess 113 can be easily supplied to the bearing 35.

[0100] Also, according to the present embodiment, the axial position at the end on one axial side (-Y side) of the lid portion 111 is the same as the axial position at the end on one axial side of the bearing 35. Therefore, the connection flow path portion 115 provided in the lid portion 111 can be disposed at a position closer to the bearing 35. Thereby, the oil O that has leaked out without flowing into the connection flow path portion 115 among the oil O supplied from the nozzle member 70 can be more easily supplied to the bearing 35.

[0101] The present invention is not limited to the above-described embodiments, and other configurations and other methods can also be adopted within the scope of the technical idea of the present invention. The first shaft portion and the second shaft portion do not have to be separate from each other. The first shaft portion and the second shaft portion may be part of the same single member. When the first shaft portion is configured by axially connecting a motor shaft located within the motor housing and a gear shaft located within the gear housing, the motor shaft and the second shaft portion may be part of the same single member. The lid portion of the second shaft portion does not have to have a recess into which the supply cylinder portion of the nozzle member is inserted. The relative positional relationship between the lid portion and the bearing is not particularly limited.

[0102] The connection flow path portion provided in the shaft may have any configuration as long as it connects the inside of the first shaft portion and the inside of the nozzle through-hole. The connection flow path portion may be provided across the lid portion and the extension portion in the second shaft portion, may be provided across the first shaft portion and the second shaft portion, or may be provided only in the first shaft portion. The connection flow path portion may have any shape. The flow path cross-sectional area of the connection flow path portion may be uniform throughout. The connection flow path portion may be directly connected to the inside of the first shaft portion and the inside of the nozzle through-hole. The number of connection flow path portions is not particularly limited as long as it is one or more.

[0103] The static eliminator may be of any type as long as it is in electrical contact with the shaft and the housing of the rotating electric machine and can discharge the current flowing through the shaft to the housing. The static eliminator may be a static eliminator having an annular brush portion composed of a plurality of conductive fibers.

[0104] The nozzle member may have any shape as long as it has a nozzle through-hole. The through-hole that axially penetrates the portion of the nozzle member that axially faces the bearing may have any shape or may be a notch instead of a hole. The number of through-holes is not particularly limited. The through-hole does not have to be provided.

[0105] The housing flow path portion provided in the housing of the rotating electrical machine may be any flow path portion as long as it opens toward the axial gap between the nozzle member and the seal member inside the housing. The housing flow path portion does not have to be a flow path portion that supplies fluid into the axial gap between the nozzle member and the seal member inside the housing. For example, the fluid may flow from inside the shaft, through the connecting flow path portion and the nozzle through hole, into the axial gap, and from the axial gap into the housing flow path portion.

[0106] The fluid flowing through the housing flow path portion and the fluid flowing through the nozzle member may be any type of fluid. The fluid may be an insulating liquid or water. When the fluid is water, the surface of the stator may be subjected to an insulating treatment. The bearing to which the fluid is supplied via the nozzle member may be any type of bearing.

[0107] The seal member located between the shaft and the housing in the radial direction may have any configuration as long as it is located on one axial side of the nozzle member and on the other axial side of the static eliminator. The seal member may be any type of seal member as long as it can seal between the shaft and the housing in the radial direction.

[0108] The rotating electrical machine to which the present invention is applied is not limited to a motor and may be a generator. The use of the rotating electrical machine is not particularly limited. The rotating electrical machine may be mounted on a vehicle for uses other than rotating an axle, or may be mounted on equipment other than a vehicle. The attitude when the rotating electrical machine is used is not particularly limited. The central axis of the rotating electrical machine may extend in the vertical direction. As described above, the configurations and methods described in this specification can be appropriately combined within a range where they do not conflict with each other.

Explanation of Signs

[0109] 10…Rotating electrical machine, 20…Motor housing (housing), 27…Axial gap, 30…Rotor, 31…Shaft, 31a…First shaft portion, 35…Bearing, 40…Stator, 60…Gear mechanism, 70…Nozzle member, 70a…Nozzle through-hole, 71…Supply cylinder portion, 72…Flange portion, 73…Projecting cylinder portion, 74…Through portion, 80…Static eliminator, 93a…First flow path portion (housing flow path portion), 100…Drive device, 110…Second shaft portion, 111…Cover portion, 112…Extension portion, 113…First recess (recess), 115…Connecting flow path portion, 120…Sealing member, J…Central axis

Claims

1. A rotor having a hollow shaft rotatable about a central axis, A stator facing the rotor with a gap therebetween, A housing that houses the rotor and the stator therein, A bearing that rotatably supports the shaft, A static eliminator fixed to the housing and electrically contacting the shaft and the housing, A housing flow path portion provided in the housing, A nozzle member having a nozzle through-hole connected to the inside of the shaft, A seal member positioned between the shaft and the housing in the radial direction, Comprising, The shaft, A hollow first shaft portion, A second shaft portion having a lid portion provided at one axial side of the first shaft portion and an extension portion extending axially from the lid portion, Having, The extension portion is axially passed through the nozzle through-hole, The static eliminator contacts a portion of the extension portion that is located axially on one side of the nozzle through-hole, The seal member is located axially on one side of the nozzle member and axially on the other side of the static eliminator, The shaft has a connection flow path portion that connects the inside of the first shaft portion and the inside of the nozzle through-hole, The housing flow path portion opens toward an axial gap between the nozzle member and the seal member inside the housing, a rotating electrical machine.

2. A part of the nozzle member axially faces the bearing, The nozzle member has a through-hole that axially penetrates a portion of the nozzle member that axially faces the bearing, the rotating electrical machine according to Claim 1.

3. The flow path cross-sectional area of the connection flow path portion increases as it approaches the inside of the first shaft portion, the rotating electrical machine according to Claim 1 or 2.

4. The connection flow path portion is provided in the lid portion, the rotating electrical machine according to any one of Claims 1 to 3.

5. The lid portion has a recess that depresses axially from a surface on one axial side of the lid portion to the other axial side, The nozzle member has a supply cylinder portion that constitutes the nozzle through-hole, An end portion on the other axial side of the supply cylinder portion is located within the recess, The connection flow path portion opens into the recess and is connected to the inside of the nozzle through-hole through the inside of the recess, the rotating electrical machine according to Claim 4.

6. The rotating electrical machine according to claim 5, wherein the connection flow path portion opens across a surface located on the other axial side of the inner surface of the concave portion and a surface located on the outer radial side of the inner surface of the concave portion.

7. The extension portion extends axially on one side from a surface located on the other axial side of the inner surface of the concave portion. The rotating electrical machine according to claim 5 or 6, wherein a plurality of the connection flow path portions are provided so as to surround the extension portion when viewed axially.

8. The nozzle member has a flange portion that spreads radially outward from the supply cylinder portion and is disposed to face one axial side of the bearing, and a protruding cylinder portion that protrudes axially on the other side from the outer radial edge portion of the flange portion. The rotating electrical machine according to any one of claims 5 to 7.

9. The rotating electrical machine according to any one of claims 4 to 8, wherein the lid portion overlaps the bearing in the radial direction.

10. The rotating electrical machine according to claim 9, wherein an axial position at an end on one axial side of the lid portion is the same as an axial position at an end on one axial side of the bearing.

11. A drive device comprising: the rotating electrical machine according to any one of claims 1 to 10; and a gear mechanism connected to the rotating electrical machine.

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