Power transmission device, motor unit, and vehicle

Abstract

The present invention provides a power transmission device, a motor unit, and a vehicle. The gear portion of the power transmission device is connected to an axial side of a first shaft that can rotate around a first axis extending in a horizontal direction. The first shaft is supported by a first bearing. The gear portion has a second shaft that can rotate around a second axis that is arranged below the first axis. Lubricating fluid is provided to a first bearing retaining portion of the first bearing. A gear housing that accommodates the gear portion has an oil passage that is arranged below the first bearing. One end of the oil passage is connected to the first bearing retaining portion via the first bearing. The other end of the oil passage is connected to the second bearing retaining portion of the second bearing that supports the second shaft via an opening that is arranged below the first bearing.

Description

Technical Field

[0001] The present invention relates to a power transmission device, a motor unit, and a vehicle. Background Art

[0002] Conventionally, a drive device is known in which oil stirred up by the rotation of a differential gear is supplied to a bearing that rotatably supports an input shaft to which a driving force from an electric motor is input (see Japanese Patent Application Laid-Open No. 2019-152236).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-152236

[0004] However, when oil is pumped up by gears, it may be difficult to supply oil to bearings disposed deep within a reduction gear or the like that transmits torque from an input shaft to a differential gear. Summary of the Invention

[0005] The object of the present invention is to effectively lubricate bearings.

[0006] An exemplary power transmission device of the present invention includes a gear portion and a gear housing. The gear portion is connected to one axial side of a first shaft that is rotatable about a first axis extending horizontally. The gear housing accommodates the gear portion. The gear portion includes a first bearing, a second shaft, and a second bearing. The first bearing supports the first shaft so that it can rotate. The second shaft is rotatable about the second axis. The second bearing supports the second shaft so that it can rotate. The second axis is parallel to the first axis and is positioned below the first axis. The gear housing includes a first bearing retaining portion, a second bearing retaining portion, and a first passage. The first bearing retaining portion retains the first bearing. The second bearing retaining portion retains the second bearing. The first passage is positioned below the first bearing. The first bearing retaining portion and the second bearing retaining portion are cylindrical and extend in the axial direction. Lubricating fluid is supplied to the first bearing retaining portion. The second bearing holding portion has an opening extending radially with respect to the second axis, the opening being positioned below the first bearing. One end of the first passage is connected to the first bearing holding portion via the first bearing. The other end of the first passage is connected to the second bearing holding portion via the opening.

[0007] An exemplary motor unit of the present invention includes the above-described power transmission device and a motor as a drive source.

[0008] An exemplary vehicle of the present invention includes the above-described motor unit.

[0009] According to the exemplary power transmission device, motor unit, and vehicle of the present invention, it is possible to effectively lubricate the bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a conceptual diagram of a motor unit according to one embodiment.

[0011] Figure 2 This is a cross-sectional view of the output shaft.

[0012] Figure 3 This is a diagram viewed from the axial direction with the cover of the gear housing removed.

[0013] Figure 4 This is a diagram of the side plate portion of the gear housing as viewed from the axial direction.

[0014] Figure 5 This is an enlarged perspective view of the tray portion.

[0015] Figure 6 This is an enlarged side view of the tray.

[0016] Figure 7 This is an enlarged perspective view of the recess and the differential case.

[0017] Figure 8 This is a three-dimensional diagram of an enlarged groove portion.

[0018] Figure 9 This is a side view of the inner side of the cover.

[0019] Figure 10 It is a perspective view of the supply limiting component.

[0020] Figure 11 This is a schematic diagram showing an example of a vehicle including a motor unit.

[0021] Label Description

[0022] 1: Motor unit; 2: Motor; 3: Power transmission device; 5: Motor housing; 6: Gear housing; 7: Coolant circulation unit; 21: Rotor; 22: Power shaft; 23: Rotor core; 24: Rotor magnet; 25: Stator; 26: Stator core; 27: Coil; 30: Gear unit; 31: Speed ​​reduction device; 32: Output shaft; 33: Differential gear; 34: Bearing; 41: 1st bearing; 42: 2nd bearing; 43: 3rd bearing; 44: 4th bearing; 51: Motor housing body; 52: Bearing holder; 60: Inner Internal space; 60U: Upper surface; 61: Side plate; 62: Cover; 63: Tray; 64: Recess; 65: Groove; 71: Piping; 72: Pump; 73: Oil cooler; 74: Motor oil reservoir; 150: Battery; 200: Vehicle; 220: Inlet; 221: Hollow portion; 271: Coil end; 311: Main drive gear; 312: Intermediate driven gear; 313: Final drive gear; 314: Intermediate shaft; 315: First intermediate bearing; 316: Second intermediate bearing; 321: Output shaft body; 3 31: First gear; 332: Housing; 333: Pinion; 334: Pinion shaft; 335: Side gear; 341: Bearing; 341: First output bearing; 342: Second output bearing; 50: Motor housing; 611: First through-hole; 612: First intermediate bearing retaining portion; 621: Cover cylinder; 622: Cover bottom; 623: Cover bearing retaining portion; 624: Second intermediate bearing retaining portion; 625: Second output bearing mounting portion; 626: Second output shaft through-hole; 627, 628: Oil passage; 629 : Supply limiting component; 631: Opposing surface; 632: Protrusion; 633: Corner; 641: Cylindrical portion; 642: Bottom; 643: First output shaft through-hole; 644: First bearing mounting portion; 651: Peripheral opening; 652: Shaft opening; 653: Inner peripheral surface; 654: Upper edge; 655: Lower edge; 656: Guide; 6241: Opening; 6281: Inclined surface; 6282: Wall; 6291: Annular portion; 6292: Protrusion; 6293: Through-hole; CL: Lubricating fluid. DETAILED DESCRIPTION

[0023] Hereinafter, a motor unit according to an embodiment of the present invention will be described with reference to the drawings.

[0024] In this specification, the direction parallel to the rotation axis J2 of the motor 2 is referred to as the "axial direction" of the motor unit 1. Figure 1As shown, the power transmission device 3 side is referred to as one axial direction N, and the motor 2 side is referred to as the other axial direction T. Furthermore, the radial direction perpendicular to the specified axis is simply referred to as the "radial direction," and the circumferential direction centered on the specified axis is simply referred to as the "circumferential direction." Furthermore, in this specification, "parallel directions" include not only completely parallel directions but also approximately parallel directions. Furthermore, "extending in a specified direction or plane" includes not only extending strictly in the specified direction but also extending in a direction inclined by less than 45° relative to the specified direction.

[0025] Motor unit 1

[0026] Hereinafter, a motor unit 1 according to an exemplary embodiment of the present invention will be described with reference to the drawings. Figure 1 This is a conceptual diagram of a motor unit 1 according to one embodiment. Figure 1 This is only a conceptual diagram, and the arrangement and dimensions of each component are not necessarily the same as those of the actual motor unit 1 .

[0027] The motor unit 1 is mounted on a vehicle having at least a motor as a power source, such as a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV). The motor unit 1 is used as a power source for the above-mentioned vehicles. Figure 11 1 is a schematic diagram showing an example of a vehicle 200 having a motor unit 1. Figure 11 A vehicle 200 is conceptually illustrated. Vehicle 200 includes a motor unit 1 and a battery 150. Battery 150 stores electric power to be supplied to motor unit 1. In the example of vehicle 200, motor unit 1 drives the left and right front wheels. However, motor unit 1 only needs to drive at least one wheel.

[0028] like Figure 1 As shown, the motor unit 1 includes a motor 2 as a driving source and a power transmission device 3 for transmitting the power of the motor 2. Figure 1 As shown, the motor 2 includes a rotor 21 that rotates about a rotation axis J2 extending in the horizontal direction, and a stator 25 located radially outside the rotor 21 .

[0029] Motor 2

[0030] The motor 2 is a brushless DC motor. The motor 2 is driven by electric power from an inverter (not shown). The motor 2 is an inner rotor type motor in which a rotor 21 is rotatably arranged inside a stator 25 .

[0031] Rotor 21

[0032] The rotor 21 is rotated by receiving power from the stator 25. Figure 1As shown, the rotor 21 includes a power shaft 22, a rotor core 23, and a rotor magnet 24. The rotor 21 rotates around a rotation axis J2 extending in the horizontal direction.

[0033] The power shaft 22 rotates about the rotation axis J2. The power shaft 22 has a hollow portion 221 extending along the rotation axis J2. Specifically, the power shaft 22 has a cylindrical shape extending in the axial direction. The power shaft 22 has an inlet 220 on one axial side N for allowing lubricating fluid CL to flow into the hollow portion 221. The inlet 220 is connected to an oil passage 627 of the cover portion 62, described later.

[0034] The power shaft 22 is rotatably supported by the motor housing 5 and the gear housing 6 via a first bearing 41 , a second bearing 42 , a third bearing 43 , and a fourth bearing 44 , which will be described later.

[0035] In addition, the power shaft 22 can also be divided in the middle part in the axial direction. When the power shaft 22 can be divided, the divided power shaft 22 can adopt, for example, a threaded coupling using external threads and internal threads. In addition, it can also be joined by fixing methods such as pressing in and welding. When using fixing methods such as pressing in and welding, it is also possible to use serrations obtained by combining concave and convex parts extending in the axial direction. By adopting such a structure, rotation can be transmitted reliably. In addition, the power shaft 22 can also be formed as a single component.

[0036] The rotor core 23 is formed, for example, by laminating thin electromagnetic steel sheets. The rotor core 23 is a cylindrical body extending in the axial direction. A plurality of rotor magnets 24 are fixed to the rotor core 23. The plurality of rotor magnets 24 are arranged circumferentially with alternating magnetic poles.

[0037] <Stator 25>

[0038] like Figure 1 As shown, the stator 25 includes a stator core 26, a coil 27, and an insulator (not shown) interposed between the stator core 26 and the coil 27. The stator 25 is held by the motor housing 5. The stator core 26 includes a plurality of magnetic pole teeth (not shown) extending radially inward from the inner circumference of an annular yoke.

[0039] The coil 27 is formed by winding a conductive wire around the magnetic pole teeth. The coil 27 has a coil end portion 271 protruding from an axial end surface of the stator core 26 .

[0040] <Motors and others>

[0041] A resolver (not shown) is mounted on the end portion on the other axial side T of the power shaft 22. The resolver detects the position of the rotor 21, that is, the rotation angle. Furthermore, a bus bar (not shown) is disposed on the end portion on the other axial side T inside the motor housing 5. The bus bar connects the inverter unit (not shown) to the coil 27 and supplies power to the coil 27.

[0042] Motor housing 5

[0043] like Figure 1 As shown, the motor 2 is housed within a motor housing 5. The motor housing 5 includes a motor housing body 51 and a bearing holder 52. The motor housing body 51 and the bearing holder 52 are formed of, for example, a conductive material such as iron, aluminum, or alloys thereof, in other words, metal, but are not limited to these materials. Furthermore, the motor housing body 51 and the bearing holder 52 may be formed of the same material or different materials. To prevent galvanic corrosion at the contacting portions, they are preferably formed of the same material.

[0044] <Motor housing body 51>

[0045] The motor housing body 51 is cylindrical. The end portion of the motor housing body 51 on one axial side N is covered by a side plate 61 of the gear housing 6 (described later). The stator core 26 is fixed inside the motor housing body 51. Furthermore, in the motor unit 1 of this embodiment, the motor housing body 51 and the side plate 61 are formed from a single component. By forming the motor housing body 51 and the side plate 61 from a single component, the rigidity of the motor housing 5 can be improved.

[0046] Bearing retainer 52

[0047] The bearing holder 52 is fixed to the other axial side T of the motor housing body 51. The end of the motor housing body 51 on the other axial side T is covered by the bearing holder 52. The bearing holder 52 can be fixed to the motor housing body 51 by screws, for example, but is not limited to this method. A wide variety of methods can be used to securely fix the bearing holder 52 to the motor housing body 51, such as screwing or press-fitting.

[0048] As a result, the motor housing body 51 and the bearing holder 52 are in close contact. Here, close contact means that the lubricating fluid CL inside the components does not leak to the outside and foreign matter such as water, dust, and dirt from the outside does not enter. Regarding close contact, the same structure is used below.

[0049] The third bearing 43 is mounted on the bearing holder 52 to rotatably hold the end portion of the power shaft 22 on the other axial side T. In other words, the end portion of the power shaft 22 on the other axial side T is rotatably supported by the motor housing 5 via the third bearing 43.

[0050] Power Transmission Device 3

[0051] The details of the power transmission device 3 will be described with reference to the accompanying drawings. In the motor unit 1, the power transmission device 3 transmits the power of the motor 2 to a shaft (not shown) arranged outside the motor unit 1. For example, when the motor unit 1 is used to drive a vehicle, the external shaft is the drive shaft of the vehicle. Figure 1 As shown, the power transmission device 3 includes a gear portion 30 and a gear housing 6 that accommodates the gear portion 30 .

[0052] The gear unit 30 includes a speed reduction device 31 and an output shaft 32. Figure 1 As shown, the reduction gear 31 is connected to the power shaft 22. The reduction gear 31 has a function of reducing the rotational speed of the motor 2 and increasing the torque output from the motor 2 in accordance with the reduction ratio. The reduction gear 31 transmits the torque output from the motor 2 to the output shaft 32. That is, the gear portion 30 is connected to the axial side N of the power shaft 22 that rotates around the rotation axis J2 extending in the horizontal direction. In addition, the rotation axis J2 is an example of the "first axis" of the present invention. The power shaft 22 is an example of the "first axis" of the present invention.

[0053] <Reduction gear 31>

[0054] The reduction gear 31 includes a main drive gear 311, a counter driven gear 312, a final drive gear 313, and an intermediate shaft 314. In other words, the gear unit 30 includes the main drive gear 311, the counter driven gear 312, the final drive gear 313, and the intermediate shaft 314. The main drive gear 311 is an example of a "second gear" in the present invention. The counter driven gear 312 is an example of a "third gear" in the present invention. The final drive gear 313 is an example of a "fourth gear" in the present invention. The intermediate shaft 314 is an example of a "second shaft" in the present invention. The torque output from the motor 2 is transmitted to the first gear 331 of the output shaft 32 via the power shaft 22, the main drive gear 311, the counter driven gear 312, the intermediate shaft 314, and the final drive gear 313. The gear ratios and number of gears can be varied to suit the desired reduction ratio. The reduction gear 31 is a parallel-axis gear type reducer, in which the axes of the gears are arranged parallel to each other.

[0055] The main drive gear 311 is disposed on the outer peripheral surface of the power shaft 22. The main drive gear 311 may be the same component as the power shaft 22, or may be a separate component that is securely fixed thereto. The main drive gear 311 rotates together with the power shaft 22 about the rotation axis J2.

[0056] The intermediate shaft 314 extends along an intermediate axis J4, which is parallel to the rotation axis J2. Both ends of the intermediate shaft 314 are rotatably supported by the gear housing 6 via a first intermediate bearing 315 and a second intermediate bearing 316 about the intermediate axis J4. In other words, the gear unit 30 includes the first intermediate bearing 315 and the second intermediate bearing 316. The intermediate shaft 314 is rotatable about the intermediate axis J4. The first intermediate bearing 315 and the second intermediate bearing 316 rotatably support the intermediate shaft 314. The intermediate axis J4 is parallel to the rotation axis J2 and positioned below the rotation axis J2. Furthermore, the intermediate axis J4 is positioned to one side of the rotation axis J2 in a direction perpendicular to the axial direction and the vertical direction. In this embodiment, it is positioned to the differential axis J5 side of the rotation axis J2 in a direction perpendicular to the axial direction and the vertical direction. The intermediate axis J4 is an example of a "second axis" in the present invention. The second intermediate bearing 316 is an example of a "second bearing" in the present invention. The intermediate driven gear 312 and the final drive gear 313 are arranged on the outer circumference of the intermediate shaft 314. The intermediate driven gear 312 may be the same component as the intermediate shaft 314, or may be a separate component and securely fixed thereto. The final drive gear 313 is also the same as the intermediate driven gear 312.

[0057] The intermediate driven gear 312 and the final drive gear 313 rotate integrally with the intermediate shaft 314 about the intermediate axis J4. The intermediate driven gear 312 meshes with the main drive gear 311. The final drive gear 313 meshes with the first gear 331 of the output shaft 32.

[0058] The torque of the power shaft 22 is transmitted from the main drive gear 311 to the counter driven gear 312. The torque transmitted to the counter driven gear 312 is then transmitted to the final drive gear 313 via the intermediate shaft 314. The torque is then transmitted from the final drive gear 313 to the output shaft 32.

[0059] Output shaft 32

[0060] Figure 2 is a cross-sectional view of the output shaft 32. Figure 1 、 Figure 2As shown, the output shaft 32 includes a shaft body 321 and a differential device 33, which are arranged on one axial side N and the other axial side T. That is, the output shaft 32 includes a differential device 33. The shaft body 321 is cylindrical, and the center of the shaft body 321 is consistent with the differential axis J5 parallel to the rotation axis J2. The shaft body 321 rotates around the differential axis J5 by the torque transmitted from the reduction gear 31. In addition, in the case of a structure in which the shaft body 321 does not generate a rotation difference, the differential device 33 can also be omitted. In this case, there is one output shaft 32, and the first gear 331 described later can also be directly fixed to the output shaft 32. In addition, in the following description, the output shaft body 321 is sometimes referred to as the output shaft body 321N on the one axial side N and the output shaft body 321T on the other axial side T, as needed.

[0061] Differential gear 33

[0062] like Figure 2 As shown, the differential device 33 includes a first gear 331, a housing 332, a pair of pinion gears 333, a pinion shaft 334, and a pair of side gears 335. Specifically, the gear unit 30 includes the first gear 331 mounted on the output shaft 32. The pair of pinion gears 333, the pinion shaft 334, and the pair of side gears 335 are disposed within the housing 332.

[0063] The first gear 331 is the ring gear of the differential device 33. The first gear 331 is fixed to the outer surface of the housing 332 by screw fastening. The first gear 331 meshes with the final drive gear 313. The first gear 331 and the housing 332 are rotatable about the differential axis J5, which is parallel to the rotation axis J2. The housing 332 of the differential device 33 is disposed in the recess 64 of the gear housing 6, which will be described later. The housing 332 is rotatably supported by the gear housing 6 by a first output bearing 341 and a second output bearing 342, details of which will be described later.

[0064] The fixing of the first gear 331 to the housing 332 is not limited to screw fastening, and a wide range of methods such as press-fitting, welding, and welding can be used to firmly fix the first gear 331 to the housing 332. The lower end of the first gear 331 is arranged inside the lubricating fluid CL such as lubricating oil stored in the lower part of the gear housing 6 (see Figure 1 ). Therefore, when the first gear 331 rotates, the lubricating liquid CL is lifted up by the gear teeth of the first gear 331. The lubricating liquid CL lifted up by the first gear 331 lubricates or cools the gears and bearings of the gear unit 30. The lifted lubricating liquid CL is stored in the tray portion 63, described later, and is also used to cool the motor 2 via the power shaft 22. Details of lubrication and cooling using the lubricating liquid CL will be described later.

[0065] A pinion shaft 334 extends from the inner surface of the housing 332 in a direction perpendicular to the differential axis J5. Both ends of the pinion shaft 334 are fixed to the inner surface of the housing 332. A pair of rotatable pinion gears 333 are bevel gears. The pair of pinion gears 333 are independently rotatable about the pinion shaft 334.

[0066] Each output shaft body 321 is inserted into the housing 332 from both ends of the housing 332 in the direction along the differential axis J5. The output shaft body 321 is arranged to rotate independently of the housing 332. A pair of side gears 335 are fixed to the portion of each output shaft body 321 that is inserted into the housing 332. The pair of side gears 335 are bevel gears and mesh with the pair of pinion gears 333.

[0067] In the differential device 33, when there is no rotational difference between the output shaft bodies 321, the pair of pinion gears 333, while their rotation about the pinion shaft 334 is stopped, rotate along with the housing 332 about the differential axis J5. Torque is then transmitted from the housing 332 to the pair of side gears 335 meshing with the pair of pinion gears 333. This causes the output shaft bodies 321 to rotate in the same direction and at the same speed. The same amount of torque is transmitted to each output shaft body 321.

[0068] On the other hand, when there is a rotational difference in the output shaft body 321, the pair of pinion gears 333 rotate about the pinion shaft 334 along with the housing 332 about the differential axis J5, thereby absorbing the rotational difference of the pair of side gears 335. Torque is then transmitted from the housing 332 to the pair of side gears 335 meshing with the pair of pinion gears 333. In this manner, the same torque is transmitted to each output shaft body 321 while absorbing the rotational difference.

[0069] The output shaft body 321 protrudes to the outside of the gear housing 6. A drive shaft (not shown) connected to, for example, a drive wheel of a vehicle is connected to the output shaft body 321.

[0070] <Gear housing 6>

[0071] The gear housing 6 will be described with reference to the drawings. Figure 3 This is a diagram viewed from the axial direction in a state where the cover portion 62 of the gear housing 6 is removed. Figure 4 This is a diagram of the side plate portion 61 of the gear housing 6 as viewed from the axial direction. Figure 5 It is an enlarged perspective view of the tray portion 63 . Figure 6 It is an enlarged side view of the tray portion 63 . Figure 7 It is an enlarged perspective view of the recessed portion 64 and the housing 332 of the differential device 33 . Figure 8 It is an enlarged perspective view of the groove portion 65 . Figure 9 It is a side view of the inner side of the cover portion 62 .

[0072] like Figure 1 As shown, lubricating fluid CL is stored in the internal space 60 of the gear housing 6. Furthermore, the gear portion 30 is housed in the internal space 60 of the gear housing 6. That is, the gear portion 30 is housed in the gear housing 6, and lubricating fluid CL is stored therein.

[0073] The gear housing 6 has a side plate portion 61 (see Figure 3 、 Figure 4 etc.), cover 62, tray 63 (see Figure 1 、 Figure 5 、 Figure 6 etc.), recess 64 (refer to Figure 2 、 Figure 7 、 Figure 8 etc.), groove portion 65 (see Figure 7 、 Figure 8 The side plate portion 61 and the cover portion 62 are formed of, for example, a conductive material such as iron, aluminum, or an alloy thereof, in other words, a metal, but are not limited to these materials. Furthermore, the side plate portion 61 and the cover portion 62 may be formed of the same material or different materials. To prevent contact corrosion between dissimilar metals at the contact portion, they are preferably formed of the same material. Furthermore, as described above, the side plate portion 61 is formed of the same component as the motor housing body 51 of the motor housing 5.

[0074] <Side plate 61>

[0075] like Figure 1 、 Figure 4 As shown, the side plate portion 61 covers the other axial side T of the gear housing 6. The side plate portion 61 extends in a direction intersecting the rotation axis J2. Specifically, the side plate portion 61 extends in a direction perpendicular to the rotation axis J2. A first through-hole 611 is formed in the side plate portion 61. In other words, the gear housing 6 includes a side plate portion 61 disposed at the end portion on the other axial side T and extending in a direction intersecting the axial direction.

[0076] The first through-hole 611 extends axially, with its center coinciding with the rotation axis J2. The power shaft 22 is disposed so as to pass through the first through-hole 611. The power shaft 22 is rotatably supported on the side plate portion 61 via the second bearing 42 and the fourth bearing 44. The second bearing 42 is disposed on one axial side N of the side plate portion 61, and the fourth bearing 44 is disposed on the other axial side T of the side plate portion 61. Thus, the power shaft 22 is rotatably supported at its intermediate portion in the axial direction, thereby suppressing vibration, deflection, and the like of the power shaft 22 when the power shaft 22 rotates.

[0077] like Figure 1 、 Figure 4As shown, the side plate portion 61 includes a first intermediate bearing holding portion 612. The first intermediate bearing holding portion 612 is cylindrical in shape with its center overlapping the intermediate axis J4. The first intermediate bearing 315 is mounted on the first intermediate bearing holding portion 612.

[0078] <Recessed portion 64>

[0079] The recess 64 is formed from the same component as the side plate 61. The recess 64 is cylindrical and extends from the surface of the side plate 61 on the other axial side T toward the other axial side T. The recess 64 includes a cylindrical portion 641 and a bottom portion 642. Furthermore, the recess 64 is open on the one axial side N. In other words, the recess 64 is connected to the interior of the gear housing 6. In other words, the gear housing 6 includes a cylindrical recess 64 that is recessed from the side plate 61 toward the other axial side T and is open on the one axial side N.

[0080] The center of the cylinder 641 is aligned with the differential axis J5. The bottom 642 is in the shape of a flat plate extending from the end portion on the other axial side T of the cylinder 641 toward the inner side of the cylinder 641. The bottom 642 has a first output shaft through-hole 643 and a first bearing mounting portion 644 on which the first output bearing 341 is mounted. The first output shaft through-hole 643 penetrates in the axial direction. The output shaft body 321T on the other axial side T passes through the first output shaft through-hole 643 (see Figure 1 、 Figure 2 An oil seal (not shown) is provided between the right output shaft 32 and the first output shaft through-hole 643 to prevent leakage of the lubricating fluid CL. The first output bearing 341 rotatably supports the housing 332 of the differential device 33. Specifically, the gear unit 30 includes the bearing 341 disposed at the end portion of the recess 64 on the other axial side T.

[0081] <Groove 65>

[0082] The groove portion 65 is formed on the surface of the axial side N of the side plate portion 61. Figure 4 、 Figure 7 As shown, the groove portion 65 has a circumferential opening portion 651, an axial opening portion 652, and an inner peripheral surface 653. The circumferential opening portion 651 opens on the inner peripheral surface of the recess 64. In addition, the axial opening portion 652 faces the internal space 60 of the gear housing 6 and opens on the surface of the axial side N of the side plate portion 61. That is, the groove portion 65 has a circumferential opening portion 651 that opens on the inner peripheral surface of the recess 64 and an axial opening portion 652 that opens on the surface of the axial side N of the side plate portion 61. Moreover, the circumferential opening portion 651 is radially opposed to the housing 332 (refer to Figure 2 That is, a portion of the outer side surface of the housing 332 faces the groove portion 65. In addition, the end edge of the peripheral opening portion 651 on the axial side N is continuous with the end edge of the shaft opening portion 652 on the housing 332 side.

[0083] like Figure 2As shown, the groove portion 65 extends axially from the surface of the axial side N of the side plate portion 61 to the first bearing mounting portion 644. In addition, one end of the shaft opening portion 652 of the groove portion 65 reaches the outer surface (opposing surface 631) of the tray portion 63 described later. The groove portion 65 is inclined downward from the tray portion 63 toward the peripheral opening portion 651. That is, the groove portion 65 is inclined downward toward the peripheral opening portion 651 and the end portion on the other axial side T reaches the bearing 34. Moreover, the interior of the groove portion 65 is inclined downward toward the peripheral opening portion 651. In more detail, the groove portion 65, in particular the peripheral opening portion 651 of the groove portion 65, extends axially along the housing 332 of the differential device 33.

[0084] Furthermore, the inner circumferential surface 653 extending from one end of the shaft opening 652, facing the circumferential opening 651, approaches the first bearing mounting portion 644 as it moves toward the other axial side T. Specifically, the inner circumferential surface 653 of the groove 65, facing the circumferential opening 651, approaches the bearing 34 as it moves toward the other axial side T. This configuration allows the lubricating fluid CL, which is lifted by the first gear 331 and strikes the facing surface 631 of the tray portion 63, which faces the first gear 331, to be stably supplied to the first output bearing 341. This allows for efficient lubrication and cooling of the first output bearing 341.

[0085] The shaft opening 652 connects the inner periphery of the recess 64 and the tray portion 63. That is, the shaft opening 652 of the groove portion 65 reaches the opposing surface 631. Figure 7 、 Figure 8 As shown, the shaft opening 652 has an upper edge 654 and a lower edge 655. The upper edge 654 of the shaft opening 652 of the groove 65 faces upward as it approaches the axial side N. Furthermore, a guide portion 656 is provided that extends from the lower edge 655 of the shaft opening 652 toward the axial side N.

[0086] <Cover 62>

[0087] The cover portion 62 is mounted on one axial side N of the side plate portion 61. Figure 1 、 Figure 9 As shown, the cover portion 62 is cylindrical with a bottom, and includes a cover cylinder portion 621 and a cover bottom portion 622. The cover bottom portion 622 extends radially inward from the end portion on one axial side N of the cover cylinder portion 621. The end portion on the other axial side T of the cover cylinder portion 621 is open and tightly fixed to the side plate portion 61. In other words, the gear housing 6 includes a cover portion 62 that covers the axial side N of the side plate portion 61.

[0088] That is, the area enclosed by the side panels 61 and the cover 62 constitutes the internal space 60 of the gear housing 6. The cover 62 is secured to the side panels 61 by screws, but this is not limited to this method; press-fitting, welding, or the like may also be employed. However, the cover 62 is preferably removable relative to the side panels 61 for maintenance of the gear unit 30 disposed therein.

[0089] The cover bottom portion 622 includes a cover bearing retaining portion 623, a second intermediate bearing retaining portion 624, a second output bearing mounting portion 625, a second output shaft through-hole 626, oil passages 627 and 628, and a supply restriction member 629. In other words, the gear housing 6 includes the cover bearing retaining portion 623, the second intermediate bearing retaining portion 624, the second output bearing mounting portion 625, the second output shaft through-hole 626, oil passages 627 and 628, and a supply restriction member 629. The cover bearing retaining portion 623 and the second intermediate bearing retaining portion 624 are cylindrical, extending in the axial direction, and protrude from the surface of the cover bottom portion 622 on the other axial side T toward the other axial side T. The cover bearing retaining portion 623 is an example of the "first bearing retaining portion" of the present invention. The second intermediate bearing retaining portion 624 is an example of the "second bearing retaining portion" of the present invention. The cover bearing retaining portion 623 retains the first bearing 41. The first bearing 41 retains the end portion on the axial side N of the power shaft 22. In other words, the first bearing 41 supports the power shaft 22 so that it can rotate. In addition, the gear portion 30 has the first bearing 41. In addition, the first bearing 41 is an example of the "first bearing" of the present invention. In this embodiment, the first bearing 41 adopts a rolling bearing such as a ball bearing. Thus, the portion of the power shaft 22 arranged inside the gear housing 6 is rotatably supported by the gear housing 6 via the first bearing 41 and the second bearing 42. As will be described later, the cover bearing retaining portion 623 is supplied with lubricating liquid CL.

[0090] The second intermediate bearing retaining portion 624 also retains the second intermediate bearing 316. The second intermediate bearing 316 retains the axial end portion N of the intermediate shaft 314. Thus, the intermediate shaft 314 is rotatably mounted on the gear housing 6 at both ends thereof via the first intermediate bearing 315 and the second intermediate bearing 316. The second intermediate bearing retaining portion 624 has an opening 6241. The opening 6241 extends radially through the second intermediate bearing retaining portion 624 relative to the intermediate axis J4. The opening 6241 is positioned below the first bearing 41.

[0091] The center of the second output shaft through-hole 626 is aligned with the differential axis J5, and the output shaft body 321N on the axial side N passes through it. An oil seal (not shown) is disposed in the gap between the output shaft body 321N on the axial side N and the second output shaft through-hole 626. Furthermore, the second output bearing mounting portion 625 is disposed radially outward of the second output shaft through-hole 626. The second output bearing mounting portion 625 is cylindrical, with its center aligned with the differential axis J5.

[0092] Furthermore, a second output bearing 342 is mounted on the second output bearing mounting portion 625. The second output bearing 342 holds the housing 332 of the differential device 33. Thus, the differential device housing 332 is rotatably supported by the gear housing 6 via the first output bearing 341 and the second output bearing 342. Specifically, the gear unit 30 includes an output shaft 32 that extends along the rotation axis J2 and is rotatably supported by the gear housing 6 via the bearings 341 and 342.

[0093] The oil circuit 627 is a groove formed on the other axial side T of the cover bottom 622. As described above, the gear housing 6 has the oil circuit 627. The oil circuit 627 is a passage for the lubricating fluid CL connecting the end of the axial side N of the tray portion 63 and the cover bearing retaining portion 623. In addition, the oil circuit 627 is an example of the "second passage" of the present invention. One end of the oil circuit 627 extends to the central portion of the cover bearing retaining portion 623. In addition, the other end of the oil circuit 627 is connected to the end of the axial side N of the tray portion 63. That is, the cover portion 62 has an oil circuit 627 connected to the tray portion 63. The lubricating fluid CL stored in the tray portion 63 is provided to the oil circuit 627. As Figure 1 As shown, part of the lubricating fluid CL supplied to the oil passage 627 is supplied to the first bearing 41 and then flows into the oil passage 628. The other part of the lubricating fluid CL supplied to the oil passage 627 flows into the hollow portion 221 from the inlet 220 on the axial side N of the power shaft 22.

[0094] <Tray section 63>

[0095] The lubricating fluid CL lifted by the first gear 331 is stored in the tray portion 63. Figure 3 、 Figure 5 、 Figure 6 As shown in FIG. 1 , the tray portion 63 is disposed above the intermediate driven gear 312. The bottom of the tray portion 63 is disposed along the outer periphery of the intermediate driven gear 312. With this configuration, the tray portion 63 can be disposed at a lower position, thereby enabling the motor housing 5 to be kept lower.

[0096] The tray portion 63 is arranged at a position radially outward of the first gear 331 with respect to the differential axis J5. Figure 4 、 Figure 9As shown, the upper portion of the tray portion 63 is open. As described above, the gear housing 6 includes the tray portion 63. The tray portion 63 extends from the side plate portion 61 toward the axial side N. The end portion of the tray portion 63 on the axial side N is connected to the cover bottom portion 622. In other words, the end portion of the tray portion 63 on the axial side N is connected to the cover portion 62.

[0097] The tray portion 63 has a facing surface 631. The facing surface 631 faces the gear teeth of the first gear 331. The facing surface 631 may face the gear teeth of the first gear 331 in its entirety or in part. That is, the tray portion 63 has the facing surface 631 that faces at least the outer peripheral surface of the first gear 331 in the radial direction.

[0098] The facing surface 631 extends upward in a direction that moves away from the gear teeth of the first gear 331 as it moves upward. In other words, the facing surface 631 moves away from a circumferential tangent line to the first gear 331 at the point where a line connecting the center of the first gear 331 and the lower end of the facing surface 631 intersects the outer circumferential surface of the first gear 331 as it moves upward.

[0099] like Figure 4 As shown, the tray portion 63 has a protrusion 632. The protrusion 632 protrudes from the upper end of the facing surface 631. Furthermore, the protrusion 632 faces the first gear 331 in a radial direction relative to the differential axis J5. Specifically, the tray portion 63 has the protrusion 632 extending from the upper end of the facing surface 631 in a direction approaching the outer circumference of the first gear 331. Specifically, the protrusion 632 extends from the upper end of the tray portion 633 on the first gear 331 side in a direction perpendicular to the axial direction, in a direction approaching the outer circumference of the first gear 331. This allows lubricating fluid CL stored in the lower portion of the gear housing 6 to be supplied to the cover bearing retaining portion 623. For example, the lubricating fluid CL stored in the lower portion of the gear housing 6 is lifted from the lower portion of the gear housing 6 by the rotation of the first gear 331, accumulated in the tray portion 63 via the upper surface of the protrusion 632, and supplied to the cover bearing retaining portion 623 through the oil passage 627.

[0100] The protrusion 632 extends along the upper surface 60U of the internal space 60 of the gear housing 6 . Specifically, at the distal end of the protrusion 632 , the gap with the upper surface 60U of the internal space 60 of the gear housing 6 is larger than the gap with the first gear 331 .

[0101] like Figure 9 As shown, the tray portion 63 has a corner portion 633 with a downwardly pointed corner portion. The corner portion 633 is located below the other end of the oil passage 627. In other words, a portion of the upper surface of the tray portion 63 is located below the oil passage 627.

[0102] Oil Route 628

[0103] Then, if Figure 1 and Figure 9 As shown, the oil circuit 628 is arranged at a position lower than the first bearing 41. In addition, the oil circuit 628 is an example of the "first circuit" of the present invention. The oil circuit 628 is a circuit for the lubricating fluid CL connecting the cover bearing retaining portion 623 and the second intermediate bearing retaining portion 624. One end of the oil circuit 628 is connected to the cover bearing retaining portion 623 via the first bearing 41. The other end of the oil circuit 628 is connected to the second intermediate bearing retaining portion 624 via the opening portion 6241. After being supplied to the first bearing 41, the lubricating fluid CL supplied to the cover bearing retaining portion 623 flows to the second intermediate bearing retaining portion 624 through the first bearing 41 and the oil circuit 628, and is supplied to the second intermediate bearing 316. As Figure 9 As shown, the second intermediate bearing retaining portion 624 is positioned axially to one side N relative to the first gear 331 and the tray portion 63. Specifically, because the second intermediate bearing retaining portion 624 is positioned deep relative to the first gear 331 and the tray portion 63, it is difficult for the lubricating fluid CL lifted up by the first gear 331 to be directly supplied from the tray portion 63. In contrast, the use of the oil passage 628 allows the lubricating fluid CL flowing out of the first bearing 41 to be easily supplied to the second intermediate bearing 316, thereby lubricating the second intermediate bearing 316. Therefore, the lubricating fluid CL can be directly supplied to a bearing located in a position where it is difficult to be supplied. Consequently, the bearing can be effectively lubricated.

[0104] The oil passage 628 has an inclined surface 6281. The inclined surface 6281 intersects obliquely with the axial and vertical directions, and slopes downward as it moves from one end of the oil passage 628 toward the other end. Thus, by allowing the lubricating fluid CL flowing out of the first bearing 41 to flow along the inclined surface 6281, the lubricating fluid CL can be supplied to the second intermediate bearing retaining portion 624. For example, the oil passage 628 further has a wall surface 6282. The wall surface 6282 is a portion of the end surface on the other axial side T of the cover bottom 622. The lubricating fluid CL flowing out of the first bearing 41 flows from the end on the other axial side T of the cover bearing retaining portion 623 along the wall surface 6282 onto the inclined surface 6281. The lubricating fluid CL then flows along the inclined surface 6281 toward the opening 6241 and is supplied to the second intermediate bearing retaining portion 624.

[0105] Preferably, at least the end portion on the other axial side T of one end portion of the oil passage 628 is positioned closer to the other axial side T than the first bearing 41. For example, at least the end portion on the other axial side T of the inclined surface 6281 is positioned closer to the other axial side T than the first bearing 41. This prevents the lubricating fluid CL flowing out of the first bearing 41 from excessively overflowing the oil passage 628 and allows it to flow through the one end portion of the oil passage 628. Consequently, the lubricating fluid CL can be efficiently supplied to the second intermediate bearing retaining portion 624.

[0106] Furthermore, the other end of the oil passage 628 is preferably connected to the end of the second intermediate bearing 316 on the one axial side N. For example, the lower end of the inclined surface 6281 (in other words, the end on the second intermediate bearing retaining portion 624 side) is connected to the end of the second intermediate bearing 316 on the one axial side N. This allows the lubricating fluid CL that has flowed into the other end of the oil passage 628 to be directly supplied to the second intermediate bearing 316. This lubricating fluid CL can efficiently lubricate the second intermediate bearing 316.

[0107] In this case, it is preferable that the end portion of the second intermediate bearing 316 on one axial side N is positioned closer to the other axial side T than the end portion of the first bearing 41 on one axial side N. This further shortens the shortest distance from one end to the other end of the oil passage 628. Consequently, the lubricating fluid CL flowing from the first bearing 41 to one end of the oil passage 628 can be easily supplied to the second intermediate bearing 316.

[0108] <Supply restriction member 629>

[0109] Next, refer to Figure 1 and Figure 10 The supply limiting member 629 will be described. Figure 10 It is a perspective view of the supply limiting component 629.

[0110] The supply limiting member 629 limits the supply amount of the lubricating fluid CL supplied from the cover bearing holder 623 to the first bearing 41. By this limitation, it is possible to ensure that the lubricating fluid CL is supplied from the cover bearing holder 623 to the motor 2 side through the inlet 220. The power transmission device 3 includes the supply limiting member 629. Figure 1 As shown, the supply limiting member 629 has an annular portion 6291 and a convex portion 6292 .

[0111] The annular portion 6291 is housed in the cap bearing retaining portion 623 and extends radially relative to the rotation axis J2. The annular portion 6291 is positioned closer to the axial side N than the first bearing 41, axially opposing the end of the first bearing 41 on the axial side N. In this manner, the annular portion 6291 can limit the amount of lubricating fluid CL supplied to the cap bearing retaining portion 623 that is supplied to the first bearing 41.

[0112] The annular portion 6291 has at least one through hole 6293. The through hole 6293 penetrates the annular portion 6291 in the axial direction. Figure 10 There are four through holes 6293, but this is not limited to this example. The number of through holes 6293 may be single or multiple. Preferably, the through hole 6293 is axially opposed to the inner ring and the outer ring of the first bearing 41. In this way, the lubricating fluid CL in the cover bearing retaining portion 623 can be supplied to the first bearing 41 through the through holes 6293. Furthermore, by adjusting the number of through holes 6293, the supply amount of the lubricating fluid CL to the first bearing 41 can be adjusted. Here, the annular portion 6291 may also be opposed to the first bearing 41 with a gap in the axial direction, but when the annular portion 6291 has the through hole 6293, it may also be in contact with the end portion on the axial side N of the first bearing 41.

[0113] In addition, the present invention is not limited to the above-described example, and the annular portion 6291 may not have the through-hole 6293. However, in this case, the annular portion 6291 faces the first bearing 41 with a gap in the axial direction.

[0114] Then, the convex portion 6292 extends from the radial inner end portion of the annular portion 6291 toward the other axial side T. The convex portion 6292 is inserted through the end portion of the axial side N of the cylindrical power shaft 22 extending in the axial direction, for example, Figure 1 As shown, the protrusion 6292 is inserted through the inlet 220 of the power shaft 22. Furthermore, it is preferable that the protrusion 6292 is not fixed to the end portion on the axial side N of the cylindrical power shaft 22. For example, the outer peripheral surface of the protrusion 6292 has a gap in the radial direction relative to the rotation axis J2, and faces the inner peripheral surface of the cylindrical power shaft 22. By inserting the protrusion 6292 through the end portion on the axial side N of the power shaft 22, it is possible to suppress displacement of the annular portion 6291 in the radial direction relative to the rotation axis J2 in a direction perpendicular to the axial direction.

[0115] In addition, the protrusion 6292 is cylindrical and extends in the axial direction, that is, it has a through hole (label omitted) extending in the axial direction. In this way, the interior of the cylindrical power shaft 22 can be connected to the interior of the cover bearing retaining portion 623 through the interior of the protrusion 6292. Therefore, the lubricating liquid CL supplied to the cover bearing retaining portion 623 can be supplied to the interior of the cylindrical power shaft 22 through the interior of the protrusion 6292. In addition, not limited to this example, the protrusion 6292 can also be columnar, that is, it can also have a shape that does not have a through hole (label omitted) extending in the axial direction. In this way, the amount of lubricating liquid CL supplied from the cover bearing retaining portion 623 to the interior of the power shaft 22 can be limited. Therefore, the lubricating liquid CL in the cover bearing retaining portion 623 supplied to the power shaft 22 and the first bearing 41 can be more appropriately distributed.

[0116] <Coolant circulation section 7>

[0117] The motor unit 1 includes a coolant circulation section 7 that circulates lubricating fluid CL. The coolant circulation section 7 includes a piping section 71 , a pump 72 , an oil cooler 73 , and a motor oil reservoir 74 .

[0118] The piping section 71 is formed in the motor housing 5. It connects the pump 72 to the motor oil reservoir 74 located within the motor housing body 51, supplying lubricating fluid CL to the motor oil reservoir 74. The pump 72 draws lubricating fluid CL from the lower region of the internal space 60. The pump 72 is an electric pump, but is not limited to this. For example, a configuration in which the pump is driven by a portion of the power of the power shaft 22 of the motor unit 1 may also be employed.

[0119] The oil cooler 73 is disposed between the pump 72 of the piping section 71 and the motor oil reservoir 74. Specifically, the lubricating fluid CL drawn by the pump 72 is transported via the piping section 71 through the oil cooler 73 to the motor oil reservoir 74. A refrigerant, such as water, supplied from an external source is supplied to the oil cooler 73. Heat exchange then occurs between the refrigerant and the lubricating fluid CL, lowering the temperature of the lubricating fluid CL. While the oil cooler 73 is liquid-cooled using a refrigerant, this is not limiting and may also be air-cooled, utilizing the wind from the vehicle's travel. The use of the oil cooler 73 reduces the temperature of the lubricating fluid CL supplied to the motor oil reservoir 74, thereby improving the cooling efficiency of the motor 2.

[0120] The motor oil reservoir 74 is a tray with an opening at the top, located in the upper region of the motor housing 5. Specifically, the motor oil reservoir 74 is located vertically above the stator 25 in the motor housing space 50. A drip hole is formed at the bottom of the motor oil reservoir 74, through which lubricating liquid CL drips to cool the motor 2. For example, the drip hole is formed above the coil end 271 of the coil 27 of the stator 25, and the coil 27 is cooled by the lubricating liquid CL.

[0121] <Lubricating and Cooling Operations of Motor Unit 1 and Power Transmission Device 3>

[0122] Next, the lubrication and cooling operations of the motor unit 1 and the power transmission device 3 will be described. The cooling of the motor 2 by the coolant circulation unit 7 is as described above, and therefore detailed description thereof will be omitted.

[0123] Lubricating fluid CL is stored in the internal space 60 of the gear housing 6. Furthermore, within the internal space 60 of the gear housing 6, the gear teeth of the first gear 331 of the differential device 33 are partially immersed in the lubricating fluid CL. The motor 2 rotates, transmitting rotation to the gear unit 30, thereby rotating the first gear 331. The rotation of the first gear 331 causes the gear teeth of the first gear 331 to stir up the lubricating fluid CL.

[0124] The lubricating liquid CL lifted up by the first gear 331 leaves the first gear 331 at its upper end. For example, when the peripheral speed of the gear teeth on the outer circumference of the first gear 331 is high, the speed of the lubricating liquid CL when leaving the first gear 331 is high, and a large amount of the lubricating liquid CL is scattered along the upper surface 60U of the internal space 60 of the gear housing 6. Therefore, most of the lubricating liquid CL lifted up by the first gear 331 passes between the upper portion of the protrusion 632 of the tray portion 63 and the upper surface 60U, and is accumulated in the tray portion 63. The lubricating liquid CL accumulated in the tray portion 63 flows from the oil passage 627 of the cover portion 62 into the cover bearing retaining portion 623.

[0125] A portion of the lubricating fluid CL within the cover bearing retaining portion 623 flows into the oil passage 628 via the first bearing 41. For example, the lubricating fluid CL supplied to the first bearing 41 passes between the inner and outer races of the first bearing 41 and flows out from the end portion on the other axial side T of the first bearing 41. The flowing lubricating fluid CL flows along the wall surface 6282 and onto the inclined surface 6281. The lubricating fluid CL on the inclined surface 6281 flows down along the inclined surface 6281. At least a portion of the lubricating fluid CL flows through the opening 6241 into the second intermediate bearing retaining portion 624, where it is then supplied to the second intermediate bearing 316, thereby lubricating the second intermediate bearing 316.

[0126] On the other hand, another portion of the lubricating fluid CL in the cover bearing holding portion 623 flows into the hollow portion 221 from the inlet 220 .

[0127] The lubricating liquid CL in the hollow portion 221 of the power shaft 22 is pulled axially toward the other side T by the negative pressure generated by the rotation of the power shaft 22. The lubricating liquid CL flowing in the hollow portion 221 is distributed toward the coil end portion 271 through the oil distribution holes provided in the power shaft 22. The lubricating liquid CL cools the coil 27. Furthermore, the lubricating liquid CL is also supplied to the third bearing 43 and the fourth bearing 44 disposed inside the motor housing 5 for lubrication and cooling. The lubricating liquid CL supplied to the motor housing 5 is stored in the lower portion of the motor housing 5 and returns to the internal space 60 of the gear housing 6 via a through-hole provided in the side plate portion 61.

[0128] A portion of the lubricating liquid CL contacts the surface of the side plate 61 on the axial side N and flows downward along the surface of the axial side N. The lubricating liquid CL that adheres to the upper portion of the groove 65 of the side plate 61 and flows downward flows into the groove 65 along the edge 654 at the upper end of the shaft opening 652 of the groove 65. Thus, the lubricating liquid CL that is lifted up by the first gear 331 and flows down along the surface of the side plate 61 on the axial side N can be guided along the upper edge 654 into the groove 65.

[0129] Furthermore, a portion of the lubricating liquid CL lifted by the first gear 331 is conveyed by the first gear 331 to a position below the upper end of the first gear 331 and exits the first gear 331. The lubricating liquid CL conveyed by the first gear 331 to a position below the upper end collides with the opposing surface 631 of the tray portion 63. The lubricating liquid CL in contact with the opposing surface 631 flows downward along the opposing surface 631. The guide portion 656 provided on the edge 655 below the shaft opening 652 of the groove 65 guides the lubricating liquid CL flowing downward along the opposing surface 631 of the tray portion 63 into the interior of the groove 65. This allows the lubricating liquid CL to efficiently flow into the differential device 33 and the first output bearing 341 disposed in the recess 64.

[0130] Furthermore, the groove portion 65 reaches the first bearing mounting portion 644 of the recessed portion 64. Furthermore, the inner peripheral surface 653 facing the peripheral opening 651 approaches the first bearing mounting portion 644 as it moves toward the first bearing mounting portion 644. Therefore, the lubricating fluid CL flowing into the groove portion 65 can be more efficiently supplied to the first output bearing 341.

[0131] Furthermore, because the groove 65 has a peripheral opening 651 and the peripheral opening 651 side of the groove 65 is inclined downward, a portion of the lubricating fluid CL that has flowed into the groove 65 flows out of the peripheral opening 651 into the recess 64 before reaching the first output bearing 341, and flows into the housing 332. This allows the housing 332 and the gears inside the housing 332 to be lubricated and cooled.

[0132] Because the tray portion 63 includes the protrusion 632, even if the circumferential speed of the outer circumferential surface of the first gear 331 is slow and the speed at which the lifted lubricating liquid CL leaves the first gear 331 is slow, the lubricating liquid CL that stalls midway will adhere to the upper surface of the protrusion 632 and flow into the tray portion 63. Consequently, a large amount of lubricating liquid CL can be supplied to the tray portion 63. Thus, a large amount of lubricating liquid CL can be supplied to various components via the tray portion 63, thereby improving the efficiency of lubrication and cooling of the first output bearing 341.

[0133] Because the protrusion 632 extends along the upper surface 60U of the internal space 60, an appropriate amount of the lubricating liquid CL lifted by the first gear 331 can be transferred to the tray portion 63. In other words, a certain amount of the lubricating liquid CL lifted by the first gear 331 can collide with the lower surface of the protrusion 632, thereby supplying a certain amount of lubricating liquid CL to the groove portion 65. This ensures a constant supply of lubricating liquid CL to the first output bearing 341 and the differential device 33 disposed in the recess 64. Furthermore, the gap between the tip of the protrusion 632 and the upper surface 60U of the internal space 60 of the gear housing 6 is larger than the gap between the tip of the protrusion 632 and the first gear 331. This allows most of the lifted lubricating liquid CL to be directed to the tray portion 63.

[0134] Furthermore, since the upper portion of the facing surface 631 is formed away from the first gear 331 , the tray portion 63 can be formed deeper, and even if a large amount of lubricating liquid CL is supplied to the tray portion 63 , the lubricating liquid CL can be received.

[0135] The lower end of the upper surface of the tray portion 63 is formed lower than the portion of the oil passage 627 connected to the tray portion 63. With this configuration, a certain amount of lubricating liquid CL can be retained in the tray portion 63, thereby preventing the lubricating liquid CL from being exhausted.

[0136] In the power transmission device 3 of this embodiment, a portion of the lubricating liquid CL lifted by the first gear 331 collides with the opposing surface 631 of the tray portion 63. The lubricating liquid CL flowing along the opposing surface 631 is guided to the groove portion 65. Within the internal space 60 of the gear housing 6, a certain amount of lubricating liquid CL can be supplied to the first output bearing 341, which is located at the end of the recessed portion 64 where the lubricating liquid CL is less likely to flow, thereby effectively lubricating and cooling the first output bearing 341.

[0137] While the embodiments and modifications of the present invention have been described above, the various structures and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the structures are possible without departing from the spirit of the present invention.

[0138] Industrial applicability

[0139] The power transmission device of the present invention can be used as a power transmission mechanism for transmitting the output from a power shaft of a motor, engine, etc. to the outside. The motor unit of the present invention can be used as a drive motor for vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and electric vehicles (EVs).

Claims

1. A power transmission device comprising: The gear portion is connected to one axial side of a first shaft rotatable about a first axis, wherein: The first axis extends along the horizontal direction; and a gear housing that houses the gear portion, The gear portion has: a first bearing supporting the first shaft so as to allow the first shaft to rotate; a second shaft rotatable about a second axis; and a second bearing supporting the second shaft so that the second shaft can rotate; The second axis is parallel to the first axis and is arranged below the first axis. The gear housing has: a first bearing holding portion that holds the first bearing; a second bearing holding portion that holds the second bearing; and The first passage is arranged below the first bearing. The first bearing holding portion and the second bearing holding portion are cylindrical and extend in the axial direction. The first bearing holding portion is supplied with lubricating liquid, The second bearing holding portion has an opening portion penetrating in a radial direction based on the second axis, and the opening portion is arranged below the first bearing. One end portion of the first passage is connected to the first bearing holding portion via the first bearing. The other end of the first passage is connected to the second bearing holding portion via the opening. The gear portion includes a first gear rotatable about a third axis parallel to the first axis. The gear housing comprises: a side plate portion, which is arranged at an end portion of the gear housing on the other side in the axial direction and extends in a direction intersecting the axial direction; a recessed portion, which is recessed from the side plate portion toward the other axial side and opens on one axial side; a tray portion extending axially toward one side from the side plate portion and opening upward; and a groove portion formed on one axial side surface of the side plate portion and having a circumferential opening opened to the inner circumferential surface of the recessed portion; The tray portion is arranged above the second axis and has an opposing surface that is at least radially opposed to the outer peripheral surface of the first gear. The groove portion is inclined downward from the opposing surface toward the circumferential opening.

2. The power transmission device according to claim 1, wherein: The second axis is arranged on one side of the first axis in a direction perpendicular to the axial direction and the up-down direction. The first passage has an inclined surface, The inclined surface obliquely intersects the axial direction and the up-down direction, and is inclined downward from the one end portion toward the other end portion of the first passage.

3. The power transmission device according to claim 1 or 2, wherein: At least the other axial side end portion of the one end portion of the first passage is arranged on the other axial side relative to the first bearing.

4. The power transmission device according to claim 1 or 2, wherein: The other end portion of the first passage is connected to one axial end portion of the second bearing.

5. The power transmission device according to claim 4, wherein: The end portion on one axial side of the second bearing is arranged closer to the other axial side than the end portion on one axial side of the first bearing.

6. The power transmission device according to claim 1 or 2, wherein: The power transmission device further includes a supply limiting member, which is housed in the first bearing holding portion and has an annular portion extending in a radial direction with respect to the first axis. The annular portion is arranged axially closer to one side than the first bearing and axially faces an end portion on one axial side of the first bearing.

7. The power transmission device according to claim 6, wherein: The annular portion has at least one through hole extending therethrough in the axial direction.

8. The power transmission device according to claim 6, wherein: The supply limiting member further includes a protrusion extending from the radially inner end portion of the annular portion toward the other axial side. The protrusion is inserted into one axial end portion of the cylindrical first shaft extending in the axial direction.

9. The power transmission device according to claim 8, wherein: The convex portion is in a cylindrical shape extending in the axial direction.

10. The power transmission device according to claim 1 or 2, wherein: The gear unit further comprises: a second gear disposed on an outer peripheral surface of the first shaft; a third gear disposed on the outer peripheral surface of the second shaft and meshing with the second gear; as well as a fourth gear disposed on the outer peripheral surface of the second shaft and meshing with the first gear; The lower end portion of the first gear is disposed inside the lubricating fluid stored in the lower portion of the gear housing. The gear housing also has: the tray portion is arranged radially outward of the first gear relative to the third axis; and a second passage connecting an axial end portion of the tray portion and the first bearing holding portion; The tray portion has a protrusion, and the protrusion faces the first gear in a radial direction with respect to the third axis. The protrusion extends in a direction approaching the outer peripheral surface of the first gear at an upper end portion of an end portion of the tray portion on the first gear side in a direction perpendicular to the axial direction.

11. A motor unit, wherein: The motor unit has: The power transmission device according to any one of claims 1 to 10; and A motor as a driving source.

12. A vehicle, wherein: This vehicle includes the motor unit according to claim 11 .

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