WO2023189034A1

WO2023189034A1 - Drive device

Info

Publication number: WO2023189034A1
Application number: PCT/JP2023/006404
Authority: WO
Inventors: 優海杉野; 直大和田; 祐輔牧野; 啓介麻生; 祥平大菅
Original assignee: ニデック株式会社
Priority date: 2022-03-31
Filing date: 2023-02-22
Publication date: 2023-10-05

Abstract

One embodiment of this drive device comprises: a motor having a first shaft; a power transmission unit having a second shaft; a housing; and a flow channel through which a fluid flows. The first shaft and the second shaft are mutually connected by engagement between a spline groove in a recess section and a spline protrusion of a protrusion section. The housing is provided with a dividing wall that partitions the interior of the housing into a motor chamber and a gear chamber. The dividing wall is provided with an interconnecting hole interconnecting the motor chamber and the gear chamber. An inner peripheral surface of the interconnecting hole holds a first bearing and a second bearing. An interconnecting space to which the recess section is open is provided in an interval in the axial direction between the first bearing and the second bearing in the interconnecting hole. The flow channel inlcudes: a first flow channel linking a first storage part to the interconnecting space; a second flow channel linking the interconnecting space to the inside of the recess section; and a third flow channel linking the interconnecting space to a second storage part.

Description

drive device

The present invention relates to a drive device.
This application claims priority based on Japanese Patent Application No. 2022-061134 filed in Japan on March 31, 2022, the contents of which are incorporated herein.

In recent years, the development of a drive device that combines a motor and a speed reduction device into a unit has been progressing as a drive device installed in an electric vehicle. In such a drive device, the shaft on the motor side and the shaft of the speed reducer are connected by meshing of the spline grooves and the spline protrusions with each other. Patent Document 1 discloses a structure in which the shafts on the motor side and the speed reducer side are hollow shafts, and oil is supplied to the connecting portion by flowing oil into the hollow shafts.

JP2017-75627A

When oil flows into the hollow shaft, a flow path is required to return the oil that has reached the space on the motor side in the housing to the gear side, which complicates the structure of the housing. Therefore, there is a need for a structure that can supply fluid to the coupling portion of the shaft without using a hollow shaft.

In view of the above circumstances, one of the objects of the present invention is to provide a drive device that can supply fluid to a connecting portion between shafts.

One aspect of the drive device of the present invention includes a rotor having a first shaft that rotates around a central axis, a motor having a stator surrounding the rotor, a plurality of gears, and a first shaft that rotates around the central axis. a housing that has two shafts and is provided with a power transmission section that transmits the power of the motor, a motor chamber that accommodates the motor, and a gear chamber that accommodates the power transmission section; and a housing that supports the first shaft. A second bearing that supports the second shaft, a flow path through which fluid flows, and a first storage section and a second storage section in which the fluid is stored. One of the axially one end of the first shaft and the other axially end of the second shaft has a recess in which a plurality of axially extending spline grooves are provided in the inner circumferential surface. The other has a convex portion provided with a plurality of spline protrusions extending in the axial direction on the outer circumferential surface and inserted into the concave portion. The first shaft and the second shaft are connected to each other by engagement between the spline groove of the recess and the spline protrusion of the convex part. The housing has a partition wall that partitions the motor chamber and the gear chamber. The partition wall is provided with a communication hole that communicates the motor chamber and the gear chamber. The inner peripheral surface of the communication hole holds the first bearing and the second bearing. A connection space in which the recess opens is provided between the first bearing and the second bearing in the communication hole in the axial direction. The flow path includes a first flow path that connects the first storage section and the connection space, a second flow path that connects the connection space and the inside of the recess, and a connection space and the second storage section. and a third flow path connecting the. The fluid flows into the first flow path, the second flow path, and the third flow path.

According to one aspect of the present invention, it is possible to provide a drive device that is capable of supplying fluid to a connecting portion between shafts.

FIG. 1 is a conceptual diagram of a drive device according to an embodiment. FIG. 2 is a front view of the gear chamber of one embodiment viewed from one side in the axial direction. FIG. 3 is a rear view of the gear chamber of one embodiment viewed from the other axial side. FIG. 4 is a cross-sectional view of a connecting portion of a first shaft and a second shaft in one embodiment. FIG. 5 is a partial cross-sectional view of a coupling portion of one embodiment. FIG. 6 is a cross-sectional view of a connecting portion of a first shaft and a second shaft in a modified example.

In the following explanation, the direction of gravity will be defined and explained based on the positional relationship when the drive device 1 is mounted on a vehicle located on a horizontal road surface. In addition, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system.

In the XYZ coordinate system, the Z-axis direction indicates the vertical direction (that is, the up-down direction), the +Z direction is the upper side (opposite to the direction of gravity), and the -Z direction is the lower side (the direction of gravity). Moreover, the X-axis direction is a direction orthogonal to the Z-axis direction, and indicates the front-rear direction of the vehicle in which the drive device 1 is mounted. In the following embodiments, the side to which the X-axis arrow points (+X side) is the front side of the vehicle, and the side opposite to the side to which the X-axis arrow points (-X side) is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and indicates the width direction (left-right direction) of the vehicle. In the following embodiments, the side to which the Y-axis arrow points (+Y side) is the left side of the vehicle, and the side opposite to the side to which the Y-axis arrow points (-Y side) is the right side of the vehicle. The front-rear direction and the left-right direction are horizontal directions perpendicular to the vertical direction.

In the following description, unless otherwise specified, the direction parallel to the central axis J1 of the motor 2 (Y-axis direction) is simply referred to as the "axial direction", and the radial direction centered on the central axis J1 is simply referred to as the "radial direction". The circumferential direction centered on the central axis J1, that is, the circumferential direction around the central axis J1 is simply referred to as the "circumferential direction." However, the above-mentioned "parallel direction" also includes substantially parallel directions. Furthermore, in the following description, among the axial directions of the central axis J1, the -Y direction may be simply referred to as one axial direction, and the +Y direction may simply be referred to as the other axial direction.

<Drive device>
FIG. 1 is a conceptual diagram of a drive device 1 of this embodiment.
The drive device 1 of this embodiment is mounted on a vehicle that uses a motor as a power source, such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV), and is used as the power source.

As shown in FIG. 1, the drive device 1 includes a motor 2, a power transmission section 4, an inverter 7, a housing 6, and a plurality of

bearings

5A, 5B, 5C, 5D, 5E, 5F, 5G, and 5H. Housing 6 accommodates motor 2, power transmission section 4, inverter 7, and a plurality of bearings 5A to 5H. Inside the housing 6, the motor 2, the power transmission section 4, and the inverter 7 are arranged on the central axis J1. In the following description, the plurality of bearings 5A to 5H are respectively referred to as a first bearing 5A, a second bearing 5B, a third bearing 5C, a fourth bearing 5D, a fifth bearing 5E, a sixth bearing 5F, a seventh bearing 5G, and 8th bearing 5H.

<Motor>
The motor 2 of this embodiment is an inner rotor type three-phase AC motor. The motor 2 functions both as an electric motor and as a generator. Note that the configuration of the motor 2 is not limited to this embodiment, and may be, for example, a four-phase or more AC motor.

The motor 2 is arranged in the motor chamber R1 of the housing 6. The motor 2 includes a rotor 20 and a stator 30 that faces the rotor 20 in the radial direction. The motor 2 of this embodiment is an inner rotor type motor in which a rotor 20 is arranged inside a stator 30.

The rotor 20 rotates around a central axis J1 that extends in the horizontal direction. The rotor 20 includes a first shaft 21, a rotor core 24 fixed to the outer peripheral surface of the first shaft 21, and a rotor magnet (not shown) fixed to the rotor core 24. The torque of the rotor 20 is transmitted to the power transmission section 4. The first shaft 21 extends in the axial direction centering on the central axis J1. The first shaft 21 rotates around the central axis J1. Both ends of the first shaft 21 are rotatably supported by a first bearing 5A and a third bearing 5C.

The rotor 20 of this embodiment is provided with a pair of fans 25. The fan 25 rotates together with the rotor 20 around the central axis J1. One of the pair of fans 25 is fixed to the end surface of the rotor core 24 on one axial side, and the other is fixed to the end surface of the rotor core 24 on the other axial side. One fan 25 faces each coil end of the stator 30. The fan 25 sends air radially outward. The fan 25 circulates air within the motor room R1. According to this embodiment, the motor 2 can be cooled by the wind generated by the fan 25 without directly applying refrigerant to the motor 2. According to this embodiment, the seal structure of the motor chamber R1 can be simplified.

The stator 30 is held in the housing 6. The stator 30 surrounds the rotor 20 from the outside in the radial direction. The stator 30 includes an annular stator core 32 centered on the central axis J1, a coil 31 attached to the stator core 32, and an insulator (not shown) interposed between the stator core 32 and the coil 31. The stator core 32 has a plurality of magnetic pole teeth (not shown) radially inward from the inner peripheral surface of the annular yoke. A coil wire is arranged between the magnetic pole teeth. The coil wire located within the gap between adjacent magnetic pole teeth constitutes the coil 31. The insulator is made of an insulating material.

<Inverter>
Inverter 7 is electrically connected to motor 2 . The inverter 7 is connected to a battery (not shown) mounted on the vehicle, converts direct current supplied from the battery into alternating current, and supplies the alternating current to the motor 2. Further, the inverter 7 controls the motor 2. The inverter 7 of this embodiment is arranged on the other axial side (+Y side) with respect to the motor 2. According to this embodiment, the drive device 1 can be made smaller in the radial direction compared to the case where the inverter 7 is arranged outside the motor 2 in the radial direction.

<Power transmission section>
The power transmission section 4 is arranged on one axial side (-Y side) with respect to the motor 2. The power transmission section 4 is connected to the rotor 20 and transmits the power of the motor 2, and outputs the power to the output shaft 47. The power transmission section 4 includes a reduction gear 4a and a differential gear 4b. That is, the drive device 1 includes a speed reduction device 4a and a differential device 4b.

The torque output from the motor 2 is transmitted to the differential gear 4b via the reduction gear 4a. In the reduction gear device 4a of this embodiment, the rotational axes of each gear are arranged in parallel. The differential device 4b transmits the same torque to both the left and right wheels while absorbing the speed difference between the left and right wheels when the vehicle turns.

The reduction gear 4a has a second shaft 44, a third shaft 45, a first gear 41, a second gear 42, and a third gear 43. The differential device 4b includes a ring gear 46g, a differential case 46, and a differential mechanism section 46c disposed inside the differential case 46. That is, the power transmission section 4 includes a plurality of

gears

41, 42, 43, 46g and a plurality of

shafts

44, 45.

The second shaft 44 extends in the axial direction centering on the central axis J1. The second shaft 44 is arranged coaxially with the first shaft 21. The second shaft 44 is connected to the end of the first shaft 21 on the one axial side (-Y side) at the end on the other axial side (+Y side). The second shaft 44 rotates together with the first shaft 21 about the central axis J1. The second shaft 44 is rotatably supported by the second bearing 5B and the fourth bearing 5D.

The first gear 41 is fixed to the outer peripheral surface of the second shaft 44. The first gear 41 rotates together with the second shaft 44 around the central axis J1.

The third shaft 45 rotates around an intermediate axis J2 that is parallel to the central axis J1. The third shaft 45 is rotatably supported by the fifth bearing 5E and the sixth bearing 5F.

The second gear 42 and the third gear 43 are arranged side by side in the axial direction. The second gear 42 and the third gear 43 are provided on the outer peripheral surface of the third shaft 45. The second gear 42 and the third gear 43 are connected via a third shaft 45. The second gear 42 and the third gear 43 rotate about the intermediate axis J2. The second gear 42 meshes with the first gear 41. The third gear 43 meshes with a ring gear 46g of the differential device 4b. In this embodiment, the first gear 41, the second gear 42, the third gear 43, and the ring gear 46g are each helical gears.

The ring gear 46g rotates around an output axis J3 that is parallel to the central axis J1. Torque output from the motor 2 is transmitted to the ring gear 46g via the reduction gear 4a. Ring gear 46g is fixed to differential case 46.

The differential case 46 includes a case portion 46b that accommodates a differential mechanism portion 46c therein, and a differential case shaft 46a that protrudes to the other side and the other side in the axial direction with respect to the case portion 46b. That is, the power transmission section 4 includes a differential case shaft 46a. The differential case shaft 46a has a cylindrical shape that extends in the axial direction centering on the output axis J3. The differential case shaft 46a is rotatably supported by a seventh bearing 5G and an eighth bearing 5H. Ring gear 46g is provided on the outer peripheral surface of differential case shaft 46a. The differential case shaft 46a rotates together with the ring gear 46g about the output axis J3.

The pair of output shafts 47 are connected to the differential gear 4b. The pair of output shafts 47 protrude from the differential case 46 of the differential device 4b to the other side in the axial direction and to the other side. The output shaft 47 is arranged inside the differential case shaft 46a. The output shaft 47 is rotatably supported on the inner peripheral surface of the differential case shaft 46a via a bearing (not shown).

The torque output from the motor 2 is transmitted to the ring gear 46g of the differential device 4b via the second shaft 44, first gear 41, second gear 42, third shaft 45, and third gear 43 of the motor 2, It is output to the output shaft 47 via the differential mechanism section 46c of the differential device 4b. The plurality of

gears

41, 42, 43, and 46g of the power transmission section 4 transmit the power of the motor 2 to the second shaft 44, the third shaft 45, and the differential case shaft 46a in this order.

<Housing>
The housing 6 includes a first housing member 6A, a second housing member 6B, a third housing member 6C, a water jacket 6D, and a bearing holder 6E. The first housing member 6A, the second housing member 6B, the third housing member 6C, the water jacket 6D, and the bearing holder 6E are each separate members. The first housing member 6A is arranged on the other axial side (+Y side) of the second housing member 6B. The third housing member 6C is arranged on one axial side (-Y side) of the second housing member 6B. The water jacket 6D and the bearing holder 6E are arranged inside the second housing member 6B.

The housing 6 is provided with a circulation channel 90 through which the cooling water L flows. The cooling water L is, for example, water. The circulation waterway 90 includes an external pipe 97 that passes through the outside of the housing 6, and a first waterway 91, a second waterway 92, a third waterway (waterway) 93, and a fourth waterway 94 that pass through the inside of the housing 6. include. A radiator (not shown) that cools the cooling water L is arranged in the path of the external piping 97.

The cooling water L flows inside the housing 6 in the order of the first water channel 91 , the second water channel 92 , the third water channel 93 , and the fourth water channel 94 . The first water channel 91 is provided in the first housing member 6A. The first water channel 91 is connected to an external pipe 97. The cooling water L mainly cools the inverter 7 in the first water channel 91 . The second water channel 92 is provided in the second housing member 6B. The second waterway 92 connects the first waterway 91 and the third waterway 93. The third water channel 93 is provided along the outer peripheral surface of the water jacket 6D. The cooling water L mainly cools the motor 2 in the third water channel 93. The fourth water channel 94 is provided in the second housing member 6B. The fourth water channel 94 is connected to an external pipe 97.

The second housing member 6B accommodates the motor 2 and opens on the other axial side (+Y side). The second housing member 6B includes a cylindrical outer cylindrical portion 65 centered on the central axis J1, and is arranged on one axial side (−Y side) of the outer cylindrical portion 65 and is located on one axial side of the outer cylindrical portion 65. It has a partition wall 65a that covers the opening, and a first peripheral wall portion 65b that extends from the outer edge of the partition wall 65a to one side in the axial direction (-Y side). That is, the housing 6 has a partition wall 65a.

A communication hole 65h is provided in the partition wall 65a. A first bearing 5A, a second bearing 5B, and a seal member 5S are arranged inside the communication hole 65h. The first shaft 21 and the second shaft 44 are connected to each other inside the communication hole 65h. The configuration of the communication hole 65h will be described in detail later based on FIG. 4.

The outer cylindrical portion 65 surrounds the motor 2 from the outside in the radial direction. The outer cylindrical portion 65 supports the stator 30 via the water jacket 6D. The outer cylinder portion 65 is provided with a second water channel 92 extending in the axial direction and a fourth water channel 94 extending in the radial direction.

The third housing member 6C is arranged on one axial side (-Y side) of the second housing member 6B. The third housing member 6C includes an opposing wall 67 that faces the partition wall 65a, and a second peripheral wall portion 67a extending from the outer edge of the opposing wall 67 toward the other axial side (+Y side). The end face of the second peripheral wall portion 67a on the other axial side (+Y side) is fastened to the end face of the first peripheral wall portion 65b on the one axial side (−Y side).

The first housing member 6A holds the inverter 7. The first housing member 6A covers the opening on the other axial side (+Y side) of the outer cylinder portion 65 of the second housing member 6B.

The water jacket 6D has a cylindrical inner cylinder part 64 centered on the central axis J1, and a protruding rib 64a provided on the outer peripheral surface of the inner cylinder part 64. The inner cylinder portion 64 surrounds the stator 30 from the outside in the radial direction. The inner diameter of the inner cylindrical portion 64 substantially matches the outer diameter of the stator core 32.

The inner circumferential surface of the inner cylindrical portion 64 contacts the outer circumferential surface of the stator 30. Moreover, the inner cylinder part 64 is surrounded by the outer cylinder part 65 from the outside in the radial direction. The outer diameter of the inner cylindrical portion 64 is smaller than the inner diameter of the outer cylindrical portion 65 of the second housing member 6B. A gap is provided between the inner cylindrical portion 64 and the outer cylindrical portion 65, which functions as a third water channel 93.

The protruding rib 64a extends spirally around the central axis J1. The protruding rib 64a has a tip located at the radially outer end. The tip of the protruding rib 64a contacts the inner circumferential surface of the outer cylindrical portion 65, or faces the inner circumferential surface of the outer cylindrical portion 65 with a slight gap therebetween. Thereby, the protruding rib 64a partitions off the gap between the inner cylindrical portion 64 and the outer cylindrical portion 65, and forms the third water channel 93 in a spiral shape.

According to this embodiment, the housing 6 is provided with a third water channel 93 that extends along the outer peripheral surface of the stator 30. According to this embodiment, the stator 30 can be cooled by the cooling water L flowing through the third water channel 93 without directly applying refrigerant to the stator 30 . According to this embodiment, the seal structure of the motor chamber R1 can be simplified.

In this embodiment, the case where the third water channel 93 extends spirally has been described. However, the third water channel 93 is not limited to this embodiment as long as it surrounds the stator 30. The third water channel 93 may be a meandering channel in the axial direction or the circumferential direction. The flow path configuration of the third water channel 93 can be determined by the shape of the protruding rib 64a.

The bearing holder 6E is arranged on the other axial side (+Y side) of the motor 2 inside the second housing member 6B. The bearing holder 6E is fixed to the end face of the water jacket 6D on the other axial side (+Y side). The bearing holder 6E holds a third bearing 5C that rotatably supports the rotor 20.

Inside the housing 6, a motor chamber R1 that accommodates the motor 2, a gear chamber R2 that accommodates the power transmission section 4, and an inverter chamber R3 that accommodates the inverter 7 are provided. The gear chamber R2, the motor chamber R1, and the inverter chamber R3 are arranged in this order from one axial side (-Y side) to the other axial side (+Y side). The motor chamber R1 and the gear chamber R2 are partitioned by a partition wall 65a. Motor chamber R1 and inverter chamber R3 are partitioned by bearing holder 6E.

The motor chamber R1 is a space surrounded from the outside in the radial direction by the inner cylinder portion 64 and sandwiched in the axial direction by the partition wall 65a and the bearing holder 6E.

The inverter chamber R3 is a space surrounded from the outside in the radial direction by the outer cylinder portion 65 and sandwiched in the axial direction by the bearing holder 6E and the first housing member 6A.

The motor chamber R1 and the inverter chamber R3 communicate with each other via a through hole provided in the bearing holder 6E. A breather 63 is provided in the outer cylindrical portion 65 surrounding the inverter chamber R3. Breather 63 communicates motor chamber R1 and inverter chamber R3 with the outside of housing 6. Breather 63 suppresses the pressure in motor chamber R1 and inverter chamber R3 from increasing too much.

The gear chamber R2 is a space surrounded by the first circumferential wall portion 65b and the second circumferential wall portion 67a in the radial direction, and sandwiched between the partition wall 65a and the opposing wall 67 in the axial direction. The gear chamber R2 is arranged on one axial side (-Y side) of the motor chamber R1.

A fluid O is stored in the gear chamber R2. The fluid O is, for example, oil. In this embodiment, the fluid O is used as a lubricating oil for the power transmission section 4 and the bearings. As the fluid O, for example, in order to perform the functions of a refrigerant and a lubricant, it is preferable to use an oil equivalent to automatic transmission fluid (ATF), which has a relatively low viscosity.

The housing 6 is provided with a fluid path 50 through which the fluid O passes.
Note that in this specification, the term "fluid path" means a path for the fluid O circulating within the housing 6. Therefore, the term "fluid path" refers not only to a tubular flow path that forms a steady flow of fluid O that constantly goes in one direction, but also to a path that temporarily retains fluid O (for example, a storage section), a fluid This concept also includes a path through which O drips and a path through which fluid O scatters.

The fluid path 50 includes a first raking path 58, a second raking path 59, a first supply path 51, a second supply path (flow path) 52, a third supply path 53, and a second raking path 59. It has a fourth supply flow path 54 and a fifth supply flow path 55. Further, in the fluid path 50, a first storage section 84, a second storage section 82, and a third storage section B (see FIG. 4) are arranged. That is, the drive device 1 includes a first scraping path 58, a second scraping path 59, a first supply channel 51, a second supply channel 52, a third supply channel 53, a fourth supply channel 54, and a 5 supply channel 55, a first storage section 84, a second storage section 82, and a third storage section B. Fluid O flows through the first supply channel 51 , the second supply channel 52 , the third supply channel 53 , the fourth supply channel 54 , and the fifth supply channel 55 . Further, fluid O is accumulated in the first storage section 84 and the second storage section 82 .

The first storage portion 84 is arranged in the gear chamber R2. The first storage section 84 is a catch tank that opens upward. The first storage section 84 receives the fluid O scooped up by each gear (for example, the ring gear 46g and the second gear 42) of the power transmission section 4 within the gear chamber R2.

FIG. 2 is a front view of the gear chamber R2 viewed from one axial side (-Y side). FIG. 3 is a rear view of the gear chamber R2 viewed from the other axial side (+Y side).
As shown in FIGS. 2 and 3, the first storage portion 84 of this embodiment includes a first rib 84d that protrudes from the partition wall 65a to one axial side (-Y side), and a first rib 84d that protrudes from the opposite wall 67 to the other axial side (-Y side). +Y side). The first rib 84d and the second rib 84e are connected with their end surfaces in contact with each other.

As shown in FIG. 1, the second storage portion 82 is a fluid reservoir provided in the lower region of the gear chamber R2. That is, the second storage section 82 in which the fluid O is stored is provided in the lower region of the gear chamber R2. A lower end of the ring gear 46g and a lower end of the second gear 42 are located within the second storage portion 82. Therefore, the ring gear 46g and a portion of the second gear 42 are immersed in the fluid O accumulated in the second storage section 82.

The first scooping path 58 scrapes up the fluid O in the second storage section 82 and transfers it to the first storage section 84 by the rotation of the gears of the power transmission section 4 (in this embodiment, the ring gear 46g and the second gear 42). It is a path that leads. By transferring the fluid O from the second storage section 82 to the first storage section 84 through the first scooping path 58, the amount of storage in the first storage section 84 increases, and the liquid level of the fluid O in the first storage section 84 increases. Go down. According to this embodiment, by storing the fluid O in the first storage part 84, the liquid level in the second storage part 82 can be lowered and the stirring resistance of the power transmission part 4 caused by the fluid O can be reduced.

The second scooping path 59 scoops up the fluid O in the second storage section 82 and supplies it to the eighth bearing 5H by the rotation of the gears of the power transmission section 4 (in this embodiment, the ring gear 46g and the second gear 42). This is the route to

As shown in FIG. 3, the first supply channel 51 and the third supply channel 53 are provided on the opposing wall 67 of the third housing member 6C. The first supply channel 51 extends from the first storage section 84 toward the outer peripheral surface of the fourth bearing 5D. The first supply channel 51 supplies the fluid O in the first storage section 84 to the fourth bearing 5D. The third supply channel 53 extends from the first storage section 84 toward the outer peripheral surface of the sixth bearing 5F. The third supply channel 53 supplies the fluid O in the first storage section 84 to the sixth bearing 5F.

As shown in FIG. 2, the second supply flow path 52, the fourth supply flow path 54, and the fifth supply flow path 55 are provided in the partition wall 65a of the second housing member 6B. The second supply channel 52 extends from the first storage section 84 toward the inner peripheral surface of the communication hole 65h. The configuration of the second supply channel 52 will be described in detail later.

The fourth supply flow path 54 extends from the first storage section 84 toward the outer peripheral surface of the fifth bearing 5E. The fourth supply channel 54 supplies the fluid O in the first storage section 84 to the fifth bearing 5E. The fifth supply channel 55 extends from the first storage section 84 toward the outer peripheral surface of the seventh bearing 5G. The fifth supply channel 55 supplies the fluid O in the first storage section 84 to the seventh bearing 5G.

<Communication hole>
FIG. 4 is a sectional view of the first shaft 21 and the second shaft 44 arranged in the communication hole 65h.
The communication hole 65h communicates the motor chamber R1 and the gear chamber R2. The inner circumferential surface of the communication hole 65h is circular centered on the central axis J1. The inner peripheral surface of the communication hole 65h holds the first bearing 5A, the second bearing 5B, and the seal member 5S.

The partition wall 65a has a cylindrical portion 11 that protrudes toward the gear chamber R2 side (ie, one axial side (-Y side)) along the inner edge of the communication hole 65h. The cylindrical portion 11 has a cylindrical shape centered on the central axis J1. The cylindrical portion 11 surrounds and holds the first bearing 5A and the second bearing 5B. In this specification, the inner circumferential surface of the cylindrical portion 11 is the inner circumferential surface of the communication hole 65h. By providing the cylindrical portion 11 on the partition wall 65a, the inner peripheral surface of the communication hole 65h can be extended along the axial direction. Thereby, a plurality of bearings can be stably held on the inner peripheral surface of the communication hole 65h.

The inner circumferential surface of the communication hole 65h includes a first inner circumferential surface 66a, a second inner circumferential surface 66b, a third inner circumferential surface 66c, a fourth inner circumferential surface 66d, a first stepped surface 66e, a second stepped surface 66f, and a third inner circumferential surface 66c. It has a three-step surface 66g. The first inner circumferential surface 66a, the second inner circumferential surface 66b, the third inner circumferential surface 66c, and the fourth inner circumferential surface 66d extend from the other axial side (+Y side) to the one axial side (-Y side). Line up in the order of levers.

The first inner peripheral surface 66a surrounds the outer peripheral surface of the first bearing 5A. The first inner peripheral surface 66a holds the first bearing 5A. The diameter of the first inner peripheral surface 66a is larger than the diameter of the second inner peripheral surface 66b. A first step surface 66e facing the other axial side (+Y side) is provided between the first inner circumferential surface 66a and the second inner circumferential surface 66b. The outer ring 5Aa of the first bearing 5A is pressed against the first step surface 66e. The first bearing 5A supports the first shaft 21.

A seal member 5S is held on the second inner circumferential surface 66b. The second inner peripheral surface 66b holds the seal member 5S. The diameter of the second inner circumferential surface 66b is larger than the diameter of the third inner circumferential surface 66c. Therefore, there is a gap between the second inner circumferential surface 66b and the third inner circumferential surface 66c on the other side in the axial direction (+Y side). ) is provided. The seal member 5S contacts and is aligned with the second step surface 66f.

The third inner peripheral surface 66c has the smallest diameter on the inner peripheral surface of the communication hole 65h. The third inner circumferential surface 66c surrounds a connection space A, which will be described later, from the outside in the radial direction.

The fourth inner peripheral surface 66d surrounds the outer peripheral surface of the second bearing 5B. The fourth inner peripheral surface 66d holds the second bearing 5B. The diameter of the fourth inner peripheral surface 66d is larger than the diameter of the third inner peripheral surface 66c. A third step surface 66g facing one side in the axial direction (-Y side) is provided between the fourth inner circumferential surface 66d and the third inner circumferential surface 66c. The outer ring 5Ba of the second bearing 5B is pressed against the third step surface 66g. The second bearing 5B supports the second shaft 44.

The end of the first shaft 21 on one axial side (-Y side) has a recess 21a. The recess 21a has a circular shape centered on the central axis J1 when viewed from the axial direction. The recess 21a has a bottom surface 21b facing one side in the axial direction (-Y side) and an inner circumferential surface facing inward in the radial direction. A plurality of spline grooves 21s are provided on the inner peripheral surface of the recess 21a. The plurality of spline grooves 21s extend in the axial direction. The plurality of spline grooves 21s are arranged along the circumferential direction.

The end of the second shaft 44 on the other axial side (+Y side) has a convex portion 44a. The convex portion 44a has a cylindrical shape centered on the central axis J1. The convex portion 44a has a distal end surface 44b facing the other side in the axial direction (+Y side) and an outer circumferential surface facing outward in the radial direction. A plurality of spline protrusions 44s are provided on the outer peripheral surface of the convex portion 44a. The plurality of spline protrusions 44s extend in the axial direction. The plurality of spline protrusions 44s are arranged along the circumferential direction.

FIG. 5 is a cross-sectional view showing a connecting portion between the concave portion 21a and the convex portion 44a.
The first shaft 21 and the second shaft 44 are connected to each other by engagement between the spline groove 21s of the recess 21a and the spline protrusion 44s of the convex portion 44a. In the following description, the portion where the spline groove 21s and the spline protrusion 44s engage and are connected will be referred to as a connecting portion 3.

The spline groove 21s has a uniform cross-sectional shape and extends along the axial direction. Similarly, the spline protrusion 44s has a uniform cross-sectional shape and extends in the axial direction. One spline projection 44s is inserted into one spline groove 21s. The diameter of the bottom surface of the spline groove 21s facing radially inward is larger than the diameter of the tip surface facing radially outside of the spline protrusion 44s. Moreover, the width dimension of the spline groove 21s is larger than the width dimension of the spline protrusion 44s. Therefore, a gap 3a is provided between the inner surface of the spline groove 21s and the outer surface of the spline projection 44s. The fluid O mutually moves between one end and the other end of the connecting portion 3 in the axial direction through the gap 3a.

As shown in FIG. 4, in this embodiment, an axial gap is provided between the bottom surface 21b of the recess 21a and the tip surface 44b of the convex portion 44a. In the following description, the gap between the bottom surface 21b and the tip surface 44b will be referred to as a third storage section B. That is, the third reservoir B is provided between the bottom surface 21b and the tip surface 44b. The third storage portion B is a space surrounded from the outside in the radial direction by the inner circumferential surface of the recess 21a and sandwiched in the axial direction by the bottom surface 21b and the tip surface 44b. The fluid O remains in the third reservoir B.

Relative movement of the first shaft 21 and the second shaft 44 in the circumferential direction is restricted at the connecting portion 3. Therefore, the first shaft 21 and the second shaft 44 rotate synchronously around the central axis J1. Further, the first shaft 21 and the second shaft 44 allow relative movement in the axial direction in the connecting portion 3.

In this embodiment, helical gears can be employed as the first gear 41 and the second gear 42. Therefore, the first gear 41 receives a reaction force directed in the axial direction from the second gear 42 during driving. According to the present embodiment, since the first shaft 21 and the second shaft 44 are relatively movable in the axial direction in the connecting portion 3, the axial force applied to the first gear 41 is It is possible to suppress the transmission of the heat to the first shaft 21 via the portion 3 . Therefore, it is possible to suppress a large thrust load from being applied to the

bearings

5A, 5C that support the second shaft 44.

The end of the first shaft 21 on one axial side (−Y side) has a stepped shape that becomes narrower toward the tip. The first shaft 21 has a first outer peripheral surface 21d, a second outer peripheral surface 21e, and a third outer peripheral surface 21f. The first outer circumferential surface 21d, the second outer circumferential surface 21e, and the third outer circumferential surface 21f are arranged in this order from the other axial side (+Y side) to the one side. The diameters of the first outer circumferential surface 21d, the second outer circumferential surface 21e, and the third outer circumferential surface 21f decrease in this order.

The second outer peripheral surface 21e faces the first inner peripheral surface 66a of the communication hole 65h in the radial direction. The first bearing 5A is mounted on the second outer peripheral surface 21e. That is, the second outer peripheral surface 21e is surrounded by the first bearing 5A. A fourth step surface 21g facing one side in the axial direction (-Y side) is provided between the second outer peripheral surface 21e and the first outer peripheral surface 21d. The inner ring 5Ac of the first bearing 5A is pressed against the fourth step surface 21g.

The third outer circumferential surface 21f is located at one end of the first shaft 21 in the axial direction (-Y side). The third outer peripheral surface 21f faces the second inner peripheral surface 66b of the communication hole 65h in the radial direction. The inner end of the seal member 5S contacts the third outer peripheral surface 21f. As the first shaft 21 rotates, the third outer peripheral surface 21f slides on the seal member 5S.

A connection space A is provided between the first bearing 5A and the second bearing 5B in the axial direction in the communication hole 65h. In this embodiment, the space between the first bearing 5A and the second bearing 5B in the axial direction is divided into two by the seal member 5S. The connecting space A of this embodiment is one of the two spaces defined by the seal member 5S on one side in the axial direction (-Y side) where the recess 21a opens. That is, the recess 21a opens in the connection space A. The connection space A of this embodiment is sandwiched between the third inner circumferential surface 66c of the communication hole 65h and the outer circumferential surface of the second shaft 44 in the radial direction, and between the second bearing 5B and the seal member 5S in the axial direction. . A fluid O is supplied to the connection space A through a first flow path 52a of a second supply flow path 52, which will be described later.

Note that in this specification, the connection space A does not include the insides of the first shaft 21 and the second shaft 44. The connection space A is a space radially inside the inner peripheral surface of the communication hole 65h and radially outside the outer peripheral surfaces of the first shaft 21 and the second shaft 44. That is, the connection space A is located between the first bearing 5A and the second bearing 5B in the communication hole 65h in the axial direction, and between the inner peripheral surface of the communication hole 65h, the outer peripheral surface of the first shaft 21, and the outer peripheral surface of the second shaft 44. It is provided between the surface and the surface in the radial direction.

A seal member 5S is provided in the communication hole 65h of this embodiment. The seal member 5S seals the gap between the inner peripheral surface of the communication hole 65h and the outer peripheral surface of the first shaft 21. According to this embodiment, it is possible to seal between the motor chamber R1 and the gear chamber R2, and it is possible to suppress the fluid O from entering the motor chamber R1. Thereby, the seal structure of the motor chamber R1 can be simplified. Moreover, since the seal member 5S retains the fluid O in the connection space A, a large amount of fluid O can be supplied to the connection portion 3 and the second bearing 5B.

According to this embodiment, the seal member 5S is located between the first bearing 5A and the second bearing 5B. Moreover, in this embodiment, the connection space A is provided between the seal member 5S and the second bearing 5B. Since the fluid O is supplied to the connection space A, the fluid O comes into contact with the sealing member 5S. According to this embodiment, it is possible to lubricate the space between the seal member 5S and the third outer circumferential surface 21f of the first shaft 21, and the sliding resistance of the seal member 5S can be suppressed.

As shown as a modification in FIG. 6, the seal member 105S may be arranged on the other axial side (+Y side) of the first bearing 5A and the second bearing 5B. In this case, the fluid O flowing into the connection space A touches not only the second bearing 5B but also the first bearing 5A, and can lubricate the first bearing 5A.

As shown in FIG. 4, according to the present embodiment, the seal member 5S is held on the inner peripheral surface of the communication hole 65h and contacts the outer peripheral surface of the first shaft 21. Further, in the first shaft 21, the outer diameter of the portion (third outer circumferential surface 21f) in contact with the seal member 5S is smaller than the outer diameter of the portion (second outer circumferential surface 21e) supported by the first bearing 5A. When the first shaft 21 rotates, the seal member 5S and the third outer peripheral surface 21f slide. By reducing the diameter of the third outer circumferential surface 21f, the sliding speed between the seal member 5S and the third outer circumferential surface 21f can be reduced, and heat generation due to sliding can be suppressed. Furthermore, by reducing the diameter of the third outer circumferential surface 21f, it is possible to reduce the torque applied to the first shaft 21 due to the dynamic friction force during sliding, thereby increasing the rotational efficiency of the first shaft 21. be able to. On the other hand, by making the outer shape of the second outer circumferential surface 21e larger than the third outer circumferential surface 21f, a sufficient thickness of the first shaft 21 can be ensured inside the second outer circumferential surface 21e. Thereby, the rigidity of the portion of the first shaft 21 supported by the first bearing 5A can be increased, and the first shaft 21 can be stably held by the first bearing 5A.

<Second supply flow path (flow path)>
The second supply channel 52 has a first channel 52a, a second channel 52e, and a third channel 52d. The second supply channel 52 is a channel that extends from the first storage section 84 through the connecting section 3 and reaches the second storage section 82 . The first flow path 52a connects the first storage section 84 and the connection space A. The second flow path 52e connects the connection space A and the inside of the recess 21a. The third flow path 52d connects the connection space A and the second storage section 82. The fluid O flows into the first flow path 52a, the second flow path 52e, and the third flow path 52d.

As shown in FIG. 2, the first flow path 52a has a hole 84a, a first groove (groove) 11a, and a second groove 11b.
The hole 84a is provided in the partition wall 65a of the housing 6. The hole 84a is formed by drilling. The upper end of the hole 84 a is connected to the first storage section 84 . The upper end of the hole 84a opens to the bottom surface of the first storage section 84. The lower end of the hole 84a is connected to the inner circumferential surface of the cylindrical portion 11. That is, the hole portion 84a penetrates the cylindrical portion 11 in the radial direction. Further, the hole 84a extends from the first storage portion 84 to the inner circumferential surface of the cylindrical portion 11.

As shown in FIG. 4, according to the present embodiment, the cylindrical portion 11 is provided with a hole 84a that extends along the radial direction and constitutes a part of the first flow path 52a. By forming a part of the first flow path 52a as the hole 84a, the fluid O can be stably supplied from the first storage section 84 to the connection space A.

In addition, in this embodiment, the case where the first flow path 52a penetrates the inside and outside of the cylindrical part 11 at the hole 84a has been described. However, the first flow path 52a may penetrate inside and outside of the cylindrical portion 11 by a notch provided in the cylindrical portion 11. That is, the cylindrical portion 11 may be provided with a notch that extends along the radial direction and constitutes a part of the first flow path 52a. Further, in this embodiment, the first flow path 52a penetrates the inside of the partition wall 65a at the hole 84a. However, the first flow path 52a may have a groove or a rib provided on the surface of the partition wall 65a instead of the hole 84a. That is, the partition wall 65a may have a groove or a rib that extends from the first storage section 84 toward the cylindrical section 11 and constitutes a part of the first flow path 52a.

The first groove 11a is provided on the inner peripheral surface of the cylindrical portion 11. The first groove 11a of this embodiment is provided on the fourth inner peripheral surface 66d of the communication hole 65h. The first groove 11a extends along the axial direction. The first groove 11a is provided over the entire length of the fourth inner peripheral surface 66d in the axial direction.

As described above, the fourth inner peripheral surface 66d surrounds the second bearing 5B from the outside in the radial direction. Therefore, the first groove 11a is covered by the outer peripheral surface of the second bearing 5B. The fluid O that reaches the first groove 11a flows through a space surrounded by the inner surface of the first groove 11a and the outer peripheral surface of the second bearing 5B.

The first groove 11a has a bottom surface 11c facing radially inward. A hole 84a is opened in the bottom surface 11c. That is, the hole 84a opens to the bottom surface 11c of the first groove 11a. When the hole 84a is opened directly into the fourth inner peripheral surface 66d, the opening of the hole 84a is covered by the outer peripheral surface of the second bearing 5B, and the fluid O is not supplied from the hole 84a to the connection space A. It's not done smoothly. According to the present embodiment, the first groove 11a is provided in the fourth inner circumferential surface 66d, and the hole 84a is opened at the bottom surface 11c of the first groove 11a, thereby allowing fluid O to flow smoothly from the opening of the hole 84a. can be supplied to

The second groove 11b is provided on the third step surface 66g, which is the inner peripheral surface of the communication hole 65h. The second groove 11b extends in the radial direction. The radially outer end of the second groove 11b is connected to the end of the first groove 11a on the other axial side (+Y side). A radially inner end of the second groove 11b is connected to the connection space A.

As described above, the third step surface 66g contacts the outer ring 5Ba of the second bearing 5B. Therefore, the second groove 11b is covered by the outer ring 5Ba of the second bearing 5B. The fluid O reaching the second groove 11b flows through a space surrounded by the inner surface of the second groove 11b and the outer ring 5Ba of the second bearing 5B.

The second channel 52e has an inflow channel 52b and an outflow channel 52c. Both the inflow channel 52b and the outflow channel 52c are channels that connect the connection space A and the third storage section B. The inflow channel 52b is a path through which the fluid O flows from the connection space A toward the third storage section B. On the other hand, the outflow channel 52c is a path through which the fluid O flows from the third storage section B toward the connection space A. Both the inflow channel 52b and the outflow channel 52c pass between the spline groove 21s and the spline protrusion 44s.

In the second channel 52e, the fluid O can flow through the inflow channel 52b and the outflow channel 52c simultaneously. When a relatively large amount of fluid O remains in the connection space A and a relatively small amount of fluid O remains in the third storage section B, more fluid O flows into the inflow channel 52b. On the other hand, when the amount of fluid O accumulated in the connection space A is relatively small and the amount of fluid O remaining in the third storage section B is relatively large, more fluid O flows through the outflow channel 52c.

According to this embodiment, the fluid O can be supplied to the connecting portion 3 by flowing through the second flow path 52e. Thereby, it is possible to suppress seizure between the spline groove 21s and the spline protrusion 44s, and to promote sliding between the spline groove 21s and the spline protrusion 44s in the axial direction. Thereby, even if an axial force is applied to the second shaft 44, this force can be suppressed from being transmitted to the first shaft 21. Furthermore, the fluid O can be filled between the spline groove 21s and the spline protrusion 44s, and the impact on the connecting portion 3 when the rotation direction of the first shaft 21 is switched can be alleviated.

According to the present embodiment, the third reservoir B is provided within the recess 21a. The fluid O remains in the third reservoir B. Therefore, when the supply of fluid O from the first storage section 84 to the connection section 3 is delayed, the fluid O in the third storage section B flows through the outflow channel 52c and reaches the connection space A. In other words, the fluid O remaining in the third reservoir B gradually travels through the gap between the spline groove 21s and the spline protrusion 44s, and can lubricate the connecting portion 3.

The first shaft 21 and the second shaft 44 of this embodiment are solid shafts. Therefore, the fluid O remaining in the third reservoir B does not flow into the first shaft 21 and the second shaft 44. Therefore, more fluid O remaining in the third reservoir B can be supplied to the connecting part 3.

The third flow path 52d is a flow path provided between the inner ring 5Bc and outer ring 5Ba of the second bearing 5B. That is, the third flow path 52d is a flow path that includes the second bearing 5B. According to this embodiment, the second bearing 5B is lubricated by the fluid O flowing through the third flow path 52d.

The connection space A of this embodiment is connected to the first storage section 84 via the first flow path 52a. The fluid O is stably supplied to the connection space A from the first storage section 84. According to this embodiment, the connection space A can stably supply the fluid O to the second flow path 52e and the third flow path 52d, and lubricate the connection portion 3 in the second flow path 52e. The second bearing 5B can be lubricated in the third flow path 52d.

As shown by the two-dot chain arrow in FIG. 4, the second supply flow path 52 includes a first flow path 152a of the modified example instead of the first flow path 52a of the embodiment, or together with the first flow path 52a. may have. The first flow path 152a of the modified example connects the first storage section 84 and the connection space A. The first flow path 152a of the modified example is, for example, a path that passes through a groove provided in the partition wall 65a and reaches the end surface of the second bearing 5B on one axial side (-Y side). Moreover, the first flow path 152a of the modified example is provided between the inner ring 5Bc and the outer ring 5Ba of the second bearing 5B. That is, the first flow path 152a is a flow path that includes the second bearing 5B. According to this embodiment, the second bearing 5B can be lubricated by the fluid O flowing through the first flow path 152a.

In this embodiment, the first storage section 84 and the second storage section 82 are both provided in the gear chamber R2. That is, the second supply flow path 52 is a flow path that flows from the gear chamber R2 into the connection space A and the third storage section B, and returns to the gear chamber R2 again. According to this embodiment, the connecting portion 3 can be lubricated without allowing the fluid O to enter the motor chamber R1. According to this embodiment, when the motor 2 is cooled by the water jacket 6D, the fluid O is not allowed to enter the motor chamber R1, so that the sealing structure of the motor chamber R1 can be simplified.

As shown by the two-dot chain arrow in FIG. 4, the second supply flow path 52 may include a third flow path 152d of a modified example. The third flow path 152d of the modified example connects the connection space A and the motor chamber R1. The third flow path 152d of the modified example can lubricate the first bearing 5A in the path. In this way, if the first storage section 84 is provided in the gear chamber and the second storage section 82 is provided in the gear chamber R2 or the motor chamber R1, the first bearing 5A is , or the second bearing 5B.

The second bearing 5B of this embodiment supports the second shaft 44 of the power transmission section 4. Therefore, vibrations caused by the meshing of the gears are more easily transmitted to the second bearing 5B than to the first bearing 5A. According to this embodiment, the operation of the second bearing 5B can be stabilized by providing the third flow path 52d between the outer ring 5Ba and the inner ring 5Bc of the second bearing 5B to lubricate the second bearing 5B. can.

In this embodiment, the first bearing 5A and the second bearing 5B are ball bearings. The first bearing 5A and the second bearing 5B have spherical rolling elements 5Ab and 5Bb, respectively. In this embodiment, the diameter of the rolling elements 5Bb of the second bearing 5B is larger than the diameter of the rolling elements 5Ab of the first bearing 5A. According to this embodiment, the strength and rigidity of the second bearing 5B, which is susceptible to vibrations from the power transmission section 4, can be increased, and the operation of the power transmission section 4 can be made smooth. Further, when helical gears are used as the first gear 41 and the second gear 42, an axial force is applied to the second bearing 5B when the power transmission section 4 is driven. The second bearing 5B can stably support the second shaft 44 against the axial force applied to the second shaft 44 by increasing the size of the rolling elements 5Bb.

Note that the first bearing 5A and the second bearing 5B may be roller bearings having cylindrical rolling elements 5Ab and 5Bb. Even in this case, the above-mentioned effect can be obtained if the diameters of the spherical or cylindrical rolling elements 5Ab and 5Bb are compared and the first bearing 5A is larger.

In this embodiment, the recess 21a is provided at the end of the first shaft 21 on one axial side (-Y side), and the protrusion 44a is provided on the end of the second shaft 44 on the other axial side (+Y side). The case where it is provided has been explained. However, among the end of the first shaft 21 on one axial side (-Y side) and the end of the second shaft 44 on the other axial side (+Y side), one has the recess 21a, and the other has the recess 21a. It is sufficient if it has a convex portion (44a).

However, it is more preferable that the recess 21a be provided on the first shaft 21 and the protrusion 44a be provided on the second shaft 44 as in this embodiment. Since the protrusion 44a and the recess 21a fit into each other, the shaft provided with the protrusion 44a has a larger diameter than the shaft provided with the recess. According to this embodiment, the second shaft 44 can be made smaller in diameter than the first shaft 21 by providing the first shaft 21 with the recess 21a and the second shaft 44 with the protrusion 44a. Therefore, even if the rolling elements 5Bb of the second bearing 5B that supports the second shaft 44 are increased in size, the outer diameter of the second bearing 5B can be prevented from becoming too large. As a result, it is possible to suppress the space in the gear chamber R2 from being compressed by the second bearing 5B.

Various embodiments and modifications of the present invention have been described above, but each configuration and combination thereof in each embodiment and modification is merely an example, and the configurations may be changed without departing from the spirit of the present invention. Additions, omissions, substitutions, and other changes are possible. Moreover, the present invention is not limited by the embodiments.

DESCRIPTION OF SYMBOLS 1... Drive device, 2... Motor, 4... Power transmission part, 5A... First bearing, 5Ab, 5Bb... Rolling element, 5B... Second bearing, 5S, 105S... Seal member, 6... Housing, 11... Cylindrical part, 11a...first groove (concave groove), 11c, 21b...bottom surface, 20...rotor, 21...first shaft, 21a...recess, 21s...spline groove, 25...fan, 30...stator, 41...gear, 44... Shaft, 44...Second shaft, 44a...Protrusion, 44b...Top surface, 44s...Spline protrusion, 52...Second supply flow path (flow path), 52a...First flow path, 52d, 152d...Third flow path , 52e... Second channel, 65a... Partition wall, 65h... Communication hole, 82... Second storage part, 84... First storage part, 84a... Hole part, 93... Third waterway (water channel), A... Connection space, B...Third reservoir, J1...Center axis, O...Fluid, R1...Motor chamber, R2...Gear chamber

Claims

a motor having a rotor having a first shaft rotating about a central axis and a stator surrounding the rotor;
a power transmission section that has a plurality of gears and a second shaft that rotates around the central axis, and that transmits the power of the motor;
a housing in which a motor chamber for accommodating the motor and a gear chamber for accommodating the power transmission section;
a first bearing that supports the first shaft;
a second bearing that supports the second shaft;
A channel through which fluid flows;
comprising a first storage section in which the fluid accumulates, and a second storage section,
An end portion on one axial side of the first shaft and an end portion on the other axial side of the second shaft,
One has a recess in which a plurality of spline grooves extending in the axial direction are provided on the inner peripheral surface,
The other has a convex portion provided with a plurality of spline protrusions extending in the axial direction on the outer peripheral surface and inserted into the concave portion,
The first shaft and the second shaft are connected to each other by engagement between the spline groove of the recess and the spline protrusion of the convex part,
The housing has a partition wall that partitions the motor chamber and the gear chamber,
The partition wall is provided with a communication hole that communicates the motor chamber and the gear chamber,
The inner peripheral surface of the communication hole holds the first bearing and the second bearing,
A connection space in which the recess opens is provided between the first bearing and the second bearing in the communication hole in the axial direction,
The flow path is
a first flow path connecting the first storage section and the connection space;
a second flow path connecting the connection space and the inside of the recess;
a third flow path connecting the connection space and the second storage section;
A drive device in which the fluid flows through the first flow path, the second flow path, and the third flow path.
The first storage section is provided in the gear chamber,
The drive device according to claim 1, wherein the second storage section is provided in the gear chamber or the motor chamber.
The drive device according to claim 1 or 2, wherein a third storage portion in which the fluid remains is provided between the bottom surface of the recess and the tip surface of the convex portion.
The recess is provided at one end of the first shaft in the axial direction,
The drive device according to any one of claims 1 to 3, wherein the convex portion is provided at the other end of the second shaft in the axial direction.
The diameter of the rolling elements of the second bearing is larger than the diameter of the rolling elements of the first bearing.
The drive device according to claim 4.
The drive device according to any one of claims 1 to 5, wherein the first storage section and the second storage section are provided in the gear chamber.
The drive device according to claim 6, wherein the communication hole is provided with a seal member that seals a gap between the inner peripheral surface of the communication hole and the outer peripheral surface of the first shaft.
The sealing member is located between the first bearing and the second bearing,
The drive device according to claim 7, wherein the connection space is provided between the seal member and the second bearing.
The drive device according to claim 7, wherein the seal member is arranged on the other axial side of the first bearing and the second bearing.
The sealing member is held on the inner circumferential surface of the communication hole and contacts the outer circumferential surface of the first shaft,
The drive device according to any one of claims 7 to 9, wherein the first shaft has an outer diameter of a portion that contacts the seal member and is smaller than an outer diameter of a portion that is supported by the first bearing.
The partition wall has a cylindrical portion that protrudes toward the gear chamber along an inner edge of the communication hole and surrounds and holds the second bearing,
The drive device according to any one of claims 1 to 10, wherein the cylindrical portion is provided with a hole extending along the radial direction and forming a part of the first flow path.
A concave groove extending along the axial direction is provided on the inner circumferential surface of the cylindrical portion,
The drive device according to claim 11, wherein the hole opens at a bottom surface of the groove.
The drive device according to any one of claims 1 to 12, wherein the first storage portion is a catch tank that is disposed within the gear chamber and opens upward.
The drive device according to any one of claims 1 to 13, wherein the housing is provided with a water channel extending along the outer peripheral surface of the stator.
The drive device according to any one of claims 1 to 14, wherein a fan that circulates air within the motor chamber is fixed to the rotor.