drive unit

Abstract

In the drive device, a first flow path includes: supplying a first fluid housed inside a transmission mechanism housing to a motor; and a first recovery path returning the first fluid supplied to the motor to the interior of the transmission mechanism housing. The motor housing has a first housing member and a second housing member. The transmission mechanism housing has a third housing member and a fourth housing member. The first housing member has a first opposing wall portion and a bearing retaining portion disposed in the first opposing wall portion. The third housing member has a second opposing wall portion axially facing the first opposing wall portion. The first opposing wall portion has a first opening portion opening both inside and outside the motor housing. The second opposing wall portion has a second opening portion opening both inside and outside the transmission mechanism housing. At least a portion of the first recovery path is formed by the first opening portion and the second opening portion.

Description

Technical Field

[0001] This invention relates to a driving device. Background Technology

[0002] A known drive device supplies oil stored in a housing that houses the power transmission mechanism to a rotary motor to cool the motor. For example, Patent Document 1 describes a vehicle drive device that discharges oil from a cooling pipe to the rotary motor.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-129608

[0006] The drive device described above includes a partition wall that separates the housing space for the rotary motor from the housing space for the power transmission mechanism. In Patent Document 1, the bearings supporting the rotor shaft of the rotary motor and the bearings supporting the rotating shaft of the power transmission mechanism are housed in the same partition wall. Therefore, it is difficult to independently separate the housing housing the rotary motor from the housing housing the power transmission mechanism. This results in the following problems: in the event of a malfunction in the rotary motor or the power transmission mechanism, it is difficult to separate only the faulty component, making replacement and repair difficult. Summary of the Invention

[0007] In view of the above, one of the objects of the present invention is to provide a drive device that can easily separate the motor from the transmission mechanism.

[0008] One embodiment of the drive device of the present invention includes: a motor having a rotor and a stator, the rotor being rotatable about a central axis, the stator covering the radially outer side of the rotor; a transmission mechanism connected to the motor; a housing having a motor housing and a transmission mechanism housing, the motor housing internally housing the motor, the transmission mechanism housing being fixed to one axial side of the motor housing and internally housing the transmission mechanism and a first fluid; and a first flow path for the first fluid to flow within it. The first flow path has: a supply path supplying the first fluid housed inside the transmission mechanism housing to the motor; and a first return path returning the first fluid supplied to the motor to the interior of the transmission mechanism housing. The motor housing has: a first housing member fixed to the transmission mechanism housing; and a second housing member fixed to the other axial side of the first housing member. The transmission mechanism housing has: a third housing member fixed to the first housing member; and a fourth housing member fixed to one axial side of the third housing member. The first housing member has: a first opposing wall portion facing the third housing member axially; and a bearing retaining portion disposed on the first opposing wall portion and retaining a bearing supporting the rotor for rotation. The third housing member has a second opposing wall portion facing the first opposing wall portion axially. The first opposing wall portion has a first opening that opens inside and outside the motor housing. The second opposing wall portion has a second opening that opens inside and outside the transfer mechanism housing. At least a portion of the first recycling path is formed by the first opening and the second opening.

[0009] According to one embodiment of the invention, in the drive device, the motor and the transmission mechanism can be easily separated independently. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of a drive device according to one embodiment, viewed from above.

[0011] Figure 2 This is a cross-sectional view of a drive device according to one embodiment, viewed from the rear.

[0012] Figure 3 This is a perspective view showing a portion of a first housing member in a motor housing according to one embodiment.

[0013] Figure 4This is a perspective view showing a portion of a second housing member in a motor housing according to one embodiment.

[0014] Figure 5 This is a cross-sectional perspective view showing a portion of the casing of one embodiment.

[0015] Figure 6 This is a diagram showing the first and second openings of one embodiment viewed from the axial side.

[0016] Figure 7 This is a cross-sectional perspective view showing a portion of the oil supply path in one embodiment.

[0017] Figure 8 This is a cross-sectional view showing a portion of the casing of one embodiment.

[0018] Figure 9 This is a perspective view showing a portion of the casing of one embodiment.

[0019] Figure 10 This is a diagram showing the first housing member in a motor housing of one embodiment, viewed from the other side of the axial direction.

[0020] Figure 11 This is a perspective view showing the positioning part of one embodiment.

[0021] Figure 12 This is a perspective view showing the first groove of one embodiment.

[0022] Figure 13 This is a diagram showing the second groove of one embodiment viewed from the axial side.

[0023] Figure 14 This is a cross-sectional perspective view showing a portion of a motor housing according to one embodiment.

[0024] Figure 15 This is a cross-sectional view showing a portion of the second flow path in one embodiment.

[0025] (Symbol Explanation)

[0026] 10. Outer casing;

[0027] 10a First bolt;

[0028] 10b Second bolt;

[0029] 10c Third bolt;

[0030] 11. Motor housing;

[0031] 11a Hole;

[0032] 12. Housing of the transmission mechanism;

[0033] 13 First outer shell component;

[0034] 13a First opposing wall portion;

[0035] 13e First opening;

[0036] 13p, 15q, 15r female threaded holes (bolt holes);

[0037] 13q, 14p, 16r fixing holes (through holes);

[0038] 14. Second outer shell component;

[0039] 13c First bearing retainer (bearing retainer);

[0040] 15. Third outer shell component;

[0041] 15a Second phase wall portion;

[0042] 15h Second opening;

[0043] 16. Fourth outer shell component;

[0044] 20 motors;

[0045] 30 rotors;

[0046] 31 Motor shaft;

[0047] 40 stators;

[0048] 50 Second flow path;

[0049] 60. Transmission mechanism;

[0050] 63 First gear shaft (gear shaft);

[0051] Bearings 71, 72, 73, and 74;

[0052] 90 First flow path;

[0053] 91. First supply path (supply route);

[0054] 92. Second supply flow path (supply route);

[0055] 93h flow path part;

[0056] 93j Flow path section (third opening);

[0057] 93x First recycling path;

[0058] 93y Second recycling path;

[0059] 100 Drive unit;

[0060] J1 central axis;

[0061] O oil (first fluid);

[0062] W Water (second fluid). Detailed Implementation

[0063] In the following description, the vertical direction is defined based on the positional relationship of the drive unit in the embodiment mounted on a vehicle located on a horizontal road surface. That is, when the drive unit is mounted on a vehicle located on a horizontal road surface, it is sufficient to satisfy at least the relative positional relationship with respect to the vertical direction described in the following embodiment.

[0064] In the accompanying drawings, the XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper vertical direction, and the -Z side is the lower vertical direction. In the following description, the upper vertical direction is simply referred to as the "upper side," and the lower vertical direction is simply referred to as the "lower side." The X-axis direction is the direction orthogonal to the Z-axis direction, and it is the front-rear direction of the vehicle on which the drive unit is mounted. In the following embodiments, the +X side is the front side of the vehicle, and the -X side is the rear side of the vehicle. The Y-axis direction is the direction orthogonal to both the X-axis and Z-axis directions, and it is the left-right direction of the vehicle, i.e., the vehicle width direction. In the following embodiments, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle. The front-rear and left-right directions are horizontal directions orthogonal to the vertical direction.

[0065] Furthermore, the front-to-back positional relationship is not limited to the positional relationship described in the following embodiments; it can also be that the +X side is the rear side of the vehicle and the -X side is the front side of the vehicle. In this case, the +Y side is the right side of the vehicle and the -Y side is the left side of the vehicle. In addition, in this specification, "parallel direction" also includes a substantially parallel direction, and "orthogonal direction" also includes a substantially orthogonal direction.

[0066] The central axis J1, appropriately shown in the figure, is an imaginary axis extending in a direction intersecting the vertical direction. More specifically, the central axis J1 extends along the Y-axis direction, which is orthogonal to the vertical direction, i.e., the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the central axis J1 will be simply referred to as "axial," the radial direction centered on the central axis J1 will be simply referred to as "radial," and the circumferential direction centered on the central axis J1, i.e., the direction around the central axis J1, will be simply referred to as "circumferential." In the following embodiments, the left side (+Y side) will be referred to as "axial side," and the right side (-Y side) will be referred to as "axial side."

[0067] The arrow θ shown appropriately in the diagram represents the circumferential direction. In the following description, the side of the circumferential direction that moves counterclockwise around the central axis J1 when viewed from the axial side (+Y side), i.e., the side in the direction of arrow θ (+θ side), is called the "circumferential side". The side of the circumferential direction that moves clockwise around the central axis J1 when viewed from the axial side, i.e., the side opposite to the side in the direction of arrow θ (-θ side), is called the "circumferential side".

[0068] Figure 1 and Figure 2 The drive unit 100 shown in this embodiment is a drive unit installed in a vehicle and rotating the axle 64. Vehicles equipped with the drive unit 100 are hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHVs), and electric vehicles (EVs), which use an electric motor as their power source. Figure 1 and Figure 2 As shown, the drive unit 100 includes: a motor 20; a transmission mechanism 60; a housing 10 having a motor housing 11 and a transmission mechanism housing 12, the motor housing 11 housing the motor 20 internally, and the transmission mechanism housing 12 housing the transmission mechanism 60 internally; bearings 71-76; an inverter unit 80; a rotation detection device 81; and a pump 94. The motor housing 11 and the transmission mechanism housing 12 are separate structures that are fixed to each other. The transmission mechanism housing 12 is fixed to one axial side of the motor housing 11. That is, the transmission mechanism housing 12 is connected to one axial side of the motor housing 11. The bearings 71-76 are, for example, ball bearings.

[0069] Motor 20 is the part that drives drive device 100. Motor 20 has: a rotor 30 that can rotate about a central axis J1 extending axially; and a stator 40 covering the radially outer side of rotor 30. Rotor 30 has motor shaft 31 and rotor body 32. Motor shaft 31 can rotate about the central axis J1. Motor shaft 31 is supported for rotation by bearings 71 and 72. Thus, bearings 71 and 72 support rotor 30 for rotation. In this embodiment, bearing 72 is equivalent to "first bearing".

[0070] In this embodiment, the motor shaft 31 is a hollow shaft with openings on both sides in the axial direction. The motor shaft 31 is cylindrical, extending axially around a central axis J1. The motor shaft 31 is entirely housed inside the motor housing 11. The motor shaft 31 is provided with a hole 33 connecting the interior of the motor shaft 31 to the exterior of the motor shaft 31. One end of the motor shaft 31 in the axial direction is supported by a bearing 72. The first gear shaft 63 of the reduction gear 61 (described later) is connected to the end of the motor shaft 31 in the axial direction. The rotor body 32 is fixed to the outer circumferential surface of the motor shaft 31. Although not shown in the figure, the rotor body 32 has a rotor core and a rotor magnet fixed to the rotor core.

[0071] The stator 40 is located radially outside the rotor 30. The stator 40 is fixed inside the motor housing 11. The stator 40 has a stator core 41 and a coil assembly 42. The stator core 41 is annular, surrounding the rotor 30. The coil assembly 42 has a plurality of coils 42c mounted circumferentially on the stator core 41. The plurality of coils 42c are mounted on the stator core 41 via an insulating member (not shown). Although not shown, the coil assembly 42 may have a bundling member for bundling the coils 42c, or a jumper wire for connecting the coils 42c to each other. The coil assembly 42 has a coil end 42a protruding from the stator core 41 toward one axial direction; and a coil end 42b protruding from the stator core 41 toward the other axial direction.

[0072] The transmission mechanism 60 is connected to the motor 20. The transmission mechanism 60 transmits the rotation of the rotor 30 to the vehicle axle 64. Figure 1 As shown, the transmission mechanism 60 of this embodiment includes: a reduction gear 61 connected to the motor 20; and a differential gear 62 connected to the reduction gear 61.

[0073] The reduction gear 61 includes a first gear shaft 63, a first gear 61a, a second gear 61b, a third gear 61c, and a second gear shaft 61d. The first gear shaft 63 is a gear shaft axially connected to the motor shaft 31. That is, in this embodiment, the transmission mechanism 60 has a first gear shaft 63 as a gear shaft axially connected to the motor shaft 31. In this embodiment, the first gear shaft 63 is a hollow shaft open on both sides axially. The first gear shaft 63 is cylindrical, extending axially about a central axis J1. The outer diameter of the first gear shaft 63 is smaller than the outer diameter of the motor shaft 31.

[0074] The first gear shaft 63 is connected to one axial side of the motor shaft 31. The end of the first gear shaft 63 on the other axial side is internally fitted into the end of the motor shaft 31 on one axial side. The first gear shaft 63 extends from the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. The motor shaft 31 and the first gear shaft 63 are interconnected by a spline fit. The first gear shaft 63 is supported by bearings 73 and 74 to enable rotation. In this embodiment, bearing 73 is equivalent to a "second bearing".

[0075] The first gear 61a is fixed to the portion of the first gear shaft 63 located inside the transmission mechanism housing 12. The second gear 61b and the third gear 61c are fixed to the second gear shaft 61d. The second gear 61b meshes with the first gear 61a. The second gear shaft 61d extends axially with a gear axis J2 extending parallel to the central axis J1 as its center. The gear axis J2 is an imaginary axis located below the central axis J1. For example, the gear axis J2 is located behind the central axis J1 (on the -X side). The second gear shaft 61d is supported by bearings 75 and 76 to enable rotation.

[0076] The differential 62 has a gear ring 62a. The gear ring 62a meshes with a third gear 61c. The lower end of the gear ring 62a is immersed in oil O stored in the transmission mechanism housing 12. Rotation of the gear ring 62a causes the oil O to be lifted. The lifted oil O is supplied, for example, as lubricating oil to the reduction gear 61 and the differential 62. The differential 62 causes the axle 64 to rotate about the differential axis J3. The differential axis J3 is an imaginary axis extending parallel to the central axis J1.

[0077] The motor housing 11 houses the rotor 30 and the stator 40. The motor housing 11 has a first housing member 13 and a second housing member 14.

[0078] The first housing member 13 is a cylindrical member that surrounds the motor 20 radially outward. In this embodiment, the inner circumferential surface of the first housing member 13 is cylindrical about the central axis J1. The first housing member 13 has an opening on the other axial side. The first housing member 13 is fixed to the transmission mechanism housing 12. A stator core 41 is fitted inside the first housing member 13. The first housing member 13 has: a first opposing wall portion 13a extending radially; a peripheral wall portion 13b extending axially from the radially outer peripheral edge of the first opposing wall portion 13a; and a first bearing retaining portion 13c provided in the first opposing wall portion 13a.

[0079] The first opposing wall portion 13a faces the transmission mechanism housing 12 axially. The first opposing wall portion 13a is located on the other axial side of the transmission mechanism housing 12. The first opposing wall portion 13a is fixed to the transmission mechanism housing 12. More specifically, the first opposing wall portion 13a faces the third housing member 15 (described later) axially and is fixed to the other axial side of the third housing member 15. The first opposing wall portion 13a has a hole 13d extending axially through the first opposing wall portion 13a. The hole 13d is a circular hole centered on the central axis J1. The first gear shaft 63 passes through the hole 13d axially.

[0080] like Figure 2As shown, the first opposing wall portion 13a has a first opening 13e, which opens both inside and outside the motor housing 11. The first opening 13e extends axially through the first opposing wall portion 13a. The first opening 13e is a through hole connecting the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a (described later) to the interior of the motor housing 11. The first opening 13e is provided in the portion of the first opposing wall portion 13a located lower than the first bearing retaining portion 13c. The lower end of the first opening 13e is connected to the inner circumferential surface of the peripheral wall portion 13b.

[0081] like Figure 3 As shown, the first opening 13e is approximately trapezoidal with rounded corners. The circumferential dimension of the first opening 13e increases as it moves radially outward. When viewed axially, the circumferential width of the first opening 13e intersecting the vertical direction expands downward in the vertical direction. In this embodiment, the circumferential center of the first opening 13e is offset to the other side (-θ side) circumferentially from the position located directly below the central axis J1.

[0082] In this embodiment, the first bearing retaining portion 13c is disposed on the axially opposite side of the first opposing wall portion 13a. The first bearing retaining portion 13c protrudes from the axially opposite side of the first opposing wall portion 13a toward the axially opposite side. Figure 3 As shown, the first bearing retaining portion 13c is cylindrical about a central axis J1. The first bearing retaining portion 13c has a through portion 13f that radially extends through it. In this embodiment, the through portion 13f radially extends through a portion of the first bearing retaining portion 13c located above and rearward (-X side) of the central axis J1. The through portion 13f extends rearwardly and obliquely upward from the inner circumferential surface of the first bearing retaining portion 13c to the outer circumferential surface of the first bearing retaining portion 13c. Figure 1 As shown, the first bearing retainer 13c internally retains the bearing 72.

[0083] The second outer casing member 14 is separate from the first outer casing member 13. The second outer casing member 14 is fixed to the opposite axial side of the first outer casing member 13. The second outer casing member 14 blocks the opening on the opposite axial side of the first outer casing member 13. Figure 4 As shown, the second outer casing member 14 has: a radially extending cover wall portion 14a; and a peripheral wall portion 14b extending from the radially outer peripheral edge of the cover wall portion 14a toward one axial side. Figure 1As shown, the axial end of the peripheral wall portion 14b contacts the axial end of the peripheral wall portion 13b in the first housing member 13. The cover wall portion 14a has a recess 14c that is recessed from the axial side of the cover wall portion 14a toward the axial side. The axial side portion of the recess 14c is the bearing retaining portion 14d that internally holds the bearing 71.

[0084] A retaining portion 14f protruding axially is provided on one side of the cover wall portion 14a. The retaining portion 14f surrounds the opening of the recess 14c on the axial side of the cover wall portion 14a. A rotation detection device 81 is held radially inside the retaining portion 14f. The rotation detection device 81 can detect the rotation of the rotor 30. In this embodiment, the rotation detection device 81 has: a detected portion 81a fixed to the motor shaft 31; and a detection portion 81b fixed to the second housing member 14. The detected portion 81a is annularly shaped surrounding the motor shaft 31. The detection portion 81b is held radially inside the retaining portion 14f. The detection portion 81b is annularly shaped surrounding the detected portion 81a.

[0085] In this embodiment, the rotation detection device 81 is a resolver. The detected part 81a is the resolver rotor. The detection part 81b is the resolver stator. By rotating the detected part 81a together with the motor shaft 31, an induced voltage corresponding to the circumferential position of the detected part 81a is generated in the coil of the detection part 81b. The rotation detection device 81 can detect the rotation of the detected part 81a and the motor shaft 31 based on the change in the induced voltage generated in the coil of the detection part 81b. Thus, the rotation detection device 81 can detect the rotation of the rotor 30. In this embodiment, the detection part 81b is fixed to the second housing member 14, which is separate from the first housing member 13. Therefore, an assembly method in which the detection part 81b is fixed to the second housing member 14 and then the second housing member 14 is fixed to the first housing member 13 can be adopted. Therefore, the rotation detection device 81 can be easily installed.

[0086] In this embodiment, an inverter unit 80 is mounted on the motor housing 11. The inverter unit 80 is fixed to the rear surface of the motor housing 11. Although not shown in the figure, the inverter unit 80 has an inverter circuit that is electrically connected to the stator 40.

[0087] The transmission mechanism housing 12 internally houses a speed reduction device 61 and a differential device 62. For example... Figure 2 As shown, the transmission mechanism housing 12 protrudes downwards from the motor housing 11. The lower bottom surface of the inner surface of the transmission mechanism housing 12 is located lower than the lower bottom surface of the inner surface of the motor housing 11. The transmission mechanism housing 12 has: a third housing member 15 fixed to the first housing member 13; and a fourth housing member 16 fixed to one axial side of the third housing member 15.

[0088] like Figure 1 As shown, the third housing member 15 has: a second opposing wall portion 15a extending radially; a peripheral wall portion 15b extending axially from the radially outer periphery of the second opposing wall portion 15a; a second bearing retaining portion 15c disposed in the second opposing wall portion 15a; and a bearing retaining portion 15d disposed in the second opposing wall portion 15a. The second opposing wall portion 15a faces the first opposing wall portion 13a axially. The second opposing wall portion 15a is fixed to the axial side of the first opposing wall portion 13a. The second opposing wall portion 15a has a hole 15f extending axially through the second opposing wall portion 15a. The hole 15f is a circular hole centered on the central axis J1. The first gear shaft 63 passes through the hole 15f axially.

[0089] The second opposing wall portion 15a has a recess 15e recessed on the axial side from the other side of the second opposing wall portion 15a. For example, when viewed axially, the inner periphery of the recess 15e is circular about the central axis J1. The opening on the other side of the axial direction of the recess 15e is blocked by the first opposing wall portion 13a. A space S is provided between the first opposing wall portion 13a and the second opposing wall portion 15a in the axial direction. The space S is formed by the interior of the recess 15e.

[0090] like Figure 2 As shown, the second opposing wall portion 15a has a second opening portion 15h, which opens both inside and outside the transmission mechanism housing 12. The second opening portion 15h axially penetrates the second opposing wall portion 15a. The second opening portion 15h is a through hole connecting the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a to the interior of the transmission mechanism housing 12. The second opening portion 15h is provided in the portion of the second opposing wall portion 15a located lower than the second bearing retaining portion 15c. The second opening portion 15h is provided at the end below the bottom surface of the recess 15e. The bottom surface of the recess 15e is the surface of the inner surface of the recess 15e located on one axial side and facing the other axial side. The lower end of the second opening portion 15h is connected to the inner circumferential surface of the recess 15e. More specifically, as... Figure 5 As shown, the lower end of the second opening 15h is connected to the bottom surface of the recess 15u provided on the lower side portion 15t of the inner circumferential surface of the recess 15e. The recess 15u is provided on one axial side of the lower side portion 15t. The recess 15u is recessed downwards and opens upwards and axially. The interior of the recess 15u is connected to the interior of the lower portion of the second opening 15h. The interior of the recess 15u opens into the interior of the transmission mechanism housing 12 via the second opening 15h.

[0091] The second opening 15h is positioned opposite to the first opening 13e located on one axial side of the first opposing wall portion 13a, separated by a gap. For example... Figure 6 As shown, when viewed axially, the first opening 13e and the second opening 15h overlap at least partially. In this embodiment, when viewed axially, the first opening 13e and the second opening 15h overlap by more than half. The second opening 15h protrudes downwards than the first opening 13e. The front (+X side) end of the first opening 13e protrudes forwards than the second opening 15h.

[0092] The second opening 15h is approximately an elongated oval with a circumferential dimension larger than its radial dimension. The circumferential dimension of the lower portion of the second opening 15h is larger than that of the upper portion. That is, when viewed axially, the circumferential width of the second opening 15h intersecting the vertical direction extends downwards in the vertical direction. In this embodiment, the circumferential center of the second opening 15h is offset to the other side (-θ side) circumferentially from the position directly below the central axis J1. Figure 5 and Figure 6 As shown, the opening area of ​​the opening end 15w of the second opening 15h, which is the opening inside the transmission mechanism housing 12, is greater than the opening area of ​​the opening end 13w of the first opening 13e, which is the opening inside the motor housing 11.

[0093] like Figure 2 As shown, in this embodiment, a partition wall 19 is formed by a first opposing wall portion 13a and a second opposing wall portion 15a, which separates the interior of the motor housing 11 from the interior of the transmission mechanism housing 12. That is, the housing 10 has a partition wall portion 19. The partition wall portion 19 has a through hole 19a connecting the interior of the motor housing 11 and the interior of the transmission mechanism housing 12. The through hole 19a extends axially through the partition wall portion 19. In this embodiment, the through hole 19a is formed by a first opening portion 13e provided in the first opposing wall portion 13a, an end portion below the recess 15e, and a second opening portion 15h provided in the second opposing wall portion 15a.

[0094] like Figure 1 As shown, in this embodiment, the second bearing retaining portion 15c and the bearing retaining portion 15d are provided on the axial side of the second opposing wall portion 15a. The second bearing retaining portion 15c and the bearing retaining portion 15d protrude from the axial side of the second opposing wall portion 15a towards the axial side. Figure 7 As shown, the second bearing retaining part 15c is cylindrical with the central axis J1 as its center. The bearing retaining part 15d is cylindrical with the gear axis J2 as its center. Figure 1 As shown, the second bearing retainer 15c internally retains the bearing 73. The bearing retainer 15d internally retains the bearing 75.

[0095] The fourth housing member 16 has: a cover wall portion 16a extending radially; a peripheral wall portion 16b extending axially from the radially outer peripheral edge of the cover wall portion 16a to the other side; and bearing retaining portions 16c and 16d provided on the cover wall portion 16a. The end of the peripheral wall portion 16b on the other side of the axial direction is in axial contact with the end of the peripheral wall portion 15b on one side of the axial direction of the third housing member 15.

[0096] In this embodiment, bearing retaining portions 16c and 16d are provided on the surface of the cover wall portion 16a on the axial side opposite to the axial side. The bearing retaining portions 16c and 16d protrude from the surface of the cover wall portion 16a on the axial side opposite to the axial side. Although not shown in the figures, the bearing retaining portion 16c is cylindrical with the central axis J1 as its center. The bearing retaining portion 16d is cylindrical with the gear axis J2 as its center. The bearing retaining portion 16c internally retains the bearing 74. The bearing retaining portion 16d internally retains the bearing 76.

[0097] like Figure 2 As shown, oil O is housed inside the transmission mechanism housing 12. Oil O is stored in the lower region within the transmission mechanism housing 12. Oil O serves as a refrigerant for cooling the motor 20. Oil O also serves as a lubricant for lubricating the reduction gear 61 and the differential gear 62. As oil O, for example, to perform the functions of both refrigerant and lubricant, it is preferable to use an oil with a low viscosity, similar to automatic transmission fluid (ATF). In this embodiment, oil O corresponds to the first fluid.

[0098] In this embodiment, a pump 94 is mounted on the housing 12 of the transfer mechanism. The pump 94 is mounted on the lower side of the housing 12 of the transfer mechanism. The pump 94 is a pump that causes oil O to flow within the second supply flow path 92, which will be described later. In this embodiment, the pump 94 is an electric pump. Alternatively, the pump 94 may also be a mechanical pump that is rotated by a first gear shaft 63 or a second gear shaft 61d.

[0099] Although the illustrations are omitted, the axial connections between the first housing member 13 and the second housing member 14, between the first housing member 13 and the third housing member 15, and between the third housing member 15 and the fourth housing member 16 are sealed by sealing members. The sealing members are, for example, liquid gaskets.

[0100] In this embodiment, the first outer casing member 13, the second outer casing member 14, the third outer casing member 15, and the fourth outer casing member 16 are fixed together by bolts. More specifically, as... Figure 8As shown, the first outer shell component 13 and the second outer shell component 14 are fixed to each other by a first bolt 10a. The first outer shell component 13 and the third outer shell component 15 are fixed to each other by a second bolt 10b. The third outer shell component 15 and the fourth outer shell component 16 are fixed to each other by a third bolt 10c. Multiple first bolts 10a, second bolts 10b, and third bolts 10c are respectively arranged around the central axis J1. That is, the second outer shell component 14 is fixed to the other side of the first outer shell component 13 by multiple first bolts 10a. The third outer shell component 15 is fixed to one side of the first outer shell component 13 by multiple second bolts 10b. The fourth outer shell component 16 is fixed to one side of the third outer shell component 15 by multiple third bolts 10c.

[0101] Multiple first bolts 10a respectively secure multiple first protrusions 13k disposed on the outer peripheral surface of the first housing member 13 to multiple second protrusions 14k disposed on the outer peripheral surface of the second housing member 14. The first protrusions 13k are located at an end on the opposite axial side of the outer peripheral surface of the first housing member 13. The first protrusions 13k protrude radially outward. Figure 9 and Figure 10 As shown, multiple first protrusions 13k are spaced apart circumferentially. Figure 10 As shown, in this embodiment, a plurality of first protrusions 13k are arranged at equal intervals along the circumference. In this embodiment, eight first protrusions 13k are provided.

[0102] In addition, in this specification, "an object is configured at equal intervals" includes the case where an object is configured at strictly equal intervals and the case where an object is configured at approximately equal intervals.

[0103] The first protrusion 13k has a female threaded opening 13p recessed on one axial side from the other side of the first protrusion 13k. In this embodiment, the female threaded opening 13p extends through the first protrusion 13k axially. Alternatively, the female threaded opening 13p may also be an opening with a bottom on one axial side. One female threaded opening 13p is provided for each first protrusion 13k. That is, in this embodiment, a total of eight female threaded openings 13p are provided. In this embodiment, the multiple female threaded openings 13p are arranged at equal intervals along the circumference.

[0104] like Figure 9As shown, a second protrusion 14k is provided at one end of the outer peripheral surface of the second housing member 14 on one axial side. The second protrusion 14k protrudes radially outward. A plurality of second protrusions 14k are arranged at intervals along the circumference. Although not shown in the figure, the plurality of second protrusions 14k are arranged at equal intervals along the circumference. For example, eight second protrusions 14k are provided. The axial side surface of each second protrusion 14k contacts the axial side surface of each first protrusion 13k.

[0105] The second protrusion 14k has a fixing hole 14p that extends through the second protrusion 14k axially. One fixing hole 14p is provided for each second protrusion 14k. For example, a total of eight fixing holes 14p are provided. The multiple fixing holes 14p are arranged at equal intervals along the circumference, for example. When viewed axially, each fixing hole 14p coincides with each female threaded hole 13p. Each first bolt 10a passes through each fixing hole 14p from the other side of the axial direction and is screwed into each female threaded hole 13p. Thus, the first housing member 13 and the second housing member 14 are fixed by the multiple first bolts 10a. Figure 10 As shown, multiple first bolts 10a are arranged at equal intervals around the circumference of the central axis J1.

[0106] like Figure 8 and Figure 9 As shown, multiple second bolts 10b respectively secure multiple third protrusions 13m disposed on the outer peripheral surface of the first housing member 13 and multiple fourth protrusions 15m disposed on the outer peripheral surface of the third housing member 15. The third protrusions 13m are disposed at an end on one axial side of the outer peripheral surface of the first housing member 13. The third protrusions 13m protrude radially outward. The multiple third protrusions 13m are spaced apart circumferentially. Figure 10 As shown, in this embodiment, a plurality of third protrusions 13m are arranged at equal intervals along the circumference. In this embodiment, eight third protrusions 13m are provided. The circumferential position of the third protrusions 13m is offset relative to the circumferential position of the first protrusions 13k. For example, the circumferential position of the third protrusions 13m is at the circumferential center between adjacent first protrusions 13k. In this embodiment, when viewed axially, the plurality of first protrusions 13k and the plurality of third protrusions 13m are arranged alternately along the circumferential direction.

[0107] The third protrusion 13m has a fixing hole 13q that extends through the third protrusion 13m along the axial direction. One fixing hole 13q is provided for each third protrusion 13m. That is, in this embodiment, a total of eight fixing holes 13q are provided. The multiple fixing holes 13q are arranged at equal intervals along the circumference.

[0108] like Figure 8 and Figure 9As shown, a fourth protrusion 15m is provided at the end of the outer peripheral surface of the third housing member 15 on the opposite side of the axial direction. The fourth protrusion 15m protrudes radially outward. A plurality of fourth protrusions 15m are arranged at intervals along the circumference. Although not shown in the figure, a plurality of fourth protrusions 15m are arranged at equal intervals along the circumference. For example, eight fourth protrusions 15m are provided. The axially opposite side surface of each fourth protrusion 15m contacts the axial side surface of each third protrusion 13m.

[0109] The fourth protrusion 15m has a female threaded opening 15q recessed on the axial side from the other side of the fourth protrusion 15m. In this embodiment, the female threaded opening 15q extends axially through the fourth protrusion 15m. Alternatively, the female threaded opening 15q may also be an opening with a bottom on the axial side. One female threaded opening 15q is provided for each fourth protrusion 15m. For example, a total of eight female threaded openings 15q are provided. The multiple female threaded openings 15q are arranged at equal intervals around the circumference, for example.

[0110] When viewed axially, each fixing hole 13q coincides with each female threaded hole 15q. Each second bolt 10b passes through each fixing hole 13q from the other side of the axial direction and is screwed into each female threaded hole 15q. Thus, the first outer casing member 13 and the third outer casing member 15 are fixed together by a plurality of second bolts 10b. Figure 10 As shown, a plurality of second bolts 10b are arranged at equal intervals around the central axis J1. In this embodiment, when viewed axially, a plurality of first bolts 10a and a plurality of second bolts 10b are arranged alternately around the central axis J1. When viewed axially, each second bolt 10b is located at the circumferential center between adjacent first bolts 10a in the circumferential direction.

[0111] Thus, in this embodiment, the first outer shell member 13 and the third outer shell member 15 are fixed to each other by a second bolt 10b screwed into the same side as the first bolt 10a that fixes the first outer shell member 13 and the second outer shell member 14. That is, the second bolt 10b that fixes the first outer shell member 13 and the third outer shell member 15 is inserted into the fixing hole 13q and the female threaded hole 15q in the same direction as the first bolt 10a that fixes the first outer shell member 13 and the second outer shell member 14.

[0112] like Figure 8As shown, the third bolt 10c secures the fifth protrusion 15n, located on one axial side of the outer peripheral surface of the third housing member 15, to the sixth protrusion 16n, located on the other axial side of the outer peripheral surface of the fourth housing member 16. Although not shown in the figure, multiple fifth and sixth protrusions 15n are provided at intervals in the circumferential direction. The fifth and sixth protrusions 15n and 16n protrude radially outward. The circumferential positions of the fifth and sixth protrusions 15n can be the same as those of the third and fourth protrusions 13m and 15m, or they can be offset circumferentially relative to the third and fourth protrusions 13m and 15m.

[0113] The fifth protrusion 15n has a female threaded opening 15r recessed from one axial side of the fifth protrusion 15n towards the other axial side. In this embodiment, the female threaded opening 15r extends axially through the fifth protrusion 15n. Alternatively, the female threaded opening 15r may also be an opening with a bottom on the other axial side. The sixth protrusion 16n has a fixing hole 16r extending axially through the sixth protrusion 16n. Each third bolt 10c passes through the fixing hole 16r from one axial side and is screwed into the female threaded opening 15r. Thus, the third housing member 15 and the fourth housing member 16 are fixed by a plurality of third bolts 10c.

[0114] Thus, in this embodiment, the third outer shell member 15 and the fourth outer shell member 16 are fixed to each other by a third bolt 10c screwed into the opposite side of the screwing-in side of the first bolt 10a that fixes the first outer shell member 13 and the second outer shell member 14, and the second bolt 10b that fixes the first outer shell member 13 and the third outer shell member 15. That is, the third bolt 10c that fixes the third outer shell member 15 and the fourth outer shell member 16 is inserted into the fixing hole 16r and the female threaded hole 15r in a different direction than the first bolt 10a that fixes the first outer shell member 13 and the second outer shell member 14, and the second bolt 10b that fixes the first outer shell member 13 and the third outer shell member 15.

[0115] In addition, in this embodiment, the female threaded openings 13p, 15q, and 15r are equivalent to "bolt openings". In this embodiment, the fixing holes 13q, 14p, and 16r are equivalent to "through holes".

[0116] As described above, in this embodiment, a plurality of first bolts 10a fixing the first outer shell member 13 and the second outer shell member 14 pass through fixing holes 14p, which are multiple through holes provided in the second outer shell member 14, from the other axial side, and are respectively fixed to female threaded holes 13p, which are multiple bolt holes provided in the first outer shell member 13. A plurality of second bolts 10b fixing the first outer shell member 13 and the third outer shell member 15 pass through fixing holes 13q, which are multiple through holes provided in the first outer shell member 13, from the other axial side, and are respectively fixed to female threaded holes 15q, which are multiple bolt holes provided in the third outer shell member 15. A plurality of third bolts 10c fixing the third outer shell member 15 and the fourth outer shell member 16 pass through fixing holes 16r, which are multiple through holes provided in the fourth outer shell member 16, from one axial side, and are respectively fixed to female threaded holes 15r, which are multiple bolt holes provided in the third outer shell member 15. In other words, the first outer shell member 13 and the third outer shell member 15 are fixed together axially on the same side as the side where the first outer shell member 13 is fixed to the second outer shell member 14 via the first bolt 10a, by the second bolt 10b. Therefore, the operations of fixing the first outer shell member 13 to the second outer shell member 14 and fixing the first outer shell member 13 to the third outer shell member 15 can be performed from the same axial side, which is the other axial side in this embodiment. This improves the ease of assembly of the outer shell 10.

[0117] In this embodiment, the transmission mechanism housing 12 is shaped to protrude radially outward from the motor housing 11. In this case, if bolts are to be inserted relative to the motor housing 11 from the side where the transmission mechanism housing 12 is located, i.e., the axial side, to fix the first housing member 13 and the third housing member 15, the bolt fixing portion needs to be positioned further outward to avoid interference with the transmission mechanism housing 12 itself. Therefore, the housing 10 can easily be made larger.

[0118] In contrast, for example, if the first housing member 13, the third housing member 15, and the fourth housing member 16 are tightened together by bolts inserted from one axial side, the first housing member 13 and the third housing member 15 can be fixed while preventing the housing 10 from becoming too large. However, in this case, when the bolts are removed to separate the motor housing 11 from the transmission mechanism housing 12, the third housing member 15 and the fourth housing member 16 constituting the transmission mechanism housing 12 will also separate. Therefore, the transmission mechanism housing 12 cannot be handled in its assembled state when it is not fixed to the motor housing 11. As a result, the assemblability of the housing 10 is easily compromised. Furthermore, the workability is easily compromised when performing maintenance on the drive unit 100 and replacing the transmission mechanism 60.

[0119] Furthermore, in the sealing members disposed axially between the first housing member 13 and the third housing member 15, and in the sealing members disposed axially between the third housing member 15 and the fourth housing member 16, the axial forces of the bolts required to properly maintain a seal are sometimes different. Therefore, when the first housing member 13, the third housing member 15, and the fourth housing member 16 are tightened together using the same bolt, it can sometimes be difficult to properly apply the axial force to the sealing members disposed between each housing member. This can easily lead to problems such as decreased sealing between the housing members and difficulty in adjusting the axial force of the bolts.

[0120] The problem described above, where the first housing member 13, the third housing member 15, and the fourth housing member 16 are tightened together by bolts inserted from one axial side, is the same when the first housing member 13, the second housing member 14, and the third housing member 15 are tightened together by bolts inserted from the other axial side.

[0121] To address the aforementioned problems, according to this embodiment, as described above, the first housing member 13 and the third housing member 15 are fixed together from the same axial direction as the side where the first housing member 13 is fixed to the second housing member 14 via the first bolt 10a, by the second bolt 10b. Therefore, even without changing the position of the portion fixed by the second bolt 10b to a more radially outward position, interference between the second bolt 10b and the transmission mechanism housing 12 can be suppressed. Thus, while suppressing the enlargement of the housing 10, the first housing member 13 and the third housing member 15 can be fixed together by the second bolt 10b. Furthermore, even if the second bolt 10b is removed, only the first housing member 13 and the third housing member 15 separate, while the third housing member 15 and the fourth housing member 16 remain connected. Therefore, even when not fixed to the motor housing 11, the transmission mechanism housing 12 can be processed in its assembled state. This suppresses the deterioration of the assemblability of the housing 10. Furthermore, it suppresses the deterioration of workability during maintenance of the drive unit 100 and replacement of the transmission mechanism 60. Furthermore, since the axial force can be changed separately by the second bolt 10b and the third bolt 10c, different axial forces can be applied to the sealing member located between the first housing member 13 and the third housing member 15, and to the sealing member located between the third housing member 15 and the fourth housing member 16. This allows for easy assurance of sealing between the housing members, and also facilitates easy adjustment of the axial force of the second bolt 10b and the third bolt 10c. The same applies to the sealing member between the first housing member 13 and the second housing member 14.

[0122] Furthermore, for example, if another housing member is disposed between the motor housing 11 and the transmission mechanism housing 12, and the motor housing 11 and the transmission mechanism housing 12 are fixed to this other housing member, the motor housing 11 and the transmission mechanism housing 12 can be separated in their assembled state. However, in this case, the number of components constituting the housing 10 increases accordingly with the provision of this other housing member. In contrast, according to this embodiment, as described above, the motor housing 11 and the transmission mechanism housing 12 can be separated in their assembled state without the provision of this other member. Therefore, the increase in the number of components constituting the housing 10 can be suppressed. In addition, since this other member can be omitted, the weight of the drive unit 100 can be reduced. Thus, even if the structure of the drive unit 100 is set as a water-cooled structure that cools the motor 20 by water W, as in this embodiment, the increase in the overall weight of the drive unit 100 can be suppressed.

[0123] Furthermore, according to this embodiment, a plurality of first bolts 10a that fix the first outer shell member 13 and the second outer shell member 14 respectively fix a plurality of first protrusions 13k provided on the outer peripheral surface of the first outer shell member 13 and a plurality of second protrusions 14k provided on the outer peripheral surface of the second outer shell member 14. In this way, by configuring the first protrusions 13k and second protrusions 14k to be partially protruding on the outer peripheral surface of each outer shell member, and fixing the first protrusions 13k and second protrusions 14k with the first bolts 10a, it is possible to prevent the first outer shell member 13 and the second outer shell member 14 from becoming radially larger throughout their entire circumference.

[0124] Furthermore, according to this embodiment, a plurality of second bolts 10b that fix the first outer shell member 13 and the third outer shell member 15 respectively fix a plurality of third protrusions 13m provided on the outer peripheral surface of the first outer shell member 13 and a plurality of fourth protrusions 15m provided on the outer peripheral surface of the third outer shell member 15. In this way, by constructing third protrusions 13m and fourth protrusions 15m that are partially protruding on the outer peripheral surface of each outer shell member, and fixing the third protrusions 13m and fourth protrusions 15m with the second bolts 10b, it is possible to prevent the first outer shell member 13 and the second outer shell member 15 from becoming radially larger throughout their entire circumference.

[0125] Furthermore, according to this embodiment, when viewed axially, the plurality of first bolts 10a and the plurality of second bolts 10b are alternately arranged around the central axis J1. Therefore, while stably fixing the first housing member 13, the second housing member 14, and the third housing member 15 by arranging the plurality of first bolts 10a and the plurality of second bolts 10b circumferentially, interference between one of the first bolts 10a and the second bolts 10b is prevented. Thus, when fixing the first housing member 13 to the second housing member 14 with the first bolts 10a and fixing the first housing member 13 to the third housing member 15 with the second bolts 10b from the same axial side, each operation is easily performed. Therefore, the assemblability of the housing 10 is improved.

[0126] Furthermore, according to this embodiment, a plurality of first bolts 10a are arranged at equal intervals along the circumference of the central axis J1. Therefore, the first housing member 13 and the second housing member 14 can be more stably fixed by the plurality of first bolts 10a. Furthermore, it is easy to ensure that the axial force applied to the sealing member located between the first housing member 13 and the second housing member 14 by the plurality of first bolts 10a is uniform throughout the entire circumference. Thus, it is easy to properly seal the first housing member 13 and the second housing member 14 throughout the entire circumference.

[0127] Furthermore, according to this embodiment, a plurality of second bolts 10b are arranged at equal intervals along the circumference of the central axis J1. Therefore, the first housing member 13 and the third housing member 15 can be more stably fixed by the plurality of second bolts 10b. Furthermore, it is easy to ensure that the axial force applied to the sealing member located between the first housing member 13 and the third housing member 15 by the plurality of second bolts 10b is uniform throughout the circumference. Thus, it is easy to properly seal the first housing member 13 and the third housing member 15 throughout the entire circumference.

[0128] In addition, such as Figure 9 As shown by the double-dotted line, the third protrusion 13m provided on the first housing member 13 can also extend axially. In this case, the end of the third protrusion 13m on the other axial side can be brought close to the first protrusion 13k. Therefore, when fixing the first housing member 13 to the third housing member 15 from the other axial side, the position of the clamp and tool used to tighten the second bolt 10b can be brought close to the position of the clamp and tool used when fixing the first housing member 13 to the second housing member 14. Furthermore, the axial dimension of the clamp and tool can be shortened. This improves the workability of fixing the first housing member 13 to the third housing member 15 with the second bolt 10b. In particular, the second bolt 10b can be properly tightened, thereby appropriately generating axial force.

[0129] Figure 9 The end of the third protrusion 13m, shown by the double-dotted line, is located, for example, on the other side of the axial direction, closer to the center of the first housing member 13. Figure 9 The end of the third protrusion 13m, shown by the double-dotted line, is located, for example, on the axial side closer to the end of the first protrusion 13k than on the axial side. This suppresses interference between the third protrusion 13m and the first protrusion 13k.

[0130] like Figure 3 and Figure 4 As shown, in this embodiment, the first outer casing member 13 and the second outer casing member 14 are further secured by a fourth bolt 10d, which is different from the aforementioned plurality of first bolts 10a. Figure 3 As shown, the first outer casing member 13 has a female threaded opening 13i recessed from the end face on the axial side of the peripheral wall portion 13b. The female threaded opening 13i is located between the groove portion 93a (described later) and the second circumferential flow path portion 52b of the second flow path 50 (described later). The female threaded opening 13i is located radially inside the second recycling path main body portion 93c (described later). The female threaded opening 13i is a bolt hole for screwing in and fixing the fourth bolt 10d.

[0131] like Figure 4 As shown, the second outer casing member 14 has a fixing hole 14e that serves as a through hole extending axially through the second outer casing member 14. The fixing hole 14e is located between the connecting portion 93b (described later) and the second circumferential flow path portion 52b of the second flow path 50 (described later). The fixing hole 14e is located radially inside the second recycling path main body portion 93c (described later). A fourth bolt 10d, passing through the fixing hole 14e from the other axial side, is screwed into the female threaded hole 13i. Thus, in this embodiment, the first outer casing member 13 and the second outer casing member 14 are fixed to each other at a position radially inside the recycling flow path 93 (described later) and adjacent to the second flow path 50 in the circumferential direction.

[0132] like Figure 11 As shown, the first housing member 13 has a positioning protrusion 13r disposed on the outer peripheral surface of the first housing member 13. The second housing member 14 has a positioning protrusion 14r disposed on the outer peripheral surface of the second housing member 14. The positioning protrusions 13r and 14r protrude radially outward. The positioning protrusion 13r has an opening 13s recessed from the axial side of the positioning protrusion 13r towards the axial side. The opening 13s is a circular opening with a bottom on the axial side. The positioning protrusion 14r has an opening 14s recessed from the axial side of the positioning protrusion 14r towards the axial side. The opening 14s is a circular opening with a bottom on the axial side. The openings 13s and 14s face each other in the axial direction.

[0133] Positioning protrusion 13r is circumferentially connected to a first protrusion 13k. Positioning protrusion 14r is circumferentially connected to a second protrusion 14k. Positioning protrusions 13r and 14r are in axial contact. Figure 10 As shown, in this embodiment, two positioning protrusions 13r are provided at intervals in the circumferential direction. The two positioning protrusions 13r are respectively provided on approximately opposite sides of the central axis J1 in the radial direction. Although not shown in the figure, two positioning protrusions 14r are also provided at intervals in the circumferential direction, similar to the positioning protrusions 13r.

[0134] like Figure 11 As shown, in this embodiment, the outer casing 10 has a positioning pin 10e, which positions the first outer casing member 13 and the second outer casing member 14 in the circumferential direction. The positioning pin 10e is cylindrical and extends axially. The positioning pin 10e is fitted into two holes: the orifice 13s of the positioning protrusion 13r of the first outer casing member 13 and the orifice 14s of the positioning protrusion 14r of the second outer casing member 14. Thus, the first outer casing member 13 and the second outer casing member 14 are positioned in the circumferential direction.

[0135] A portion of the locating pin 10e on one axial side is fitted into the orifice 13s. A portion of the locating pin 10e on the other axial side is fitted into the orifice 14s. (As...) Figure 10 As shown, in this embodiment, two locating pins 10e are provided. The two locating pins 10e are respectively located on approximately opposite sides of the central axis J1.

[0136] In addition, Figure 1 and Figure 2 The illustrations of the first protrusion 13k, the second protrusion 14k, the third protrusion 13m, the fourth protrusion 15m, the fifth protrusion 15n, the sixth protrusion 16n, and the positioning protrusions 13r and 14r are omitted. Figure 3 The illustrations of the first protrusion 13k and the positioning protrusion 13r are omitted. Figure 4 The illustrations of the second protrusion 14k and the positioning protrusion 14r are omitted. Figure 14 The illustrations of the first protrusion 13k, the second protrusion 14k, the third protrusion 13m, and the positioning protrusions 13r and 14r are omitted.

[0137] like Figure 2 As shown, the outer casing 10 has a first groove 17. The first groove 17 is located axially between the first opposing wall portion 13a and the second opposing wall portion 15a. That is, the first groove 17 is located in the space S. Figure 12As shown, the first groove 17 is a groove-shaped structure that opens upwards and extends axially. Oil O flows within the first groove 17. The first groove 17 is a storage section capable of storing oil O internally. In this embodiment, the first groove 17 is located rearward (on the -X side) from the central axis J1. The first groove 17 is located behind the hole 13d.

[0138] The first groove 17 connects the first opposing wall portion 13a and the second opposing wall portion 15a. In this embodiment, the first groove 17 has: a first portion 17a, which protrudes from one axial side (+Y side) of the first opposing wall portion 13a facing axially; and a second portion 17b, which protrudes from the other axial side (-Y side) of the second opposing wall portion 15a facing axially. The end of the first portion 17a on one axial side is connected to the end of the second portion 17b on the other axial side. The axial dimension of the second portion 17b is larger than the axial dimension of the first portion 17a.

[0139] The first groove 17 has: a bottom surface 17c facing upward; and a pair of side surfaces 17d, 17e projecting upward from both sides of the bottom surface 17c in a front-rear direction. The bottom surface 17c and the pair of side surfaces 17d, 17e extend axially. The bottom surface 17c and the pair of side surfaces 17d, 17e connect a first opposing wall portion 13a and a second opposing wall portion 15a. The pair of side surfaces 17d, 17e are axially spaced apart and arranged facing each other. Side surface 17d is located on the front side (+X side) of side surface 17e.

[0140] The bottom surface 17c is inclined vertically relative to the front-to-back direction. The bottom surface 17c is lower as it faces forward (+X side). In this embodiment, the bottom surface 17c is an inclined surface that is lower as it approaches the first hole 13g provided in the first opposing wall portion 13a. Therefore, oil O in the first groove portion 17 can be easily guided by gravity along the bottom surface 17c into the first hole 13g. The first hole 13g axially penetrates the first opposing wall portion 13a. The first hole 13g is, for example, a circular hole. The first hole 13g opens at its front end inside the first groove portion 17. The first hole 13g is connected to the bottom surface 17c and the side surface 17d.

[0141] like Figure 7 As shown, the first groove 17 is connected to the portion of the first opposing wall 13a located below the first hole 13g on one axial side and the portion of the second opposing wall 15a located below the second hole 15g on the other axial side. The second hole 15g extends axially through the second opposing wall 15a. The second hole 15g is, for example, a circular hole. The second hole 15g opens at the rear end (-X side) inside the first groove 17 and the front end (+X side) inside the second groove 18.

[0142] like Figure 2 As shown, the housing 10 has a second groove 18. The second groove 18 is located inside the housing 12 of the transmission mechanism. Figure 7 and Figure 13 As shown, the second groove 18 is a groove-shaped portion that opens upwards and extends axially. Oil O flows within the second groove 18. The second groove 18 is a storage portion capable of storing oil O internally. In this embodiment, the second groove 18 is located rearward (on the -X side) from the central axis J1. The second groove 18 is located above the bearing retaining portion 15d. Figure 7 As shown, the front (+X side) end of the second groove 18 is located on the axial side (+Y side) of the rear end of the first groove 17.

[0143] like Figure 2 As shown, the second groove 18 connects the second opposing wall portion 15a to the cover wall portion 16a. In this embodiment, the second groove 18 has: a first portion 18a, which protrudes from one axial side (+Y side) of the second opposing wall portion 15a towards the axial side; and a second portion 18b, which protrudes from the other axial side (-Y side) of the cover wall portion 16a towards the other axial side. The end of the first portion 18a on one axial side and the end of the second portion 18b on the other axial side are connected to each other.

[0144] like Figure 13 As shown, the second groove 18 has: a bottom surface 18c facing upward; and a pair of side surfaces 18d, 18e projecting upward from both sides of the bottom surface 18c in a front-rear direction. The bottom surface 18c and the pair of side surfaces 18d, 18e extend axially. The bottom surface 18c and the pair of side surfaces 18d, 18e connect the second opposing wall portion 15a to the cover wall portion 16a. The pair of side surfaces 18d, 18e are axially spaced apart and arranged facing each other.

[0145] Side 18d is located in front of side 18e (+X side). Side 18d is inclined in the front-rear direction relative to the vertical direction. Side 18d is forward (+X side) as it faces upward. In this embodiment, side 18d is an inclined surface that is downward as it approaches the second hole 15g. Therefore, it is easy to use gravity to guide the oil O entering the second groove 18 along side 18d into the second hole 15g.

[0146] Side 18e is inclined in the front-to-back direction relative to the vertical direction. Side 18e is further back (-X side) as it faces upward. Bottom 18c is inclined in the vertical direction relative to the front-to-back direction. Bottom 18c is further down (-X side) as it faces backward.

[0147] like Figure 7As shown, the second groove 18 is connected to the portion of the second opposing wall 15a located below the second hole 15g on one axial side. The second groove 18 is provided with supply holes 18f and 18g. The supply hole 18f connects the interior of the second groove 18 to the interior of the second bearing retaining portion 15c. Therefore, a portion of the oil O entering the second groove 18 is supplied to the bearing 73 within the second bearing retaining portion 15c via the supply hole 18f. Figure 13 As shown, the supply hole 18f opens on the side 18d. The supply hole 18f extends from the side 18d toward the front (+X side) and obliquely downward.

[0148] The supply hole 18g connects the interior of the second groove 18 to the interior of the bearing retainer 15d. Therefore, a portion of the oil O entering the second groove 18 is supplied to the bearing 75 within the bearing retainer 15d via the supply hole 18g. The supply hole 18g opens on the bottom surface 18c. The supply hole 18g extends downward and obliquely forward (+X side) from the bottom surface 18c.

[0149] like Figure 2 As shown, the housing 10 has a first flow path 90 and a second flow path 50. That is, the drive device 100 includes a first flow path 90 and a second flow path 50. The first flow path 90 is a flow path for oil O, which is a first fluid, to flow inside. The second flow path 50 is a flow path for water W, which is a second fluid, to flow inside. In this embodiment, oil O and water W function as refrigerants for cooling the stator 40. That is, in this embodiment, the second flow path 50 and the first flow path 90 are flow paths for water W, which is a refrigerant for cooling the stator 40. In this embodiment, at least a portion of the second flow path 50 and at least a portion of the first flow path 90 are constituted by a first housing member 13, a second housing member 14, and a third housing member 15. Therefore, the axial range for the second flow path 50 and the first flow path 90 can be easily increased, thereby facilitating the cooling of the stator 40.

[0150] Furthermore, in this specification, "flow path" refers to the path through which fluid flows. Therefore, the concept of "flow path" includes not only the "flow path" that forms a flow of fluid that always faces one direction, but also the path through which fluid is temporarily retained and the path through which fluid drips. Paths through which fluid is temporarily retained include, for example, storage sections for storing fluid.

[0151] At least a portion of the first flow path 90 is constituted by a first housing member 13 and a third housing member 15. In this embodiment, the first flow path 90 is constituted by a first housing member 13, a second housing member 14, and a third housing member 15. The first flow path 90 has a first supply flow path 91, a second supply flow path 92, a first recovery path 93x, and a second recovery path 93y. The first supply flow path 91 and the second supply flow path 92 are supply flow paths that supply oil O inside the transfer mechanism housing 12 to the inside of the motor housing 11. That is, the first supply flow path 91 and the second supply flow path 92 are supply paths that supply oil O housed inside the transfer mechanism housing 12 to the motor 20.

[0152] The first supply path 91 includes a lifting path 91a, a shaft supply path 91b, an internal shaft path 91c, and an internal rotor path 90a. The lifting path 91a is a path through which the oil O inside the transmission mechanism housing 12 is lifted by the rotation of the gear ring 62a of the differential device 62 to enter the second groove 18. The shaft supply path 91b is a path through which the oil O in the second groove 18 flows into the bearing holding portion 16c through a flow path (not shown) provided in the cover wall portion 16a, and then flows from the bearing holding portion 16c into the first gear shaft 63. In the shaft supply path 91b, the oil O is supplied to the bearing 74 held in the bearing holding portion 16c by flowing into the bearing holding portion 16c. In the shaft supply path 91b of this embodiment, the oil O flows in from the axial side end of the first gear shaft 63.

[0153] The internal path 91c is a path for oil O flowing into the first gear shaft 63 from one axial side of the first gear shaft 63, then flowing from the first gear shaft 63 into the motor shaft 31 and towards the other axial side. In other words, in this embodiment, the interior of the motor shaft 31 forms part of the first supply flow path 91. The internal path 90a is a path for oil O in the motor shaft 31 to pass through the bore 33, through the interior of the rotor body 32, and disperse into the stator 40. Thus, oil O is supplied to the rotor 30 and the stator 40 through the first supply flow path 91.

[0154] like Figure 1 As shown, the second supply flow path 92 has an inlet flow path 92a, a connecting flow path 92b, an internal shaft path 92c, and an internal rotor path 90a. The inlet flow path 92a extends axially from the interior of the transmission mechanism housing 12. More specifically, the inlet flow path 92a extends axially from the interior of the transmission mechanism housing 12 to the other side, passing through the second opposing wall 15a, the first opposing wall 13a, and the peripheral wall 13b to the second housing member 14. That is, the inlet flow path 92a has: a flow path portion 92d provided on the first housing member 13; a flow path portion 92e provided on the second housing member 14; and a flow path portion 92f provided on the third housing member 15.

[0155] Flow path portion 92f is connected to one axial side of flow path portion 92d. Therefore, the first flow path 90 can be appropriately increased axially through flow path portions 92d and 92f. Flow path portion 92e is connected to the other axial side of flow path portion 92d. Therefore, the first flow path 90 can be increased axially more appropriately through flow path portions 92d and 92e. Flow path portion 92f extends axially through the second opposing wall portion 15a and opens inside the transfer mechanism housing 12. Therefore, oil O inside the transfer mechanism housing 12 can flow from flow path portion 92f into the guide flow path portion 92a. Oil O drawn from the transfer mechanism housing 12 by pump 94 flows into the guide flow path portion 92a. Inside the guide flow path portion 92a, oil O flows axially to the other side.

[0156] like Figure 3 As shown, the flow path cross-section of the inlet flow path 92a is an elongated oval shape with a longer circumferential direction. The circumferential dimension of the inlet flow path 92a is smaller than that of the second recovery path main body 93c (described later), the first circumferential flow path 52a (described later), and the second circumferential flow path 52b (described later). Therefore, the circumferential dimension of the inlet flow path 92a can be relatively small. As a result, the pressure loss generated in the oil O flowing in the inlet flow path 92a can be reduced. Therefore, the oil O can be easily delivered into the inlet flow path 92a by the pump 94.

[0157] The inlet flow path 92a is located, for example, forward (+X side) and downward from the central axis J1. At least a portion of the inlet flow path 92a is located radially outward from the second flow path 50. In this embodiment, almost the entire inlet flow path 92a, except for its two axial ends, is located radially outward from the second flow path 50. The inlet flow path 92a is located below the second flow path 50.

[0158] like Figure 1As shown, a connecting flow path 92b is provided in the cover wall portion 14a of the second housing member 14. The connecting flow path 92b extends upward from the end on the other side of the axial direction of the inlet flow path 92a and connects to the recess 14c. Oil O flows into the recess 14c. A portion of the oil O flowing into the recess 14c is supplied to the bearing 71 held in the bearing retainer 14d. Another portion of the oil O flowing into the recess 14c flows into the motor shaft 31 from the other side of the axial direction. The shaft path 92c is a path through which oil O flowing into the motor shaft 31 from the end on the other side of the axial direction flows axially to one side within the motor shaft 31. That is, in this embodiment, the interior of the motor shaft 31 constitutes part of the second supply flow path 92. Thus, in this embodiment, oil O flows into the motor shaft 31 from both axial directions via the first supply flow path 91 and the second supply flow path 92. In other words, oil O is supplied to the interior of the motor shaft 31 from both axial directions. Therefore, for example, compared to the case where oil O flows in from only one end of the motor shaft 31, oil O can be properly flowed to the entire axial range of the motor shaft 31. That is, it can be prevented that oil O flowing in from one end of the motor shaft 31 does not reach the other end of the motor shaft 31, thus preventing oil O from flowing throughout the entire motor shaft 31. Therefore, it is easy to properly supply oil O to the bearings 71, 74 supporting the axial ends of the motor shaft 31 respectively. Similar to the shaft path 91c, oil O flowing in the shaft path 92c is supplied to the rotor 30 and stator 40 after passing through the rotor path 90a.

[0159] Oil O supplied to the stator 40 through the first supply flow path 91 and the second supply flow path 92 removes heat from the stator 40. The cooled oil O falls downwards and accumulates in the lower region inside the motor housing 11. The oil O accumulated in the lower region inside the motor housing 11 returns to the interior of the transfer mechanism housing 12 via the first recovery path 93x or the second recovery path 93y.

[0160] like Figure 2 As shown, the first recovery path 93x is a flow path that returns the oil O supplied to the motor 20 to the interior of the transfer mechanism housing 12. The first recovery path 93x extends from the interior of the motor housing 11 to the interior of the transfer mechanism housing 12. At least a portion of the first recovery path 93x is formed by a first opening 13e and a second opening 15h. In this embodiment, the first recovery path 93x is formed by the first opening 13e, a portion of the space S, and the second opening 15h. That is, the first recovery path 93x is formed by a through hole 19a. In this embodiment, the first recovery path 93x is configured to span the first housing member 13 and the third housing member 15.

[0161] The second recovery path 93y is a flow path that returns the oil O supplied to the motor 20 to the interior of the transfer mechanism housing 12. The second recovery path 93y extends from the interior of the motor housing 11 to the interior of the transfer mechanism housing 12. In this embodiment, the second recovery path 93y is configured to span the third housing member 15, the first housing member 13, and the second housing member 14. The second recovery path 93y is located below the motor 20. The second recovery path 93y has a groove 93a, a connecting portion 93b, and a second recovery path body portion 93c. The groove 93a is provided on the inner circumferential surface of the motor housing 11. In this embodiment, the groove 93a is recessed downward from the lower portion of the inner circumferential surface of the first housing member 13. The groove 93a extends axially. One axial end of the groove 93a is blocked. The other axial end of the groove 93a opens on the end face of the other axial side of the peripheral wall portion 13b. The other axial end of the groove 93a is connected to the connecting portion 93b.

[0162] The bottom surface of the groove 93a slopes downwards towards the opposite side of the axial direction. That is, the bottom surface of the groove 93a is an inclined surface that slopes downwards towards the connecting portion 93b. Therefore, oil O entering the groove 93a can be easily guided to the connecting portion 93b along the bottom surface of the groove 93a using gravity. The bottom surface of the groove 93a is the radially outer surface of its inner surface and faces radially inwards. In this embodiment, the bottom surface of the groove 93a faces upwards. Figure 14 As shown, the circumferential dimension of the groove 93a is smaller than the circumferential dimension of the first opening 13e.

[0163] The connecting portion 93b connects the groove portion 93a to the second recycling path main body portion 93c. The connecting portion 93b is also connected to the end portion 93f on the other axial side of the groove portion 93a. In this embodiment, the connecting portion 93b is provided on the peripheral wall portion 14b of the second housing member 14. The connecting portion 93b extends downward from the lower portion of the inner peripheral surface of the peripheral wall portion 14b. The connecting portion 93b opens upward. Figure 2 As shown, the lower end of the connecting portion 93b is connected to the axial end 93g of the second recycling path main body portion 93c. Thus, the connecting portion 93b connects the axial end 93f of the groove portion 93a to the axial end 93g of the second recycling path main body portion 93c.

[0164] The second recycling path main body 93c is located radially outward from the groove portion 93a. In this embodiment, the second recycling path main body 93c is located below the groove portion 93a. The second recycling path main body 93c extends axially and is connected to the interior of the transfer mechanism housing 12. The axial end 93p of the second recycling path main body 93c opens into the interior of the transfer mechanism housing 12. In this embodiment, the second recycling path main body 93c is configured to span the second housing member 14, the first housing member 13, and the third housing member 15. That is, the second recycling path main body 93c has: a flow path portion 93h provided in the first housing member 13; a flow path portion 93i provided in the second housing member 14; and a flow path portion 93j provided in the third housing member 15. The axial end 93k of the flow path portion 93h is connected to the axial end of the flow path portion 93j. The axial end 93m of the flow path portion 93h is connected to the axial end of the flow path portion 93i.

[0165] Thus, in this embodiment, the first flow path 90 includes: a flow path portion 93h; and a flow path portion 93j connected to one axial side of the flow path portion 93h. Therefore, the first flow path 90 can be appropriately increased axially by means of the flow path portions 93h and 93j. The flow path portion 93j extends axially through the second opposing wall portion 15a and opens inside the transfer mechanism housing 12. Therefore, oil O can be returned from the flow path portion 93j to the transfer mechanism housing 12.

[0166] In this embodiment, the flow path portion 93h corresponds to the axially extending flow path portion. That is, in this embodiment, the first housing member 13 has the flow path portion 93h as the axially extending flow path portion. In this embodiment, the flow path portion 93j corresponds to the "third opening" that opens into the interior of the transfer mechanism housing 12. The flow path portion 93j is provided on the second opposing wall portion 15a. That is, in this embodiment, the second opposing wall portion 15a has the flow path portion 93j as the third opening that opens into the interior of the transfer mechanism housing 12. Thus, in this embodiment, at least a portion of the second recycling path 93y is composed of the axially extending flow path portion 93h and the flow path portion 93j as the third opening.

[0167] The second recycling path main body 93c extends axially from the lower end of the connecting portion 93b, axially penetrating the first housing member 13 and the third housing member 15, and opening inside the transfer mechanism housing 12. Thus, in this embodiment, the first flow path 90, as a flow path extending axially from the interior of the motor housing 11 to the interior of the transfer mechanism housing 12, has the second recycling path main body 93c. The second recycling path main body 93c is located lower than the through hole 19a of the partition wall portion 19.

[0168] like Figure 3 and Figure 4 As shown, the flow path cross-section of the second recovery path main body 93c is longer in the circumferential direction. The circumferential dimension of the second recovery path main body 93c is larger than the circumferential dimension of the groove 93a and the circumferential dimension of the connecting part 93b. Therefore, the flow rate of oil O flowing in the second recovery path main body 93c can be increased. As a result, the amount of oil O returning from the motor housing 11 to the transmission mechanism housing 12 can be increased.

[0169] At least a portion of the main body 93c of the second recycling path is located radially outside the second flow path 50. Therefore, at least a portion of the second recycling path 93y is located radially outside the second flow path 50. Thus, in this embodiment, at least a portion of the second flow path 50 and the first flow path 90 overlap each other radially. In other words, when viewed radially, the second flow path 50 and the first flow path 90 have overlapping portions. Figure 14 As shown, a portion of the second recycling path main body 93c is located below the pair of axial flow paths 51 (described later), the first circumferential flow path 52c (described later), and the pair of second circumferential flow path sections 52b (described later) in the second flow path 50. The pair of axial flow path sections 51 are configured to circumferentially sandwich the groove 93a, the first circumferential flow path section 52c is located on one axial side of the groove 93a, and the pair of second circumferential flow path sections 52b are configured to circumferentially sandwich the connecting portion 93b. In this embodiment, as described above, the circumferential dimension of the second recycling path main body 93c is larger than the circumferential dimensions of the groove 93a and the connecting portion 93b. Therefore, the second recycling path main body 93c can protrude more circumferentially than the groove 93a and the connecting portion 93b. Therefore, the second recycling path main body 93c can be easily positioned radially outside the second flow path 50.

[0170] The second recovery path main body 93c is disposed adjacent to the inlet flow path 92a on one circumferential side (+θ side). That is, in this embodiment, the inlet flow path 92a and the second recovery path 93y are disposed adjacent to each other in the circumferential direction. In this embodiment, the portion of the motor housing 11 in which the second recovery path main body 93c and the inlet flow path 92a are disposed protrudes downward more than the other portions of the motor housing 11.

[0171] The second recycling path main body 93c is provided with a partition wall 93d, which circumferentially divides the interior of the second recycling path main body 93c. The partition wall 93d extends axially from one end 93p of the flow path portion 93h toward the other side. In this embodiment, the partition wall 93d extends from one end 93k of the flow path portion 93h to the axial center of the flow path portion 93h. In other words, the partition wall 93d extends from one end of the first housing member 13 to the axial center of the first housing member 13. The partition wall 93d divides the circumferentially longer second recycling path main body 93c into approximately two equal parts circumferentially. The partition wall 93d improves the strength of the portion of the housing 10 in which the second recycling path main body 93c is provided. Furthermore, it allows the axial force of the second bolt 10b to be transmitted more appropriately to the first housing member 13 and the third housing member 15.

[0172] Alternatively, the partition wall portion 93d may not extend to the axial center portion of the flow path portion 93h, that is, the axial center portion of the first housing member 13. For example, it can be configured in any position as long as the end 93r on the other side of the axial direction of the partition wall portion 93d is located on the other side of the axial direction of the flow path portion 93h and on the other side of the axial direction of the flow path portion 93h.

[0173] like Figure 3 As shown, the second recycling path main body 93c has a recessed portion 93e that is recessed radially inward. The recessed portion 93e is located at the circumferential center of the axially opposite portion of the second recycling path main body 93c. The outer peripheral surface of the portion of the motor housing 11 where the recessed portion 93e is provided is recessed radially inward. Thus, for example, interference between the second bolt 10b, which fixes the first housing member 13 and the third housing member 15, and the second recycling path main body 93c can be suppressed.

[0174] like Figure 1 and Figure 2 As shown, at least a portion of the second flow path 50 is located radially outside the motor 20. In this embodiment, almost the entire second flow path 50, except for its axial ends, is located radially outside the motor 20. The lower portion of the second flow path 50 lies between the second recovery path main body 93c and the motor 20 radially. Figure 14 and Figure 15 As shown, in this embodiment, the second flow path 50 extends in a rectangular wave shape along the circumferential direction. The second flow path 50 has a plurality of axial flow path portions 51, a plurality of first circumferential flow path portions 52a, and a plurality of second circumferential flow path portions 52b.

[0175] Multiple axial flow paths 51 extend axially. The multiple axial flow paths 51 are arranged at intervals in the circumferential direction. In this embodiment, the axial flow paths 51 are provided on the motor housing 11. More specifically, the axial flow paths 51 are provided on the first housing member 13. Figure 14 As shown, two of the multiple axial flow path sections 51 located on the lower side are arranged to sandwich the groove section 93a in the circumferential direction.

[0176] like Figure 1 As shown, the plurality of axial flow path portions 51 include two axial flow path portions 51c that are axially divided into two by a partition wall portion 51d. The axial flow path portion 51c has an upstream flow path portion 51a and a downstream flow path portion 51b. In this embodiment, the upstream flow path portion 51a is the portion of the axial flow path portion 51c located on the axial side relative to the partition wall portion 51d. In this embodiment, the downstream flow path portion 51b is the portion of the axial flow path portion 51c located on the opposite axial side relative to the partition wall portion 51d.

[0177] like Figure 15 As shown, in this embodiment, the axial flow path 51 is formed by at least a portion of the hole 11a that axially penetrates the first housing member 13. The axial flow path 51 is, for example, formed by the portion of the hole 11a excluding both axial ends. The opening on one axial side of the hole 11a is blocked by the third housing member 15. The opening on the other axial side of the hole 11a is blocked by the second housing member 14.

[0178] The first housing member 13 has a partition wall portion 52f that spaces between adjacent axial flow paths 51 in the circumferential direction. The partition wall portion 52f extends axially. The axial dimension of the partition wall portion 52f is smaller than the axial dimension of the first housing member 13. The partition wall portion 52f includes a first partition wall portion 52d and a second partition wall portion 52e. A plurality of first partition wall portions 52d and second partition wall portions 52e are provided and are arranged alternately in the circumferential direction.

[0179] The first partition wall portion 52d is a partition wall portion 52f that circumferentially separates a pair of axial flow path portions 51 connected by the first circumferential flow path portion 52a from each other. The axial end of the first partition wall portion 52d is configured to separate from the axial end face of the first housing member 13 toward the other axial side. The axial end of the first partition wall portion 52d is located at the axial end face of the first housing member 13 and contacts the axial surface of the second housing member 14.

[0180] The second partition wall portion 52e is a partition wall portion 52f that circumferentially separates a pair of axial flow path portions 51 connected by the second circumferential flow path portion 52b from each other. The axial end of the second partition wall portion 52e is configured to separate from the axial end face of the first housing member 13 toward one axial side. The axial end of the second partition wall portion 52e is located at the axial end face of the first housing member 13 and contacts the axial surface of the third housing member 15.

[0181] like Figure 14 As shown, the first circumferential flow path 52a and the second circumferential flow path 52b extend circumferentially. Multiple first circumferential flow path sections 52a are arranged at intervals in the circumferential direction. Multiple second circumferential flow path sections 52b are also arranged at intervals in the circumferential direction. The first circumferential flow path sections 52a are connected to each other at their axial ends on the opposite side of the circumferential direction of adjacent axial flow path sections 51. The second circumferential flow path sections 52b are connected to each other at their axial ends on the opposite side of the circumferential direction of adjacent axial flow path sections 51. By alternately connecting the axial ends of the axial flow path sections 51 with the first circumferential flow path sections 52a and the second circumferential flow path sections 52b, the second flow path 50 is made to have a rectangular wave shape.

[0182] The plurality of first circumferential flow path portions 52a include a first circumferential flow path portion 52c, which circumferentially crosses one side of the axial direction of the groove portion 93a. The first circumferential flow path portion 52c is the lowermost of the plurality of first circumferential flow path portions 52a. The circumferential dimension of the first circumferential flow path portion 52c is larger than the circumferential dimensions of the other first circumferential flow path portions 52a. For example... Figure 5 As shown, the first opening 13e and the second opening 15h are located above the portion on the other side (-θ side) of the first circumferential flow path 52c. The inner portion 52k of the first circumferential flow path 52c, located within the first housing member 13, is situated between the first opening 13e and the flow path portion 93h of the second recovery path 93y, located in the vertical direction. The outer portion 52m of the first circumferential flow path 52c, located within the third housing member 15, is situated between the second opening 15h and the flow path portion 93j of the second recovery path 93y, located in the vertical direction. In other words, in this embodiment, the second flow path 50 has: the portion located between the first opening 13e and the second recovery path 93y, i.e., the inner portion 52k; and the portion located between the second opening 15h and the second recovery path 93y, i.e., the outer portion 52m.

[0183] The plurality of second circumferential flow path portions 52b include a pair of second circumferential flow path portions 52b, which circumferentially sandwich the end portion and connecting portion 93b on the other side of the axial direction of the groove portion 93a. That is, in this embodiment, the end portion and connecting portion 93b on the other side of the axial direction of the groove portion 93a are located between adjacent second circumferential flow path portions 52b in the circumferential direction.

[0184] like Figure 15 As shown, in this embodiment, the first circumferential flow path 52a is provided to span the motor housing 11 and the transmission mechanism housing 12. More specifically, the first circumferential flow path 52a is provided to span the first housing member 13 and the third housing member 15. That is, at least a portion of the first circumferential flow path 52a is provided on the third housing member 15. Furthermore, at least a portion of the inner surface of the first circumferential flow path 52a is a surface of the third housing member 15. The first circumferential flow path 52a is configured such that a portion of the end face of the first housing member 13 provided on one axial side is axially connected to a first recess 52g recessed from the end face of the third housing member 15 on the other axial side. The first recess 52g is a groove that extends circumferentially and opens to the other axial side. Thus, the third housing member 15 has a first recess 52g recessed from the surface of the third housing member 15 on the other axial side.

[0185] In this embodiment, the interior of the first circumferential flow path portion 52a is formed by the interior of the first space portion 52i and the first recess 52g disposed on one axial side of the first partition wall portion 52d in the first housing member 13. The first space portion 52i includes, for example, a space portion adjacent to one axial side of the first partition wall portion 52d; and space portions located on both circumferential sides of the space portion adjacent to the first partition wall portion 52d. The space portions located on both circumferential sides of the space portion adjacent to the first partition wall portion 52d are connected to the axial side end of the interior of the axial flow path portion 51. The first space portion 52i includes the axial side end of the interior space of the hole 11a.

[0186] In this embodiment, the second circumferential flow path 52b is configured to span the first outer shell member 13 and the third outer shell member 14. That is, at least a portion of the second circumferential flow path 52b is disposed on the second outer shell member 14. Furthermore, at least a portion of the inner surface of the second circumferential flow path 52b is a surface of the second outer shell member 14. In addition, in this embodiment, the second flow path 50 is configured to span the first outer shell member 13 and the third outer shell member 14. The second circumferential flow path 52b is configured such that a portion of the end face of the first outer shell member 13 disposed on the other axial side is axially connected to a second recess 52h recessed from the end face of the second outer shell member 14 on one axial side toward the other axial side. The second recess 52h is a groove that extends circumferentially and opens toward one axial side. Thus, the second outer shell member 14 has a second recess 52h recessed from the surface of the second outer shell member 14 on one axial side toward the other axial side.

[0187] In this embodiment, the interior of the second circumferential flow path portion 52a is formed by the interior of the second space portion 52j and the second recess 52h disposed on the axially opposite side of the second partition wall portion 52e in the first housing member 13. The second space portion 52j includes, for example, a space portion adjacent to the axially opposite side of the second partition wall portion 52e; and space portions located on both circumferentially sides of the space portion adjacent to the second partition wall portion 52e. The space portions located on both circumferentially sides of the space portion adjacent to the second partition wall portion 52e are connected to the axially opposite end portion inside the axial flow path portion 51. The second space portion 52j includes the axially opposite end portion inside the internal space of the hole 11a.

[0188] Within the axial flow path 51, water W flows axially. Within adjacent circumferential axial flow path sections 51, the directions of water W flow are opposite to each other. Within the first circumferential flow path section 52a and the second circumferential flow path section 52b, water W flows towards one circumferential side (in the +θ direction). The first circumferential flow path section 52a connects the end of the axial flow path section 51 where water W flows towards one axial side to the end of the axial flow path section 51 where water W flows towards the other axial side. The second circumferential flow path section 52b connects the end of the axial flow path section 51 where water W flows towards the other axial side to the end of the axial flow path section 51 where water W flows towards one axial side.

[0189] like Figure 1As shown, the second flow path 50 has an inflow flow path 53a and an outflow flow path 53b. In this embodiment, the inflow flow path 53a and the outflow flow path 53b pass through the interior of the inverter unit 80. Water W flows into the inflow flow path 53a from outside the drive unit 100. The water W flowing into the inflow flow path 53a flows into the upstream flow path 51a. The water W flowing into the upstream flow path 51a flows along a rectangular wave-shaped flow path formed by the axial flow path 51, the first circumferential flow path 52a, and the second circumferential flow path 52b, and flows around the motor 20 once, flowing from the downstream flow path 51b into the outflow flow path 53b. The water W flowing into the outflow flow path 53b flows out to the outside of the drive unit 100.

[0190] like Figure 8 As shown, the fastening surfaces 13x and 14x of the first outer shell member 13 and the second outer shell member 14, which are fixed to each other by the first bolt 10a, are sealing surfaces that seal a portion of the second flow path 50 in the connection portion of the first outer shell member 13 and the second outer shell member 14. That is, the axial direction between the portion of the first outer shell member 13 constituting the second flow path 50 and the portion of the second outer shell member 14 constituting the second flow path 50 is sealed. Therefore, even if the first outer shell member 13 and the second outer shell member 14 constitute at least a portion of the second flow path 50, leakage of water W from the second flow path 50 can be suppressed.

[0191] The fastening surface 13x is the surface on the other side of the axial direction of the first housing member 13. The fastening surface 14x is the surface on one side of the axial direction of the second housing member 14. Furthermore, the fastening surfaces 13x and 14x are also sealing surfaces that seal a portion of the first flow path 90 in the connection between the first housing member 13 and the second housing member 14. Therefore, a portion of the second flow path 50 and a portion of the first flow path 90 in the connection between the first housing member 13 and the second housing member 14 can be sealed together by the first bolt 10a. Thus, compared to sealing the second flow path 50 and the first flow path 90 separately using different bolts, the housing 10 can be assembled more easily. Furthermore, the number of components in the drive unit 100 can be easily reduced.

[0192] The fastening surfaces 13y and 15y of the first outer shell member 13 and the second outer shell member 15, which are fastened to each other by the second bolt 10b, are sealing surfaces that seal a portion of the second flow path 50 in the connection between the first outer shell member 13 and the second outer shell member 15. That is, the axial direction between the portion of the first outer shell member 13 constituting the second flow path 50 and the portion of the third outer shell member 15 constituting the second flow path 50 is sealed. Therefore, even if at least a portion of the second flow path 50 is formed by the first outer shell member 13 and the third outer shell member 15, leakage of water W from the second flow path 50 can be suppressed.

[0193] The fastening surface 13y is the surface on one axial side of the first housing member 13. The fastening surface 15y is the surface on the other axial side of the third housing member 15. Furthermore, the fastening surfaces 13y and 15y are also sealing surfaces that seal a portion of the first flow path 90 in the connection between the first housing member 13 and the third housing member 15. Therefore, a portion of the second flow path 50 and a portion of the first flow path 90 in the connection between the first housing member 13 and the third housing member 15 can be sealed together by the second bolt 10b. Thus, compared to sealing the second flow path 50 and the first flow path 90 separately using different bolts, it is easier to assemble the housing 10. Furthermore, it is easier to further reduce the number of components in the drive unit 100.

[0194] like Figure 2 As shown, the housing 10 has an oil supply path 95. The oil supply path 95 extends axially through a second opposing wall portion 15a from the interior of the transmission mechanism housing 12. In this embodiment, the oil supply path 95 extends axially through a first opposing wall portion 13a and extends into the interior of the motor housing 11. Figure 7 As shown, the oil supply path 95 has a supply port 13h, which supplies oil O to the bearing 72 held in the first bearing holding portion 13c. In this embodiment, the supply port 13h is an opening in the first hole portion 13g that opens on the surface opposite to the axial direction of the first opposing wall portion 13a. The supply port 13h opens inside the motor housing 11. Figure 3 As shown, the supply port 13h is located above the central axis J1. The supply port 13h opens inside the through portion 13f. When viewed axially, the supply port 13h overlaps with the through portion 13f.

[0195] In this embodiment, the oil supply path 95 includes a first orifice 13g, a second orifice 15g, a first groove 17, and a second groove 18. For example... Figure 7 As indicated by the dashed arrow, a portion of the oil O that enters the second groove 18 after being lifted by the gear ring 62a flows through the second hole 15g into the first groove 17 within the space S. The oil O flowing into the first groove 17 flows within the first groove 17, passes through the first hole 13g, and is supplied to the motor housing 11 from the supply port 13h. The oil O discharged from the supply port 13h flows through the through-hole 13f into the interior of the first bearing retaining portion 13c and is supplied to the bearing 72.

[0196] According to this embodiment, at least a portion of the second flow path 50 is located radially outside the motor 20. Therefore, the motor 20 can be cooled by the water W flowing within the second flow path 50. Therefore, the stator 40 can be cooled by the water W flowing within the second flow path 50. Furthermore, at least a portion of the second recovery path 93y is located radially outside the second flow path 50. Therefore, the second recovery path 93 can be configured close to the second flow path 50. As a result, the oil O passing through the second recovery path 93y can be easily cooled by the water W flowing within the second flow path 50. Therefore, the temperature of the oil O flowing into the transfer mechanism housing 12 from the second recovery path 93y can be reduced. Therefore, the temperature of the oil O supplied from the transfer mechanism housing 12 to the motor housing 11 through the first supply flow path 91 and the second supply flow path 92 can be relatively low. As a result, the motor 20 housed in the motor housing 11 can be supplied with lower temperature oil O. Therefore, the motor 20 can be appropriately cooled by the lower temperature oil O. Thus, in this embodiment, the motor 20 can be appropriately cooled by water W and oil O. Therefore, the cooling efficiency of the motor 20 can be improved. Furthermore, the motor 20 can be easily cooled even without a cooler such as an oil cooler for cooling the oil O. Therefore, the number of components in the drive unit 100 can be reduced accordingly compared to not having a cooler.

[0197] Furthermore, according to this embodiment, the second flow path 50 extends in a rectangular wave shape along the circumferential direction. Therefore, the portion of the housing 10 in which the second flow path 50 is provided can be expanded, and the motor 20 can be cooled more appropriately by the water W flowing within the second flow path 50. Thus, the cooling efficiency of the motor 20 can be further improved. Furthermore, when the housing 10 is divided into multiple components as in this embodiment, the second flow path 50 is easily manufactured by constructing the second flow path 50 from the various components constituting the housing 10.

[0198] According to this embodiment, at least a portion of the second flow path 50 is constituted by the first housing member 13 and the third housing member 15. Therefore, it is easy to extend the second flow path 50 towards the axial side where the transmission mechanism housing 12 is located. This allows for proper cooling of the motor 20 via the second flow path 50. Here, in this embodiment, as described above, the motor housing 11 and the transmission mechanism housing 12 are each assembled from two housing members, thereby allowing the motor housing 11 to be separated from the transmission mechanism housing 12. Because of this structure, the second flow path 50 can be constructed using the third housing member 15 constituting the transmission mechanism housing 12, making it easier and more appropriate to provide a larger axial dimension for the second flow path 50. In this embodiment, the second flow path 50 can be extended to a position axially closer to the bearing 72 held in the first opposing wall portion 13a. As described above, according to this embodiment, the axial dimension of the second flow path 50 provided in the housing 10 can be increased. Therefore, the cooling efficiency of the motor 20 achieved by the second flow path 50 can be improved.

[0199] Furthermore, in this embodiment, at least a portion of the first circumferential flow path 52a is disposed on the third housing member 15. Therefore, a portion of the second flow path 50 can also be disposed on the third housing member 15. This allows the second flow path 50 to be appropriately increased axially, and the motor 20 can be cooled more appropriately and easily. Furthermore, in this embodiment, at least a portion of the second circumferential flow path 52b is disposed on the second housing member 14. Therefore, a portion of the second flow path 50 can also be disposed on the second housing member 14. This allows the second flow path 50 to be appropriately increased axially, and the motor 20 can be cooled more appropriately and easily.

[0200] Furthermore, in this embodiment, by providing a hole 11a that extends axially through the first outer casing member 13, and by using the second outer casing member 14 and the third outer casing member 15 to block both axial sides of the hole 11a, the second flow path 50 can be easily manufactured. In this embodiment, the opening on one axial side of the hole 11a is blocked by the third outer casing member 15, and the opening on the other axial side of the hole 11a is blocked by the second outer casing member 14. At least a portion of the inner surface of the first circumferential flow path portion 52a is a surface of the third outer casing member 15. At least a portion of the inner surface of the second circumferential flow path portion 52b is a surface of the second outer casing member 14. Therefore, the second flow path 50 can be easily manufactured.

[0201] Furthermore, according to this embodiment, the first outer casing member 13 has a spacer wall portion 52f that spaces apart adjacent axial flow path portions 51 in the circumferential direction. The axial dimension of the spacer wall portion 52f is smaller than the axial dimension of the first outer casing member 13. Therefore, a gap can be provided in at least one of the axial directions between the spacer wall portion 52f and the second outer casing member 14 and between the spacer wall portion 52f and the third outer casing member 15. Thus, by using this gap to fix at least one of the second outer casing member 14 and the third outer casing member 15 to the first outer casing member 13, a part of the second flow path 50 can be easily formed.

[0202] Specifically, in this embodiment, the axial end of the first partition wall portion 52d is located on the opposite axial side than the axial end of the first housing member 13. Therefore, a first space portion 52i is provided between the first partition wall portion 52d and the third housing member 15 in the axial direction. The interior of the first circumferential flow path portion 52a is formed by the first space portion 52i and the interior of the first recess 52g provided in the first housing member 13 on the axial side of the first partition wall portion 52d. Thus, the first circumferential flow path portion 52a can be easily manufactured to span the first housing member 13 and the third housing member 15.

[0203] Furthermore, in this embodiment, the end of the second partition wall portion 52e on the other axial side is located axially closer to the end of the first housing member 13 on the other axial side. Therefore, a second space portion 52j is provided between the second partition wall portion 52e and the second housing member 14 in the axial direction. The interior of the second circumferential flow path portion 52b is formed by the interior of the second space portion 52j and the second recess 52h provided in the first housing member 13 on the other axial side of the second partition wall portion 52e. Thus, the second circumferential flow path portion 52b can be easily manufactured to span the first housing member 13 and the second housing member 14.

[0204] Furthermore, according to this embodiment, the first circumferential flow path 52a is arranged to span the first housing member 13 and the third housing member 15. Therefore, compared to, for example, the first circumferential flow path 52a being entirely disposed in the third housing member 15, the axial enlargement of the third housing member 15 can be suppressed. Thus, the axial enlargement of the drive device 100 can be suppressed. Furthermore, since the second flow path 50 is appropriately extended to a position axially closer to the stator 40, the range of the stator 40 that can be cooled by the second flow path 50 can be expanded. Therefore, the motor 20 can be cooled more appropriately by the water W flowing within the second flow path 50.

[0205] Furthermore, according to this embodiment, the first bearing holding portion 13c is provided on the axial side opposite to the first opposing wall portion 13a. Therefore, by forming at least a portion of the second flow path 50 with the first housing member 13 and the third housing member 15, a portion of the second flow path 50 can be easily positioned on the axial side relative to the bearing 72 held in the first bearing holding portion 13c. This allows for a more appropriate increase in the axial dimension of the second flow path 50 relative to the motor 20. Furthermore, the bearing 72 is housed inside the motor housing 11. Therefore, when separating the motor housing 11 from the transmission mechanism housing 12, the motor housing 11 and the motor 20 can be easily and appropriately processed as a unit.

[0206] Furthermore, according to this embodiment, the transmission mechanism 60 has a first gear shaft 63 axially connected to the motor shaft 31. The motor shaft 31 and the first gear shaft 63 are interconnected by a spline engagement. Therefore, by separating the motor shaft 31 and the first gear shaft 63 axially, the connection between the motor shaft 31 and the first gear shaft 63 can be released. Thus, when separating the motor housing 11 and the transmission mechanism housing 12 axially, the connection between the motor 20 and the transmission mechanism 60 can be easily released. Therefore, the motor housing 11 and the transmission mechanism housing 12 can be easily separated. Furthermore, when connecting the motor housing 11 and the transmission mechanism housing 12 axially, the motor 20 and the transmission mechanism 60 can be easily connected axially. Therefore, the separated motor housing 11 and the transmission mechanism housing 12 can be easily connected.

[0207] Furthermore, according to this embodiment, the third housing member 15 has a second bearing retaining portion 15c provided on one axial side of the second opposing wall portion 15a. Therefore, the bearing 73 supporting the first gear shaft 63 so that it can rotate is housed inside the transmission mechanism housing 12. Thus, when the transmission mechanism housing 12 is separated from the motor housing 11, the transmission mechanism housing 12 and the transmission mechanism 60 can be easily and appropriately processed as a unit.

[0208] Furthermore, according to this embodiment, the first flow path 90 has a first recovery path 93x, which returns the oil O supplied to the motor 20 to the interior of the transfer mechanism housing 12. At least a portion of the first recovery path 93x is formed by a first opening 13e and a second opening 15h. Therefore, the oil O supplied to the motor 20 by the first supply flow path 91 and the second supply flow path 92 can be returned from the motor housing 11 to the transfer mechanism housing 12 via the first recovery path 93x.

[0209] In structures where fluids such as oil O move between the motor housing 11 and the transmission mechanism housing 12 for cooling or other purposes, it has historically been difficult to independently separate the motor housing 11 from the transmission mechanism housing 12. Therefore, a problem arises where, in the event of a malfunction in the motor 20 or the transmission mechanism 60, it is difficult to separate only the malfunctioning component, making replacement and repair difficult. In contrast, according to this embodiment, as described above, by constructing the motor housing 11 and the transmission mechanism housing 12 as two separate components, the motor housing 11 and the transmission mechanism housing 12 can be easily separated. Therefore, according to this embodiment, in the drive device 100 with a structure that moves oil O between the motor housing 11 and the transmission mechanism housing 12, the motor 20 and the transmission mechanism 60 can be easily separated independently. Consequently, in the event of a malfunction in the motor 20 or the transmission mechanism 60, only the malfunctioning component can be separated. Therefore, replacement and repair of the malfunctioning component are easier.

[0210] Furthermore, according to this embodiment, when viewed axially, the first opening 13e and the second opening 15h at least partially overlap each other. Therefore, oil O flowing from the motor housing 11 into the first opening 13e can easily flow through the second opening 15h into the transfer mechanism housing 12. Consequently, oil O can more easily return from the motor housing 11 to the transfer mechanism housing 12 via the first recovery path 93x.

[0211] Furthermore, according to this embodiment, the first opposing wall portion 13a and the second housing member 14 respectively hold bearings 71 and 72, which support the motor shaft 31 for rotation. The second opposing wall portion 15a and the fourth housing member 16 respectively hold bearings 73 and 74, which support the first gear shaft 63 for rotation. Therefore, by separating the motor housing 11 from the transmission mechanism housing 12, the unit including the motor housing 11 and the motor 20 can be appropriately separated from the unit including the transmission mechanism housing 12 and the transmission mechanism 60.

[0212] Furthermore, according to this embodiment, when viewed axially, the width of the first opening 13e in the direction intersecting the vertical direction expands downwards in the vertical direction. Similarly, when viewed axially, the width of the second opening 15h in the direction intersecting the vertical direction expands downwards in the vertical direction. Therefore, oil O stored in the lower part of the motor housing 11 can easily flow to the first opening 13e and the second opening 15h by gravity. Consequently, oil O can be more easily returned from the motor housing 11 to the transfer mechanism housing 12 via the first recovery path 93x.

[0213] Furthermore, according to this embodiment, the opening area of ​​the opening end 15w of the second opening 15h that opens inside the transfer mechanism housing 12 is larger than the opening area of ​​the opening end 13w of the first opening 13e that opens inside the motor housing 11. Therefore, blockage of oil O flowing from the motor housing 11 into the first opening 13e between the first opening 13e and the second opening 15h can be prevented. Consequently, oil O flowing into the first opening 13e can flow more appropriately into the interior of the transfer mechanism housing 12 via the second opening 15h. Therefore, oil O can be more easily returned from the motor housing 11 to the transfer mechanism housing 12 via the first recovery path 93x.

[0214] Furthermore, according to this embodiment, the first flow path 90 has a second recovery path 93y, which returns the oil O supplied to the motor 20 to the interior of the transfer mechanism housing 12. Therefore, in addition to the first recovery path 93x, the oil O supplied to the motor housing 11 can also be returned to the transfer mechanism housing 12 via the second recovery path 93y. This increases the amount of oil O returning from the motor housing 11 to the transfer mechanism housing 12. Furthermore, at least a portion of the second recovery path 93y is composed of an axially extending flow path portion 93h provided on the first housing member 13 and a flow path portion 93j provided on the second opposing wall portion 15a as a third opening. Therefore, the second recovery path 93y can be easily and appropriately configured to span the first housing member 13 and the third housing member 15.

[0215] Furthermore, according to this embodiment, the second recovery path 93y includes: a groove 93a provided on the inner circumferential surface of the motor housing 11 and extending axially; a second recovery path main body 93c located radially outward of the groove 93a and extending axially to connect with the interior of the transfer mechanism housing 12; and a connecting portion 93b connecting the groove 93a and the second recovery path main body 93c. Therefore, at least a portion of the oil O supplied to the motor housing 11 through the first supply flow path 91 and the second supply flow path 92 can flow from the groove 93a into the second recovery path 93y. Furthermore, the oil O flowing into the groove 93a can be transported to the transfer mechanism housing 12 via the connecting portion 93b and the second recovery path main body 93c. Thus, through the second recovery path 93y, the oil O in the motor housing 11 can be easily returned to the transfer mechanism housing 12. Furthermore, according to this embodiment, at least a portion of the second recovery path main body 93c is located radially outward of the second flow path 50. Therefore, the water W flowing in the second flow path 50 can easily cool the oil O flowing in the main body 93c of the second recovery path.

[0216] Furthermore, according to this embodiment, the connecting portion 93b connects the end of the groove portion 93a on the other side of the axial direction to the end of the second recovery path main body portion 93c on the other side of the axial direction. That is, the position where the groove portion 93a and the second recovery path main body portion 93c are connected by the connecting portion 93b is located axially further away from the transfer mechanism housing 12. Therefore, the flow distance of oil O from the connecting portion 93b into the second recovery path main body portion 93c and then into the transfer mechanism housing 12 can be extended. This extends the time for cooling the oil O flowing in the second recovery path main body portion 93c by the water W flowing in the second flow path 50. Therefore, the water W flowing in the second flow path 50 can appropriately cool the oil O flowing in the second recovery path main body portion 93c. Therefore, it is easier to supply the motor 20 with lower temperature oil O. This further improves the cooling efficiency of the motor 20.

[0217] Furthermore, according to this embodiment, the plurality of first circumferential flow path portions 52a include a first circumferential flow path portion 52c, which circumferentially crosses one axial side of the groove portion 93a. A connecting portion 93b is located between adjacent second circumferential flow path portions 52b in the circumferential direction. Thus, on the side opposite to the side where the connecting portion 93b is provided in the axial direction, the first circumferential flow path portion 52c crosses the groove portion 93a, allowing the connecting portion 93b to extend from a radially inner position to a radially outer position without interfering with the second flow path 50. Therefore, at least a portion of the second recovery path main body portion 93c can be positioned radially outer of the second flow path 50 without interfering with the second flow path 50.

[0218] Furthermore, according to this embodiment, the second supply flow path 92 has an inlet flow path portion 92a extending axially from the interior of the transfer mechanism housing 12. At least a portion of the inlet flow path portion 92a is located radially outside the second flow path 50. Therefore, the inlet flow path portion 92a can be configured close to the second flow path 50. As a result, the water W flowing within the second flow path 50 can easily cool the oil O passing through the inlet flow path portion 92a. Therefore, the temperature of the oil O supplied to the interior of the motor housing 11 through the second supply flow path 92 can be relatively low. Therefore, the motor 20 housed within the motor housing 11 can be cooled more appropriately by the oil O. Therefore, the cooling efficiency of the motor 20 can be further improved.

[0219] Furthermore, according to this embodiment, the inlet flow path 92a and the second recycling path 93y are arranged adjacent to each other in the circumferential direction. Therefore, the inlet flow path 92a and the second recycling path 93y can be arranged in a concentrated manner. As a result, the structural complexity of the outer casing 10 can be suppressed.

[0220] Furthermore, according to this embodiment, the second recovery path 93y and the second flow path 50 are respectively arranged to span the first housing member 13 and the second housing member 14. Therefore, the second recovery path 93y and the second flow path 50 can be increased axially. As a result, it is easy to increase the portion of the second recovery path 93y that is positioned close to the second flow path 50. Therefore, the water W flowing in the second flow path 50 can more easily cool the oil O flowing in the second recovery path 93y. In addition, by increasing the second flow path 50 axially, the range of the motor 20 that can be cooled by the water W flowing in the second flow path 50 can be expanded axially. As a result, the water W flowing in the second flow path 50 can easily cool the entire stator core 41 and the coil edge ends 42a, 42b protruding axially from the stator core 41. As a result, the cooling efficiency of the motor 20 can be further improved.

[0221] Furthermore, according to this embodiment, the first flow path 90, extending axially from the interior of the motor housing 11 to the interior of the transmission mechanism housing 12, has a second recovery path main body 93c. At least a portion of the second flow path 50 and the first flow path 90 overlap each other radially. Therefore, the oil O flowing in the second recovery path main body 93c can be easily cooled by the water W flowing in the second flow path 50. Consequently, the oil O in the first flow path 90 can be easily cooled by the water W in the second flow path 50 over a wide axial range in the first flow path 90.

[0222] Furthermore, according to this embodiment, the second flow path 50 has an inner portion 52k located between the first opening 13e and the second recovery path 93y, and an outer portion 52m located between the second opening 15h and the second recovery path 93y. Therefore, the water W flowing in the second flow path 50 can more easily cool the oil O flowing in the second recovery path 93y.

[0223] Furthermore, according to this embodiment, the first outer casing member 13 and the second outer casing member 14 are fixed to each other at a position radially inner to the second recovery path 93y and adjacent to the second flow path 50 in the circumferential direction. In this embodiment, the first outer casing member 13 and the second outer casing member 14 are fixed to each other at this position by a fourth bolt 10d screwed into the female threaded hole 13i. Thus, the first outer casing member 13 and the second outer casing member 14 can be fixed at a position close to both the second recovery path 93y and the second flow path 50. Therefore, the separation of the portions of the first outer casing member 13 and the second outer casing member 14 that constitute the second recovery path 93y from each other can be suppressed. Furthermore, the separation of the portions of the first outer casing member 13 and the second outer casing member 14 that constitute the second flow path 50 from each other can be suppressed. Thus, leakage of oil O from the second recovery path 93y and leakage of water W from the second flow path 50 can be suppressed. Furthermore, oil O leaking from the second recovery path 93y can be prevented from seeping into the second flow path 50 and mixing with water W. In addition, it can prevent water W leaking from the second flow path 50 from seeping into the second recovery path 93y and mixing with oil O.

[0224] For example, in the case where the housing 10 is composed of two different components constituting the motor housing 11 and two different components constituting the transmission mechanism housing 12, as in this embodiment, the motor housing 11 and the transmission mechanism housing 12 are separated. In this case, conventionally, structures for lubricating the bearings are provided in both the motor housing 11 and the transmission mechanism housing 12. Therefore, due to the increased complexity of the housing 10's structure or the use of more expensive bearings that do not require lubrication, there is a problem of increased manufacturing costs for the drive unit 100. More expensive bearings that do not require lubrication refer to, for example, bearings provided with semi-solid grease.

[0225] In contrast, according to this embodiment, the housing 10 has an oil supply path 95 extending axially through the second opposing wall portion 15a from the interior of the transmission mechanism housing 12. The oil supply path 95 has a supply port 13h that supplies oil O to the bearing 72 held in the first opposing wall portion 13a of the motor housing 11. The supply port 13h is located above the central axis J1. Therefore, the oil O discharged from the supply port 13h can fall by gravity and be supplied to the bearing 72 in the motor housing 11, which supports the rotor 30 that can rotate about the central axis J1. In other words, a portion of the oil O inside the transmission mechanism housing 12 can be supplied to the bearing 72 in the motor housing 11 via the oil supply path 95. Using this bearing lubrication structure in the transmission mechanism housing 12, the bearing 72 in the motor housing 11 can be lubricated. In other words, the drive unit 100 is configured such that the motor housing 11 can be separated from the transmission mechanism housing 12, and the bearing 72 disposed on the motor housing 11 can be lubricated using the oil O inside the transmission mechanism housing 12. Therefore, the structural complexity of the housing 10 can be suppressed, and it is not necessary to use a bearing 72 that does not require lubrication. Therefore, the increase in manufacturing cost of the drive unit 100 can be suppressed.

[0226] Furthermore, according to this embodiment, the first bearing holding portion 13c is provided on the surface on the other side of the first opposing wall portion 13a along the axial direction. The oil supply path 95 passes through the first opposing wall portion 13a along the axial direction and extends into the interior of the motor housing 11. The supply port 13h opens inside the motor housing 11. Therefore, even when the bearing 72 held in the first bearing holding portion 13c is located inside the motor housing 11, oil O can be supplied to the bearing 72 through the oil supply path 95.

[0227] Furthermore, according to this embodiment, the first bearing holding portion 13c has a through portion 13f that radially penetrates the first bearing holding portion 13c. A supply port 13h opens inside the through portion 13f. Therefore, oil O discharged from the supply port 13h can be easily supplied to the interior of the first bearing holding portion 13c through the through portion 13f. This makes it easier to supply oil O to the bearing 72.

[0228] Furthermore, according to this embodiment, the oil supply path 95 includes: a first hole 13g extending axially through the first opposing wall portion 13a; a second hole 15g extending axially through the second opposing wall portion 15a; and a first groove 17 located between the first opposing wall portion 13a and the second opposing wall portion 15a in the axial direction, connecting the first opposing wall portion 13a and the second opposing wall portion 15a. The first groove 17 is connected to a portion of the surface of the first opposing wall portion 13a on one axial side located below the first hole 13g and a portion of the surface of the second opposing wall portion 15a on the other axial side located below the second hole 15g. Therefore, oil O in the transmission mechanism housing 12 can be supplied to the motor housing 11 sequentially via the second hole 15g, the first groove 17, and the first hole 13g. As a result, oil O in the transmission mechanism housing 12 can be supplied to the bearing 72 in the motor housing 11 more appropriately.

[0229] Furthermore, according to this embodiment, the oil supply path 95 has a second groove 18 located inside the transmission mechanism housing 12. The second groove 18 is connected to the portion of the second opposing wall 15a located below the second hole 15g on one axial side. Therefore, for example, a portion of the oil O that is thrown up by the gear ring 62a and scattered into the transmission mechanism housing 12 can be received by the second groove 18. In addition, at least a portion of the oil O received by the second groove 18 can flow into the second hole 15g. As a result, the oil O in the transmission mechanism housing 12 can be supplied more appropriately to the bearing 72 in the motor housing 11 via the second hole 15g, the first groove 17, and the first hole 13g in sequence.

[0230] Furthermore, according to this embodiment, the second opposing wall portion 15a has a second opening portion 15h, which connects the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a to the interior of the transfer mechanism housing 12. Therefore, for example, oil O leaking from the first groove portion 17 can be returned to the transfer mechanism housing 12 via the second opening portion 15h. This prevents oil O from accumulating in the space S.

[0231] Furthermore, according to this embodiment, the first opposing wall portion 13a has a first opening portion 13e, which connects the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a to the interior of the motor housing 11. Therefore, the interior of the motor housing 11 can be connected to the interior of the transmission mechanism housing 12 via the first opening portion 13e, the space S, and the second opening portion 15e. This allows the aforementioned through hole 19a to be formed, and at least a portion of the oil O supplied to the motor housing 11 to be returned to the transmission mechanism housing 12.

[0232] This invention is not limited to the embodiments described above, and other structures and methods can be employed within the scope of the technical concept of this invention. The first flow path can be of any structure as long as it has a supply path and a first recycling path. In the above embodiments, the supply path is configured to include a first supply flow path 91 and a second supply flow path 92, but this is not a limitation. Alternatively, only either the first supply flow path 91 or the second supply flow path 92 may be provided as the supply path.

[0233] The first recovery path that returns the first fluid supplied to the motor to the housing of the transmission mechanism can be of any structure, provided that at least a portion of it consists of the first opening and the second opening. When viewed axially, the first and second openings can either be entirely overlapping each other or entirely non-overlapping. The shape and size of the first opening are not particularly limited. The shape and size of the second opening are not particularly limited.

[0234] The second recovery path, which returns the first fluid supplied to the motor to the housing of the transfer mechanism, can have any structure. If the motor housing has a first housing member and a second housing member, the second recovery path may be provided only in the first housing member. The shape and size of the groove constituting the second recovery path, the shape and size of the connecting portion constituting the second recovery path, and the shape and size of the main body of the second recovery path are not particularly limited. Alternatively, the second recovery path may not be provided.

[0235] The second flow path can also be of any shape. The second flow path can be composed solely of the first outer shell member, or solely of the first and second outer shell members. The first circumferential flow path can also be configured not to cross the first and third outer shell members. The second circumferential flow path can also be configured not to cross the first and second outer shell members. The number of axial flow paths is not particularly limited as long as there are two or more. The number of first and second circumferential flow paths is not particularly limited as long as there is one or more.

[0236] When the first circumferential flow path is composed of a first outer shell member and a third outer shell member, the third outer shell member may not have the first recess. In this case, the first circumferential flow path can also be constructed by closing a first space in the first outer shell member located on one axial side of the first partition wall with a surface on the other axial side of the third outer shell member. When the second circumferential flow path is composed of a first outer shell member and a second outer shell member, the second outer shell member may not have the second recess. In this case, the second circumferential flow path can also be constructed by closing a second space in the first outer shell member located on the other axial side of the second partition wall with a surface on one axial side of the second outer shell member.

[0237] The types of the first fluid flowing within the first flow path and the types of the second fluid flowing within the second flow path are not particularly limited. The first and second fluids can also be the same type of fluid. The first fluid can be either an insulating liquid or water. If the first fluid is water, insulation treatment can be applied to the surface of the stator. The second fluid can also be oil. Alternatively, a second flow path may not be provided.

[0238] The oil supply path extending axially through the second opposing wall portion from the inside of the transmission mechanism housing can be of any structure, as long as it has a supply port located above the central axis and supplying oil to the bearing. If the bearing retaining portion of the first opposing wall portion of the motor housing is located on the axial side of the first opposing wall portion, i.e., the side of the first opposing wall portion facing the transmission mechanism housing, the oil supply path may only penetrate the second opposing wall portion and not the first opposing wall portion. In this case, for example, the supply port of the oil supply path is a spatial opening between the first and second opposing walls portions. The oil supply path may also lack at least one of the first hole portion, second hole portion, first groove portion, and second groove portion. The oil supply path may also be constructed of a tubular component such as a pipe. Alternatively, an oil supply path may not be provided at all.

[0239] The application of the drive device used in this invention is not particularly limited. For example, the drive device can be installed in a vehicle for purposes other than rotating the axle, or in equipment outside of a vehicle. The orientation of the drive device during use is not particularly limited. The central axis of the motor can be inclined relative to a horizontal direction orthogonal to the vertical direction, or it can extend along the vertical direction. The structures described above in this specification can be appropriately combined without contradiction.

Claims

1. A driving device, wherein, include: A motor having a rotor and a stator, the rotor being rotatable about a central axis, and the stator covering the radially outer side of the rotor; A transmission mechanism, which is connected to the motor; The housing has a motor housing and a transmission mechanism housing, the motor housing internally housing the motor, and the transmission mechanism housing fixed to one axial side of the motor housing internally housing the transmission mechanism and the first fluid; as well as A first flow path, wherein the first flow path allows the first fluid to flow within it. The first flow path has: A supply path that supplies the first fluid, housed inside the housing of the transmission mechanism, to the motor; and A first recovery path is provided, which returns the first fluid supplied to the motor to the interior of the transfer mechanism housing. The motor housing has: A first outer casing component is fixed to the outer casing of the transmission mechanism; as well as A second housing component is fixed to the other side of the first housing component along its axial direction. The housing of the transmission mechanism has: A third outer casing component, wherein the third outer casing component is fixed to the first outer casing component; as well as A fourth housing component is fixed to one axial side of the third housing component. The first housing component has: The first opposing wall portion is axially facing the third outer shell component; as well as A bearing retaining portion is disposed on the first opposing wall portion and retains the bearing that supports the rotor for rotation. The third outer casing component has a second opposing wall portion, which faces the first opposing wall portion axially. The first opposing wall portion has a first opening, which opens both inside and outside the motor housing. The second opposing wall portion has a second opening, which opens both inside and outside the housing of the transfer mechanism. At least a portion of the first recycling path is formed by the first opening and the second opening. The first flow path has a second recovery path that returns the first fluid supplied to the motor to the interior of the transfer mechanism housing. The first housing component has a flow path portion extending axially. The second opposing wall portion has a third opening, which opens inside the housing of the transfer mechanism. At least a portion of the second recycling path is formed by the flow path portion and the third opening. The drive device includes a second flow path through which a second fluid flows. The second flow path has: The portion located between the first opening and the second recycling path; as well as The portion located between the second opening and the second recycling path.

2. The driving device as claimed in claim 1, wherein, When viewed along the axial direction, the first opening and the second opening at least partially overlap each other.

3. The driving device as claimed in claim 1, wherein, The rotor has a motor shaft extending axially. The transmission mechanism has a gear shaft that is axially connected to the motor shaft. The first opposing wall portion and the second housing component each hold a bearing that supports the motor shaft for rotation. The second opposing wall portion and the fourth housing component each have a bearing that supports the gear shaft so that it can rotate.

4. The driving device as claimed in claim 1, wherein, The bearing retaining portion is located on the other side of the first opposing wall portion along its axial direction.

5. The driving device as claimed in claim 1, wherein, When viewed along the axial direction, the width of the first opening in the direction intersecting the vertical direction expands downwards in the vertical direction. When viewed along the axial direction, the width of the second opening in the direction intersecting the vertical direction expands on the lower side in the vertical direction.

6. The driving device as claimed in claim 1, wherein, The rotor has a motor shaft extending axially. The motor shaft is a hollow shaft with openings on both sides in the axial direction. The interior of the motor shaft forms part of the supply path. The first fluid is supplied into the interior of the motor shaft from both axial sides.

7. The driving device according to any one of claims 1 to 6, wherein, The second housing component is fixed to the other side of the first housing component by a plurality of first bolts. The third outer shell component is fixed to the first outer shell component by a plurality of second bolts. The fourth housing component is fixed to one axial side of the third housing component by a plurality of third bolts. The plurality of first bolts that fix the first outer shell component and the second outer shell component pass through the plurality of through holes provided in the second outer shell component from the other side of the axial direction, and are respectively fixed in the plurality of bolt holes provided in the first outer shell component. The plurality of second bolts that fix the first outer shell component and the third outer shell component pass through the plurality of through holes provided in the first outer shell component from the other side of the axial direction, and are respectively fixed in the plurality of bolt holes provided in the third outer shell component. The plurality of third bolts that fix the third housing component and the fourth housing component pass through the plurality of through holes provided in the fourth housing component from one axial side, and are respectively fixed in the plurality of bolt holes provided in the third housing component.

8. The drive device according to any one of claims 1 to 6, wherein, The second recovery path has a portion located upstream of the flow path portion that guides the first fluid from a position on one side of the stator core relative to the stator towards a position on the other side of the stator core relative to the stator.

9. The driving device according to any one of claims 1 to 6, wherein, The second recycling path has: The third opening; The flow path portion is disposed on the first housing member; as well as The portion connected to the flow path portion and located on the axial side opposite to the stator core of the stator, within the opening of the motor housing.

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