Vehicle drive systems

Abstract

Disclosed is a vehicle drive device comprising a case, a power transmission mechanism, an oil pump, and an oil passage structure. The case includes: a case member that has, at an axial end, a first mating surface, and a second mating surface on the radially inside of the first mating surface when viewed in the axial direction of a rotating shaft member; and a cover member that has a third mating surface which is aligned with the first mating surface in the axial direction, and a fourth mating surface which is aligned with the second mating surface in the axial direction, and that is coupled to the case member through coupling between the first mating surface and the third mating surface. The oil passage structure includes an oil passage between the discharge side of the oil pump and an object to be supplied with the oil. The oil passage is formed so as to be surrounded by at least one of the second mating surface and the fourth mating surface when viewed in the axial direction, and has a groove recessed toward at least one of the mating surfaces in the axial direction.

Description

Technical Field

[0001] The present disclosure relates to a vehicle drive device.

Background Art

[0002] A structure is known in which oil in an accommodation chamber of a case that houses a power transmission mechanism is guided to an oil cooler through an oil passage (inside a case wall portion) formed in the case by machining.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when forming an oil passage in a case by machining, although no separate pipe material is required, since the machining holes by mechanical machining (drill) are exposed to the outside, a plug for closing the oil passage is required. In this regard, in the prior art as described above, since the entire oil passage for guiding oil from a pump to an oil cooler is formed by an oil passage formed in a case by machining, there is a problem that it is likely to cause an increase in the number of plugs and the assembly man-hours. In general, since machining holes by mechanical machining are formed linearly, when forming an oil passage of a path including a bent portion, the number of plugs increases according to the increase in the number of bent portions.

[0005] Therefore, on one aspect, an object of the present disclosure is to reduce the number of necessary plugs in an oil passage included in an oil supply system from an oil pump to a supply object.

Means for Solving the Problems

[0006] On one aspect, a case that forms an accommodation chamber through which oil flows, A power transmission mechanism including a rotating shaft member, which is arranged in the aforementioned storage chamber and capable of transmitting power from a power source to the wheels, An oil pump that sucks up and discharges oil from the aforementioned containment chamber, The case comprises an oil passage structure formed in at least a portion thereof, The aforementioned case is, A case member having a first mating surface at its axial end and a second mating surface located radially inward from the first mating surface when viewed in the axial direction of the rotating shaft member, A cover member having a third mating surface aligned axially with the first mating surface and a fourth mating surface aligned axially with the second mating surface, and being coupled to the case member via a connection between the first mating surface and the third mating surface, The oil passage structure includes an oil passage between the discharge side of the oil pump and the object to which the oil is supplied. The oil passage is formed in such a manner that it is surrounded in the axial direction by at least one of the second mating surface and the fourth mating surface, and has a groove that is recessed in the axial direction with respect to at least one of the mating surfaces, in a vehicle drive device. [Effects of the Invention]

[0007] In one respect, this disclosure makes it possible to reduce the number of plugs required in the oil passages included in the oil supply system from the oil pump to the object being supplied. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic top view diagram showing the mounting configuration of the vehicle's drive system. [Figure 2] This is a schematic cross-sectional view of the main components of a vehicle's drive system. [Figure 2A] This is a skeleton diagram showing a vehicle drive system. [Figure 2B] This diagram schematically shows the oil flow in a vehicle drive system according to this embodiment. [Figure 3] This diagram schematically shows a portion of the motor case as viewed from the second axial side A2. [Figure 4] This diagram schematically shows a part of the gear case member as viewed from the first axial side A1. [Figure 5] This is a cross-sectional view of a portion of a gear case component when cut by a plane parallel to the axial direction. [Figure 6] This is a perspective view of the gear case member as seen from the second axial side A2. [Figure 7] This diagram schematically shows the oil flow in a vehicle drive system, along with a cross-sectional view of the main parts of the vehicle drive system according to Example 2. [Modes for carrying out the invention]

[0009] The following describes each embodiment in detail with reference to the attached drawings. Note that the dimensional ratios in the drawings are merely examples and are not exhaustive. Furthermore, shapes and other details in the drawings may be partially exaggerated for illustrative purposes. Also, for clarity, in some cases, only a portion of parts with the same attribute are assigned reference numerals in the drawings.

[0010] In the following description, the orientation of each component refers to its orientation when assembled to the vehicle drive unit 100. Furthermore, the terms related to the dimensions, orientation, and position of each component are concepts that include variations due to manufacturing tolerances.

[0011] In this specification, “driving connection” refers to a state in which two rotating elements are connected in a manner that enables the transmission of driving force (synonymous with torque), and includes a state in which the two rotating elements are connected so as to rotate as a whole, or a state in which the two rotating elements are connected in a manner that enables the transmission of driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed (e.g., shafts, gear mechanisms, belts, chains, etc.). In addition, the transmission members may include engagement devices that selectively transmit rotation and driving force (e.g., friction engagement devices, meshing engagement devices, etc.).

[0012] In this specification, the term "rotating electric machine" is used to encompass the concept of motors, generators, and motor-generators that perform both motor and generator functions as needed. Furthermore, in this specification, with regard to the arrangement of two members, "overlapping in a specific viewing direction" means that when a virtual line parallel to the line of sight is moved in each direction perpendicular to that virtual line, there exists at least a portion of the region where the virtual line intersects both members. Furthermore, in this specification, with regard to the arrangement of two members, "overlapping arrangement regions in a specific direction" means that at least a portion of the arrangement region of one member in a specific direction is contained within the arrangement region of the other member in a specific direction.

[0013] Figure 1 is a schematic top view showing the mounting state of the vehicle drive unit 100 in the vehicle VC. Figure 2 is a cross-sectional view of the main part of the vehicle drive unit 100. Figure 2A is a skeleton view showing the vehicle drive unit 100. Figure 2B is a schematic diagram showing the oil flow in the vehicle drive unit 100 according to this embodiment. Figure 3 is a schematic diagram showing a part of the motor case 250 viewed from the second axial side A2. Figure 4 is a schematic diagram showing a part of the gear case member 254 (the part facing the part of the motor case 250 in Figure 3 in the axial direction) viewed from the first axial side A1. Figure 5 is a cross-sectional view of a part of the gear case member 254 when cut by a plane parallel to the axial direction. Figure 6 is a perspective view of the gear case member 254 viewed from the second axial side A2. Note that the oil cooler 90 is not shown in Figures 2 and 6.

[0014] In FIG. 2, an axial direction A is defined, and in FIGS. 3 and 4, a first direction X and a second direction Y are defined. The first direction X, the second direction Y, and the axial direction A are three mutually orthogonal axial directions, and the second direction Y is assumed to have a vertical component. In this case, the first direction X corresponds to the longitudinal direction of the vehicle. The second direction Y may be parallel to the gravitational direction (vertical direction) or inclined in the mounting state of the vehicle drive device 100 in the vehicle VC. For example, the vehicle drive device 100 may be mounted on the vehicle VC in a direction where the first side Y1 in the second direction is the upper side and the second side Y2 in the second direction is the lower side. Also, the vehicle drive device 100 may be mounted on the vehicle VC in a direction where the first side X1 in the first direction is the front side (the front side in the longitudinal direction of the vehicle) and the second side X2 in the first direction is the rear side (the rear side in the longitudinal direction of the vehicle). As shown in FIG. 1, the vehicle drive device 100 may be mounted on the front side of the central portion in the longitudinal direction of the vehicle VC or on the rear side of the central portion in the longitudinal direction of the vehicle VC. When the vehicle drive device 100 is mounted on the rear side of the central portion in the longitudinal direction of the vehicle VC in this way, the pair of wheels W driven by the vehicle drive device 100 may be, for example, a pair of left and right rear wheels.

[0015] When the vehicle VC includes a pair of left and right front wheels and a pair of left and right rear wheels, a non-driven side (in the example shown in FIG. 1, the pair of left and right rear wheels) of the pair of left and right front wheels and the pair of left and right rear wheels by the vehicle drive device 100 may be configured to be driven by a drive device other than the vehicle drive device 100. The drive device other than the vehicle drive device 100 is, for example, a drive device configured to transmit the output torque of an internal combustion engine to a pair of wheels to be driven, a drive device configured to transmit the output torque of a rotating electric machine (a rotating electric machine different from the rotating electric machine 1 included in the vehicle drive device 100) to a pair of wheels to be driven, or a drive device configured to transmit the output torques of both an internal combustion engine and a rotating electric machine (a rotating electric machine different from the rotating electric machine 1 included in the vehicle drive device 100) to a pair of wheels to be driven. The drive device other than the vehicle drive device 100 may be a drive device having the same configuration as the vehicle drive device 100.

[0016] In this embodiment, as schematically shown in FIG. 2A, the vehicle drive device 100 includes a rotating electric machine 1, a pair of output members 6 respectively drivingly connected to a pair of wheels W, and a transmission mechanism 3 that transmits driving force between the rotating electric machine 1 and the pair of output members 6. The vehicle drive device 100 further includes a case 2 that houses the rotating electric machine 1. The case 2 also houses the pair of output members 6 and the transmission mechanism 3.

[0017] One of the pair of output members 6, the first output member 61, is drivingly connected to one of the pair of wheels W, the first wheel W1, and the other of the pair of output members 6, the second output member 62, is drivingly connected to the other of the pair of wheels W, the second wheel W2. As shown in FIG. 1, a vehicle VC on which the vehicle drive device 100 is mounted includes a first drive shaft 63 that rotates integrally with the first wheel W1 and a second drive shaft 64 that rotates integrally with the second wheel W2. The first drive shaft 63 is connected to the first wheel W1 via, for example, a constant velocity joint, and the second drive shaft 64 is connected to the second wheel W2 via, for example, a constant velocity joint. Then, the first output member 61 is connected to the first drive shaft 63 so as to rotate integrally with the first drive shaft 63, and the second output member 62 is connected to the second drive shaft 64 so as to rotate integrally with the second drive shaft 64.

[0018] The vehicle drive device 100 transmits the output torque of the rotating electric machine 1 to the pair of wheels W via the pair of output members 6 to cause the vehicle VC on which the vehicle drive device 100 is mounted to travel. That is, the rotating electric machine 1 is a driving force source for the pair of wheels W. The pair of wheels W are a pair of left and right wheels in the vehicle VC (for example, a pair of left and right front wheels or a pair of left and right rear wheels). The rotating electric machine 1 may be, for example, an AC rotating electric machine driven by three-phase AC. The rotating electric machine 1 is electrically connected to a battery BA (see FIG. 1) (including a power storage device such as a capacitor) via an inverter device (not shown) that performs power conversion between DC power and AC power, receives power supply from the battery BA to perform power running, or supplies the power generated by the inertial force of the vehicle VC or the like to the power storage device for power storage.

[0019] As shown in Figure 2, the rotating electric machine 1 and the pair of output members 6 are arranged on two parallel axes (specifically, a first axis C1 and a second axis C2). Specifically, the rotating electric machine 1 is positioned on the first axis C1, and the pair of output members 6 are positioned on a second axis C2, which is different from the first axis C1. The first axis C1 and the second axis C2 are axes (virtual axes) that are positioned parallel to each other. The transmission mechanism 3 is provided with an output gear (ring gear) 30 that is driven and connected to at least one of the pair of output members 6, coaxially with the pair of output members 6 (i.e., on the second axis C2).

[0020] As shown in Figure 1, the vehicle drive unit 100 is mounted on the vehicle VC with its axial direction A aligned with the left-right direction of the vehicle. The axial direction A is parallel to the first axis C1 and the second axis C2, in other words, it is the common axial direction between the first axis C1 and the second axis C2. That is, the axial direction A is the direction in which the rotation axis of the rotating electric machine 1 extends, and also the direction in which the rotation axes of the pair of output members 6 extend. Here, one side of the axial direction A is called the axial first side A1, and the other side of the axial direction A (opposite to the axial first side A1 in the axial direction A) is called the axial second side A2. The axial first side A1 is the side in the axial direction A on which the rotating electric machine 1 is positioned relative to the transmission mechanism 3. As shown in Figure 2A, the first output member 61 is the output member 6 of the pair of output members 6 that is positioned on the axial first side A1, and the second output member 62 is the output member 6 of the pair of output members 6 that is positioned on the axial second side A2.

[0021] As shown in Figure 1, the vehicle drive unit 100 may be mounted on the vehicle VC with the axial first side A1 on the left side of the vehicle and the axial second side A2 on the right side of the vehicle. In this case, the first wheel W1 to which the first output member 61 is driven is the left wheel, and the second wheel W2 to which the second output member 62 is driven is the right wheel. Figure 1 assumes that the vehicle drive unit 100 is a front-wheel drive system that drives a pair of left and right front wheels. Therefore, in the example shown in Figure 1, the first wheel W1 is the left front wheel, and the second wheel W2 is the right front wheel.

[0022] As shown in Figure 2, the rotating electric machine 1 comprises a rotor 10 and a stator 11. The stator 11 is fixed to the case 2, and the rotor 10 is supported by the case 2 so as to be rotatable relative to the stator 11. The rotating electric machine 1 may be an inner rotor type, in which case the rotor 10 may be positioned radially inward relative to the stator 11, and overlapping with the stator 11 in a radial view along the radial direction. Here, the radial direction is the radial direction with respect to the first axis C1, in other words, the radial direction with respect to the rotation axis of the rotating electric machine 1.

[0023] The stator 11 comprises a stator core 12 and coil end portions 13 that protrude from the stator core 12 in the axial direction A. A coil is wound around the stator core 12, and the portion of the coil that protrudes from the stator core 12 in the axial direction A forms the coil end portions 13. The coil end portions 13 are formed on both sides of the stator core 12 in the axial direction A.

[0024] The transmission mechanism 3 includes a counter gear mechanism 4 in the power transmission path between the rotating electric machine 1 and the output gear 30. In a modified example, a reduction mechanism using planetary gears may be used instead of the counter gear mechanism 4. In this case, a two-axis configuration may be realized in which the third axis C3 is eliminated, instead of the three-axis configuration.

[0025] In this embodiment, the counter gear mechanism 4 is positioned on an offset axis (i.e., a third axis C3) relative to the input member 16 which is coaxial with the rotating electric machine 1. The input member 16 is connected to the rotor 10 so as to rotate integrally with the rotor 10. In the example shown in Figure 2, the vehicle drive unit 100 includes a rotor shaft 15 to which the rotor 10 is fixed, and the input member 16 is connected to the rotor shaft 15 so as to rotate integrally with the rotor shaft 15. Specifically, the axial first side A1 portion of the input member 16 may be connected (in this case, by spline connection) to the axial second side A2 portion of the rotor shaft 15. In contrast to this configuration, the rotor shaft 15 of the vehicle drive unit 100 can also be formed integrally with the input member 16 as a single piece.

[0026] The counter gear mechanism 4 includes a counter shaft 41, a first counter gear 42, and a second counter gear 43.

[0027] The counter shaft 41 is a rotating shaft member that rotates around the third shaft C3. The third shaft C3 extends parallel to the first shaft C1. The first counter gear 42 is an input element of the counter gear mechanism 4. The first counter gear 42 meshes with the input gear 17 of the input member 16. The first counter gear 42 is connected to the counter shaft 41 so as to rotate integrally with the counter shaft 41.

[0028] The second counter gear 43 is the output element of the counter gear mechanism 4. In this embodiment, as an example, the second counter gear 43 is formed to have a smaller diameter than the first counter gear 42. The second counter gear 43 is mounted on the counter shaft 41 so as to rotate integrally with the counter shaft 41.

[0029] The transmission mechanism 3 includes a differential gear mechanism 5 in the power transmission path between the output gear 30 and the wheel W. The differential gear mechanism 5 is positioned on the second shaft C2, which serves as its rotation axis. The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 to a pair of output members 6. The differential gear mechanism 5 may be positioned coaxially with the pair of output members 6 (i.e., on the second shaft C2). The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 to the output gear 30 to the pair of output members 6. That is, the output gear 30 is driven and connected to both of the pair of output members 6 via the differential gear mechanism 5. The differential gear mechanism 5 may be a bevel gear type differential gear mechanism, and the output gear 30 may be connected to the differential case portion 50 of the differential gear mechanism 5 so as to rotate integrally with the differential case portion 50.

[0030] Now, with reference to Figure 2, the configuration of Case 2 will be explained further.

[0031] Case 2 may be formed from, for example, aluminum. Case 2 can be formed by casting or the like. Case 2 includes a motor case 250, a cover member 252, and a gear case member 254.

[0032] The motor case 250 forms a motor housing chamber SP1 that houses the rotating electric machine 1. The motor housing chamber SP1 may be an oil-tight space containing oil for cooling and / or lubricating the rotating electric machine 1 (and / or the transmission mechanism 3). The motor case 250 has a peripheral wall portion 2501 that surrounds the radially outer side of the rotating electric machine 1. The motor case 250 may be realized by joining multiple members together.

[0033] In the example shown in Figure 2, the motor case 250 has a partition wall 26 that separates the motor housing chamber SP1 and the gear housing chamber SP2 in the axial direction A. The partition wall 26 faces the bottom portion 2521 (described later) of the cover member 252 in the axial direction A.

[0034] A bearing support portion 2504, etc., for supporting the bearing 241 is formed on the axial second side A2 of the partition wall portion 26. A bearing support portion 2534 for supporting the bearing 243 is also formed on the axial second side A2 of the partition wall portion 26. The bearing support portion 2534 is formed concentrically with respect to the third shaft C3. As shown in Figure 2, the bearing 243 is provided on the radially outer side of the end of the axial first side A1 of the counter shaft 41. Specifically, the radially outer side of the outer race of the bearing 243 is supported by the bearing support portion 2534, and the radially inner side of the inner race is supported by the outer circumferential surface of the counter shaft 41. Oil may be supplied to the bearing 243 by its own weight, flowing along the partition wall portion 26, as shown by arrow R25 in Figure 2B.

[0035] The cover member 252 is coupled to the first axial side A1 of the motor case 250. The cover member 252 is in the form of a cover that covers the first axial side A1 of the motor housing chamber SP1. In this case, the cover member 252 may cover the opening of the first axial side A1 of the motor case 250 completely or substantially completely. A portion of the first axial side A1 of the motor housing chamber SP1 may be formed by the cover member 252.

[0036] The cover member 252 is provided with a bearing 240 that rotatably supports the rotor 10. That is, the cover member 252 has a bearing support portion 2524 that supports the bearing 240.

[0037] As shown in Figure 2, bearing 240 may be provided on the radially inner side of the first axial side A1 end of the rotor shaft 15. The radially outer side of bearing 240 may be supported by the inner circumferential surface of the rotor shaft 15, and the radially inner side of the inner race may be supported by the cover member 252. As shown in Figure 2, bearing 241 may be provided on the radially outer side of the second axial side A2 end of the rotor shaft 15. The radially outer side of bearing 241 may be supported by the partition wall 26, and the radially inner side of the inner race may be supported by the outer circumferential surface of the rotor shaft 15.

[0038] In the example shown in Figure 2, the cover member 252 includes a circular bottom portion 2521 centered on the first axis C1 and a peripheral wall portion 2522 projecting from the outer peripheral edge of the bottom portion 2521 toward the second axial side A2, with the end face of the peripheral wall portion 2522 toward the second axial side A2 being connected to the motor case 250. A cylindrical bearing support portion 2524 is formed in the central part of the second axial side A2 of the bottom portion 2521 (the portion centered on the first axis C1), projecting toward the second axial side A2. The bearing support portion 2524 is formed concentrically with respect to the first axis C1.

[0039] The gear case member 254 forms a gear housing chamber SP2 that houses the transmission mechanism 3. The gear housing chamber SP2 may be an oil-tight space communicating with the motor housing chamber SP1. The gear case member 254 is coupled to the motor case 250 on the second axial side A2. In this embodiment, the gear case member 254 is coupled to the motor case 250 at the coupling portion 2502 such that the mating surface 2548 abuts against the mating surface 2508 on the motor case 250 in the axial direction A. The gear case member 254 has a peripheral wall portion 2542 that surrounds the radially outer side of the transmission mechanism 3 and is in the form of a cover that covers the second axial side A2 of the gear housing chamber SP2. The end face of the peripheral wall portion 2542 on the first axial side A1 forms a mating surface 2548. The mating surface 2548 may extend in the same plane over its entire circumference, similar to the mating surface 2508 on the motor case 250. The gear case member 254 may be realized by joining multiple members. Furthermore, a portion of the axial first side A1 of the gear housing chamber SP2 may be formed by the motor case 250.

[0040] Next, the oil passage structure in this embodiment will be described with reference to Figures 2B and 3 to 6. In the following, unless otherwise specified, the motor housing chamber SP1 and the gear housing chamber SP2 will simply be referred to as the housing chamber SP. Figure 2B schematically shows the oil accumulating at the bottom of the housing chamber SP in a hatched area. Also in Figure 2B, the oil flow is schematically shown by arrows R300, etc., and the oil passages 81 etc. that realize this flow are schematically shown by corresponding arrows R300, etc.

[0041] In this embodiment, an oil cooler 90 is provided on the gear case member 254. The details of the structure of the oil cooler 90 are arbitrary. Cooling water is supplied to the oil cooler 90 as schematically shown by the arrow R200 in Figure 2B. The cooling water may be circulated by a water pump (not shown) via a radiator (not shown). Oil from the storage chamber SP of case 2 is supplied to the oil cooler 90. As a result, the heat from the oil in the storage chamber SP is transferred to the cooling water, and the oil in the storage chamber SP of case 2 is cooled.

[0042] Specifically, as shown in Figure 2B, the oil accumulating at the bottom of the containment chamber SP is drawn into the intake port of the electric oil pump 82 via the strainer 80 and oil passage 81 (see arrow R300). The oil discharged by the electric oil pump 82 is supplied to the oil cooler 90 via the oil passage 84 (see arrows R302 and R303). The oil is then cooled by the cooling water as described above by passing through the oil cooler 90 (arrow R304). The cooled oil may be supplied to the axial oil passage 15a of the rotor shaft 15 of the rotating electric machine 1 via the oil passage 86 (arrows R306, R308). In the example shown in Figure 2B, a catch tank 920 is provided for accumulating the oil (arrow R20) scraped up by the output gear 30. In this case, the oil from the catch tank 920 may be used to lubricate the counter gear mechanism 4, etc. (see arrow R21, etc.). R21, R22, and R23 represent the oil flow and oil passages that guide oil to the bearing 240.

[0043] In this embodiment, the oil passage 84 from the electric oil pump 82 to the oil cooler 90 includes an oil passage formed on the mating surface between the gear case member 254 and the motor case 250 (hereinafter also referred to as the "matting surface oil passage 840").

[0044] As shown in Figures 3 and 4, the mating surface oil passage 840 is formed by a groove 25090 related to the mating surface 2509 on the motor case 250 side and a groove 25490 related to the mating surface 2549 on the gear case member 254 side.

[0045] Specifically, the gear case member 254 has a protruding ridge 2547 that extends around the first axis C1 while projecting toward the first axial side A1, on the side closer to the first axis C1 than the mating surface 2548 when viewed in the axial direction A. The end face of the protruding ridge 2547 on the first axial side A1 extends in the same plane as the mating surface 2548, forming the mating surface 2549 on the gear case member 254 side. The protruding ridge 2547 has a groove 25490 corresponding to the mating surface 2549. The groove 25490 is recessed in the axial direction A toward the second axial side A2, in such a manner that it is surrounded by the mating surface 2549 in all directions intersecting the axial direction A (see also Figure 5). In this embodiment, the groove 25490 is surrounded by the mating surface 2549 in all directions intersecting the axial direction A, but it may also be partially surrounded by leaving some directions open (for example, the side connected to another oil passage).

[0046] Similarly, the motor case 250 has a protruding ridge 2507 that extends around the first axis C1 while projecting toward the second axial side A2, on the side closer to the first axis C1 than the mating surface 2508 when viewed in the axial direction A. The end face of the protruding ridge 2507 on the second axial side A2 extends in the same plane as the mating surface 2508, forming the mating surface 2509 on the motor case 250 side. The protruding ridge 2507 has a groove 25090 corresponding to the mating surface 2509. The groove 25090 is recessed in the axial direction A toward the first axial side A1, in such a manner that it is surrounded by the mating surface 2509 in all directions intersecting the axial direction A. In this embodiment, the groove 25090 is surrounded by the mating surface 2509 in all directions intersecting the axial direction A, but it may be partially surrounded by openings in some directions (for example, the side connected to other oil passages).

[0047] The mating surface 2549 on the gear case member 254 side and the mating surface 2509 on the motor case 250 side have substantially the same shape when viewed in the axial direction A, and the grooves 25490 and 25090 also have substantially the same shape when viewed in the axial direction A. As a result, when the mating surface 2549 on the gear case member 254 side and the mating surface 2509 on the motor case 250 side come into contact in the axial direction A, a substantially closed space is formed by the grooves 25490 and 25090. This closed space then forms the mating surface oil passage 840. In this way, the mating surface oil passage 840 is formed by the contact (metal-to-metal contact) between the mating surfaces 2549 on the gear case member 254 side and 2509 on the motor case 250 side.

[0048] In this embodiment, the mating surface oil passage 840 is located inside the mating surfaces 2508 and 2548 related to the joint 2502 (closer to the first axis C1 when viewed in the axial direction A), i.e., within the housing chamber SP, as described above. Therefore, the mating surface oil passage 840 does not need to be formed by a completely oil-tight closed space. In other words, the mating surfaces 2509 and 2549 related to the mating surface oil passage 840 may be aligned in the axial direction A without the use of a sealing member such as an O-ring. This makes it possible to reduce the number of parts and costs related to the sealing member.

[0049] By the way, as mentioned above in "Problems the Invention Aims to Solve," when an oil passage is formed in Case 2 by machining, the machined hole related to the formed oil passage has an opening (an opening exposed to the outside) formed due to the insertion and removal of the machining drill. Therefore, a plug is required to close such an opening.

[0050] In this embodiment, as described above, mating surface oil passages 840 are formed by the contact (metal-to-metal contact) of the mating surfaces. The grooves 25090 and 25490 that form the mating surface oil passages 840 can be formed by the shape of the mold (for example, the shape of a casting mold) during the manufacturing of the motor case 250 and the gear case member 254, respectively. Therefore, according to this embodiment, since the mating surface oil passages 840 can be formed without machining, the number of plugs and the associated costs can be reduced for the oil passages 84 from the electric oil pump 82 to the oil cooler 90.

[0051] Furthermore, in this embodiment, as described above, unlike oil holes formed by machining, even if the mating surface oil passage 840 has a curved or bent shape in relation to its shape as viewed in the axial direction A, it does not lead to an increase in the number of plugs and the associated increase in cost. Therefore, according to this embodiment, the degree of freedom in the shape of the mating surface oil passage 840 (shape as viewed in the axial direction A) can be increased. As a result, according to this embodiment, the mating surface oil passage 840 can be formed by utilizing the dead space inside the mating surfaces 2508 and 2548 related to the joint 2502 (the side closer to the first axis C1 when viewed in the axial direction A). For example, the space inside the mating surfaces 2508 and 2548 related to the joint 2502 (the side closer to the first axis C1 when viewed in the axial direction A), and the space near the axial position of the mating surfaces 2508 and 2548, is a space that overlaps with the rotating electric machine 1 when viewed in the axial direction A, and is likely to become dead space. By utilizing this dead space to form the mating surface oil passage 840, the mating surface oil passage 840 can be formed without increasing the radial or axial dimensions A of case 2.

[0052] In this embodiment, the mating surface oil passage 840 extends over a circumferential range that is part of the entire circumference around the first shaft C1, and its lower end below the first shaft C1 may be connected to an axial flow path 839 (see Figure 3) from the discharge side of the electric oil pump 82. That is, the mating surface oil passage 840 may communicate with the containment chamber SP via the axial flow path 839 and the electric oil pump 82. In addition, the mating surface oil passage 840 may have its upper end above the first shaft C1 connected to an oil passage 842 (see also Figure 6) to the oil cooler 90.

[0053] In this embodiment as well, the oil passage 84 from the electric oil pump 82 to the oil cooler 90 may have some machined oil passages. For example, as schematically shown by dotted lines in Figure 6, machined oil passages 842, 843, and 844 may be formed in the gear case member 254. In this case, oil passage 842 extends linearly in the axial direction A, and its end on the first axial side A1 is connected to the mating surface oil passage 840 described above. Oil passage 843 extends linearly in a direction intersecting the axial direction A, its radially outer end is connected to oil passage 842, and its radially inner end is connected to the inlet of the oil cooler 90. Oil passage 844 may form a part of the oil passage 86 shown in Figure 2B and extend linearly from the outlet of the oil cooler 90 toward the first axial side A1. In this case, the oil from the mating surface oil passage 840 flows to oil passage 842 (arrow R3031), then to oil passage 843 (arrow R3032), passes through the oil cooler 90, and then flows through oil passage 844 (arrow R306). The oil supplied to oil passage 844 (oil from the electric oil pump 82) may be supplied not only to the axial oil passage 15a of the rotor shaft 15 (see arrows R306 and R308 in Figure 2B) but also to the coil end section 13 (see arrows R306 and R307 in Figure 2B) by branching of oil passage 844. Furthermore, oil may be supplied to the coil end section 13 via the axial oil passage 15a when the rotating electric machine 1 is operating using centrifugal force (see arrow R309 in Figure 2B).

[0054] However, in the modified example, the oil passages 842 and 843 may also be omitted by adjusting the formation range of the mating surface oil passage 840.

[0055] Next, other embodiments will be described with reference to Figure 7. For the sake of distinction, the embodiment described above will also be referred to as "Embodiment 1," and the embodiment described later with reference to Figure 7 will also be referred to as "Embodiment 2."

[0056] Figure 7 is a schematic diagram showing the oil flow in the vehicle drive unit 100A, along with a cross-sectional view of the main parts of the vehicle drive unit 100A according to Example 2.

[0057] The vehicle drive unit 100A according to Embodiment 2 differs from the vehicle drive unit 100 according to Embodiment 1 in the arrangement of the electric oil pump 82 and the strainer 80. Specifically, in Embodiment 1, the electric oil pump 82 and the strainer 80 are located in the gear housing chamber SP2, whereas in Embodiment 2, the electric oil pump 82 and the strainer 80 are located in the motor housing chamber SP1.

[0058] Here, as schematically shown in Figure 7, when the oil temperature sensor 89 is located in the motor housing chamber SP1, the temperature of the electric oil pump 82 can be appropriately controlled based on the oil temperature indicated by the sensor information from the oil temperature sensor 89. Specifically, when the electric oil pump 82 is located in the gear housing chamber SP2 as in Embodiment 1 described above, the electric oil pump 82 tends to become significantly hotter than the oil temperature indicated by the sensor information from the oil temperature sensor 89 in the motor housing chamber SP1 due to the influence of heat received from the differential gear mechanism 5, etc. In this case, it is difficult to appropriately control the temperature of the electric oil pump 82. In contrast, according to Embodiment 2, the electric oil pump 82 is located in the same motor housing chamber SP1 as the oil temperature sensor 89, so the temperature of the electric oil pump 82 can be controlled based on the sensor information from the oil temperature sensor 89.

[0059] Furthermore, if the oil temperature sensor 89 is installed in the motor housing chamber SP1, the wiring 890 between the oil temperature sensor 89 and the control device (not shown) can be routed through the motor housing chamber SP1. For example, the wiring 890 can be routed together with the low-voltage wiring (not shown) of the rotation angle sensor and temperature sensor of the rotating electric machine 1 to the inverter housing chamber (not shown) which houses the inverter (not shown).

[0060] In this second embodiment, the oil passage 84A including the mating surface oil passage 840 described above can also be realized. In this case, the oil passage 84A may differ from the oil passage 84 in the first embodiment from the oil passage 84 in the first embodiment only in the oil passage portion up to the mating surface oil passage 840. That is, only the axial flow path 839 (see Figure 3) or the oil passage portion up to the axial flow path 839 may be different. Such an oil passage can be formed in the motor case 250 by machining, but it may also be formed by a tubular member.

[0061] Although each embodiment has been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope described in the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above.

[0062] For example, in the embodiment described above, the mating surface oil passage 840 is formed by a combination of both grooves 25090 and 25490, but it is not limited to this. That is, even if only one of grooves 25090 and 25490 is formed, a closed oil passage similar to the mating surface oil passage 840 can be formed.

[0063] Furthermore, in the above-described embodiment, the mating surfaces 2509 and 2549, on which the grooves 25090 and 25490 are formed, are formed in a manner that is not continuous with the mating surfaces 2508 and 2548 related to the joint 2502, but they may be partially or entirely continuous. For example, mating surface 2509 and mating surface 2508 may be connected via a connecting surface on the same plane.

[0064] Furthermore, in the above-described embodiment, mating surface oil passages 840 are formed in relation to the mating surfaces 2509 and 2549 between the motor case 250 and the gear case member 254, but mating surface oil passages such as mating surface oil passages 840 may be formed in relation to other mating surfaces.

[0065] Furthermore, in the embodiments described above, the power source is a rotating electric machine 1, but an engine (internal combustion engine) may be included instead of or in addition to the rotating electric machine 1.

[0066] Furthermore, in the embodiment described above, the mating surface oil passage 840 is formed in only one location, but it may be formed in two or more locations that are far apart from each other.

[0067] Furthermore, in the above-described embodiment, the mating surfaces 2508 and 2509 on the motor case 250 side are in the same plane, and the mating surfaces 2548 and 2549 on the gear case member 254 side are in the same plane, but this is not limited to this. As long as the mating surfaces 2508 and 2548 are aligned in the axial direction A and the mating surfaces 2509 and 2549 are aligned in the axial direction A, the mating surfaces 2508 and 2509 on the motor case 250 side may be surfaces that are offset from each other in the axial direction A. [Explanation of symbols]

[0068] 100...Vehicle drive unit, 1...Rotating electric machine (power source), 13...Coil end section (supplied item), 15...Rotor shaft (supplied item), 2...Case, 250...Motor case (case component), 254...Gear case component (cover component), 4...Counter gear mechanism (power transmission mechanism), 5...Differential gear mechanism (power transmission mechanism), 90...Oil cooler, 2508... • Machining surface (1st mating surface), 2548... Machining surface (3rd mating surface), 2509... Machining surface (2nd mating surface), 2549... Machining surface (4th mating surface), 840... Machining surface oil passage (oil passage), 25090, 25490... Groove section, 240, 241, 243... Bearing (supplied item), SP1... Motor housing chamber (1st housing chamber), SP2... Gear housing chamber (2nd housing chamber)

Claims

1. A case that forms a containment chamber through which oil flows, A power transmission mechanism including a rotating shaft member, which is arranged in the aforementioned storage chamber and capable of transmitting power from a power source to the wheels, An oil pump that sucks up and discharges oil from the aforementioned containment chamber, The case comprises an oil passage structure formed in at least a portion thereof, The aforementioned case is, A case member having a first mating surface at its axial end and a second mating surface located radially inward from the first mating surface when viewed in the axial direction of the rotating shaft member, A cover member having a third mating surface that is aligned axially with the first mating surface and a fourth mating surface that is aligned axially with the second mating surface, and being coupled to the case member via a connection between the first mating surface and the third mating surface, The oil passage structure includes an oil passage between the discharge side of the oil pump and the object to which the oil is supplied. The oil passage is formed in such a manner that it is surrounded in the axial direction by at least one of the second mating surface and the fourth mating surface, and has a groove that is recessed in the axial direction with respect to at least one of the mating surfaces. The oil cooler is further attached to the cover member, The oil passage extends from the discharge side of the oil pump to the oil cooler. The groove portion has a curved or bent shape when viewed in the axial direction, in a vehicle drive device.

2. The power source includes a rotating electric machine that is mounted concentrically with the rotating shaft member. The supplied items include the rotating electric machine, The vehicle drive device according to claim 1, wherein the groove overlaps the rotating electric machine when viewed in the axial direction.

3. The vehicle drive device according to claim 1 or 2, wherein the second mating surface and the fourth mating surface can be aligned in the axial direction without the use of a sealing member.

4. A case that forms a containment chamber through which oil flows, A power transmission mechanism including a rotating shaft member, which is arranged in the aforementioned storage chamber and capable of transmitting power from a power source to the wheels, An oil pump that sucks up and discharges oil from the aforementioned containment chamber, The case comprises an oil passage structure formed in at least a portion thereof, The aforementioned case is, A case member having a first mating surface at its axial end and a second mating surface located radially inward from the first mating surface when viewed in the axial direction of the rotating shaft member, A cover member having a third mating surface that is aligned axially with the first mating surface and a fourth mating surface that is aligned axially with the second mating surface, and being coupled to the case member via a connection between the first mating surface and the third mating surface, The oil passage structure includes an oil passage between the discharge side of the oil pump and the object to which the oil is supplied. The oil passage is formed in such a manner that it is surrounded in the axial direction by at least one of the second mating surface and the fourth mating surface, and has a groove that is recessed in the axial direction with respect to at least one of the mating surfaces. The power source includes a rotating electric machine that is mounted concentrically with the rotating shaft member. The housing includes a first housing for housing the rotating electric machine and a second housing adjacent to the first housing in the axial direction and housing at least a part of the power transmission mechanism. The oil pump is electrically operated and is located in the first housing chamber; this is a vehicle drive system.

5. The vehicle drive device according to claim 4, further comprising an oil temperature sensor disposed in the first containment chamber and generating sensor information corresponding to the oil temperature.

6. The vehicle drive device according to claim 4 or 5, wherein the cover member is provided so as to cover the axial end of the second housing chamber that is farther from the first housing chamber.

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