Vehicle drive device

Abstract

A vehicle drive device (1) comprises: a rotary electric machine; a power transmission mechanism (20); a case that houses the rotary electric machine and the power transmission mechanism; and a second oil storage part (62) that is formed in the lower part of the case. The power transmission mechanism (20) is provided with a scoop-up rotary member (71) that scoops up oil (O) which has accumulated in the second oil storage part (62). The case is provided with a connecting passage (80) that connects a housing chamber of the rotary electric machine and a housing chamber (57) of the power transmission mechanism (20). Provided in the case is an oil guide structure (90) for guiding the oil (O) scraped up by the scraping-up rotary member (71) to the connecting passage (80) without returning the oil to the second oil storage part (62).

Description

Vehicle drive unit

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

[0002] For example, a vehicle drive device including a rotating electric machine is used in an electric vehicle, etc. An example of such a vehicle drive device is disclosed in Japanese Patent Laid-Open Publication No. 2023-49662 (Patent Document 1).

[0003] The vehicle drive device (electric power unit 1) of Patent Document 1 includes a rotating electric machine (electric motor 10), output members (output shafts 22L, 22R), a power transmission mechanism (a reduction mechanism 20, a differential mechanism 30), and a case (housing 2) that accommodates the rotating electric machine and the power transmission mechanism. The vehicle drive device also includes an oil reservoir (oil pan P) formed below an accommodation chamber (gear accommodation portion Sg) for the power transmission mechanism, and an oil pump (oil pump 40).

[0004] The power transmission mechanism uses a scraper rotating member (ring gear 26) to scoop up some of the oil accumulated in the oil reservoir to lubricate and cool each part of the power transmission mechanism, and the oil pump draws in and discharges the other part of the oil accumulated in the oil reservoir to lubricate and cool each part of the rotating electric machine.

[0005] JP 2023-49662 A

[0006] However, in the vehicle drive device of Patent Document 1, when the vehicle is running, a large amount of the scraper rotating member is immersed in the oil accumulated in the oil reservoir, which causes a constant large drag resistance of the oil and tends to result in poor drive efficiency.

[0007] Therefore, it is desirable to realize a vehicle drive device that improves drive efficiency when the vehicle is running.

[0008] The vehicle drive device according to the present disclosure comprises: a rotating electric machine having a rotor; an output member drivingly connected to a wheel; a power transmission mechanism for transmitting power between the rotor and the output member; a case having formed therein a first storage chamber for accommodating the rotating electric machine and a second storage chamber for accommodating the power transmission mechanism; a first oil reservoir formed in a lower part of the first storage chamber; a second oil reservoir formed in a lower part of the second storage chamber; and an oil pump, wherein the oil pump draws in and discharges oil accumulated in the first oil reservoir; the power transmission mechanism comprises a scraper rotating member that scoops up oil accumulated in the second oil reservoir; the case comprises a communication passage that connects the first storage chamber and the second storage chamber; and an oil guide structure within the case that guides at least a portion of the oil scooped up by the scraper rotating member to the communication passage without returning it to the second oil reservoir.

[0009] According to this configuration, the oil guide structure allows the oil scooped up by the scraper rotating member to lubricate and cool various parts of the power transmission mechanism, and then at least a portion of the oil is guided to the connecting passage without returning to the second oil reservoir, and then flows from the connecting passage into the first oil reservoir. Therefore, the amount of oil accumulating in the second oil reservoir can be kept small while the scraper rotating member is rotating. This reduces the oil drag resistance caused by the rotation of the scraper rotating member while the vehicle is running, thereby improving the drive efficiency of the vehicle drive system.

[0010] Further features and advantages of the techniques according to the present disclosure will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings.

[0011] A skeleton diagram of a vehicle drive device according to an embodiment. A partially exploded perspective view of a vehicle drive device. An axial view showing a scoop-up lubrication structure. A perspective view showing a first oil guide structure. A perspective view showing the first oil guide structure. An axial view showing the first oil guide structure. An axial view showing a second oil guide structure.

[0012] An embodiment of a vehicle drive device will be described with reference to the drawings. As shown in Fig. 1 and Fig. 2, the vehicle drive device 1 of this embodiment includes a rotating electric machine 10, a power transmission mechanism 20, an output member 40, and a case 50. The power transmission mechanism 20 transmits power between the rotating electric machine 10 and the output member 40. The power transmission mechanism 20 of this embodiment includes an input member 21, a counter gear mechanism 26, a differential input gear 31, and a differential gear mechanism 32. The output member 40 is drivingly connected to a wheel Wh. The case 50 houses the rotating electric machine 10, the power transmission mechanism 20, and the output member 40.

[0013] In this embodiment, the term "rotating electric machine" is used as a concept that includes a motor (electric motor), a generator (electric generator), and a motor-generator that functions as both a motor and a generator as needed.

[0014] Furthermore, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force. This concept includes a state in which two rotating elements are connected so as to rotate integrally, and a state in which two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members (shafts, gear mechanisms, belts, chains, etc.) that transmit rotation at the same speed or at variable speeds, and may also include engagement devices (friction engagement devices, meshing engagement devices, etc.) that selectively transmit rotation and driving force.

[0015] In this embodiment, the rotating electric machine 10 and the input member 21 are disposed on a first axis A1. The rotating electric machine 10 and the input member 21 are disposed so that their common rotational axis is aligned with the first axis A1. The counter gear mechanism 26 is disposed on a second axis A2 different from the first axis A1. The counter gear mechanism 26 is disposed so that its rotational axis is aligned with the second axis A2. The differential input gear 31, the differential gear mechanism 32, and the output member 40 are disposed on a third axis A3 different from the first axis A1 and the second axis A2. The differential input gear 31, the differential gear mechanism 32, and the output member 40 are disposed so that their common rotational axis is aligned with the third axis A3.

[0016] The first axis A1, the second axis A2, and the third axis A3 are arranged parallel to one another. In this embodiment, the direction parallel to each of these axes A1 to A3 is referred to as the "axial direction L." Furthermore, the vertical direction when the vehicle drive device 1 is mounted on a vehicle is referred to as the "up-down direction V." Furthermore, the direction perpendicular to both the axial direction L and the up-down direction V is referred to as the "width direction W." In this embodiment, the axial direction L is the left-right direction of the vehicle (vehicle width direction), and the width direction W is the front-rear direction of the vehicle.

[0017] In the following description, one side in the axial direction L, where the rotating electric machine 10 is arranged relative to the counter gear mechanism 26, will be referred to as the "first axial side L1," and the opposite side (the other side in the axial direction L, where the counter gear mechanism 26 is arranged relative to the rotating electric machine 10) will be referred to as the "second axial side L2." Furthermore, one side in the width direction W, where the counter gear mechanism 26 is arranged relative to the differential gear mechanism 32, will be referred to as the "first width direction side W1," and the opposite side (the other side in the width direction W, where the differential gear mechanism 32 is arranged relative to the counter gear mechanism 26) will be referred to as the "second width direction side W2."

[0018] In this embodiment, the vehicle drive device 1 further includes a first oil reservoir 61, a second oil reservoir 62, and an oil pump 65. The first oil reservoir 61 and the second oil reservoir 62 are formed in the lower part of the case 50. The oil pump 65 is provided in the first oil reservoir 61.

[0019] The rotating electric machine 10 has a stator 11 and a rotor 12. The stator 11 is fixed to a case 50, which is a non-rotating member. The rotor 12 is disposed radially inward of the stator 11 and is supported rotatably relative to the stator 11. The rotor 12 is coupled to a rotor shaft 13 so as to rotate integrally with the rotor 12. The rotor shaft 13 is drivingly coupled to a power transmission mechanism 20. The rotor shaft 13 is coupled to an input member 21 constituting the power transmission mechanism 20 at an end on a second axial side L2 so as to rotate integrally with the input member 21.

[0020] The power transmission mechanism 20 transmits power between the rotor 12 and the output member 40. The power transmission mechanism 20 includes an input member 21, a counter gear mechanism 26, a differential input gear 31, and a differential gear mechanism 32. The input member 21 is a member in the power transmission mechanism 20 to which driving force from the rotating electric machine 10 (rotor 12) is input. The input member 21 is connected to the rotor shaft 13 at an end on a first axial side L1 so as to rotate integrally with the rotor shaft 13. An input gear 22 is formed on the outer surface of the end on a second axial side L2 of the input member 21. The input gear 22 is drivingly connected to the counter gear mechanism 26.

[0021] The counter gear mechanism 26 has a first counter gear 27, a second counter gear 28, and a counter shaft 29. The first counter gear 27 meshes with the input gear 22. The second counter gear 28 has fewer teeth than the first counter gear 27, and in this embodiment, is disposed on the first axial side L1 relative to the first counter gear 27. The counter shaft 29 integrally connects the first counter gear 27 and the second counter gear 28. The second counter gear 28 meshes with a differential input gear 31. In this way, the driving force from the rotor 12 is transmitted to the differential input gear 31 via the input member 21 and the counter gear mechanism 26.

[0022] The differential input gear 31 is drivingly connected to a differential gear mechanism 32. The differential gear mechanism 32 has a pair of pinion gears 33, a pair of side gears 34 that mesh with the pair of pinion gears 33, respectively, and a differential case 35 that houses these. The differential input gear 31 meshes with the second counter gear 28 and is connected to the differential case 35 so as to rotate integrally with it. The pinion gear 33 is rotatably supported on a pinion shaft that is supported on the differential case 35 in a state perpendicular to the third axis A3. The side gear 34 is connected to an output member 40 so as to rotate integrally with it. The differential gear mechanism 32 distributes the driving force transmitted to the differential input gear 31 to the pair of output members 40.

[0023] The pair of output members 40 are each connected to a wheel Wh via an axle DS.

[0024] As shown in FIGS. 1 and 2 , the case 50 includes a case main body 51, a first cover 52, a second cover 53, and a third cover 54. The case main body 51 is a main body portion that houses the rotating electric machine 10 and the power transmission mechanism 20. The case main body 51 includes a peripheral wall 51A that covers the outer peripheries of the rotating electric machine 10 and the power transmission mechanism 20, and a partition wall 51B that partitions the internal space in the axial direction L. The partition wall 51B is provided between the rotating electric machine 10 and the power transmission mechanism 20 in the axial direction L. In this embodiment, on the first axis A1, the rotor shaft 13 and the input member 21 are connected at a portion that penetrates the partition wall 51B. On the third axis A3, one axle DS is disposed so as to penetrate the partition wall 51B.

[0025] The first cover 52 and the second cover 53 are fixed to the case body 51 in the axial direction L. The first cover 52 is fixed to the case body 51 from a first axial side L1. The second cover 53 is fixed to the case body 51 from a second axial side L2. The third cover 54 is fixed to a box-shaped portion formed on the outer surface of the peripheral wall 51A of the case body 51 with its opening facing the second widthwise side W2.

[0026] In this embodiment, a first housing chamber 56 is formed as a space surrounded by the peripheral wall 51A, the partition wall 51B, and the first cover 52 of the case main body 51. The first housing chamber 56 mainly houses the rotating electric machine 10. A second housing chamber 57 is formed as a space surrounded by the peripheral wall 51A, the partition wall 51B, and the second cover 53. The second housing chamber 57 mainly houses the power transmission mechanism 20. In this way, the inside of the case 50 is formed with the first housing chamber 56 that mainly houses the rotating electric machine 10 and the second housing chamber 57 that mainly houses the power transmission mechanism 20.

[0027] In this embodiment, a third housing chamber 58 is formed as a space surrounded by the outer box-shaped portion of the peripheral wall 51A of the case body 51 and the third cover 54. The third housing chamber 58 mainly accommodates the inverter device 45 that controls the rotating electric machine 10. In this way, the third housing chamber 58, which mainly accommodates the inverter device 45, is formed integrally with the case 50 on the outside of the case 50.

[0028] In this embodiment, a first oil reservoir 61 that stores oil O is formed in a lower portion of the first housing chamber 56 inside the case 50. In this embodiment, the first oil reservoir 61 is configured by an oil pan 64 that is fixed to the case main body 51 from below so as to cover a downward opening formed in the case main body 51 (particularly the peripheral wall 51A here) below the rotating electric machine 10. An oil pump 65 is provided in the first oil reservoir 61. The oil pump 65 is fixed to the upper surface of the oil pan 64. An electric oil pump is used as the oil pump 65.

[0029] The oil pump 65 draws in and discharges the oil O stored in the first oil reservoir 61. The oil O discharged from the oil pump 65 is supplied to the rotating electrical machine 10 via an oil cooler to cool the rotating electrical machine 10. For example, the oil O is allowed to drip from the top of the stator 11 or is centrifugally supplied to the rotor 12 from an oil passage formed inside the rotor shaft 13, thereby cooling the stator 11 and the rotor 12. The discharged oil O is also supplied to bearings provided in various parts of the vehicle drive device 1 (particularly, various parts of the first housing chamber 56) to lubricate the bearings. After being used for these purposes, the oil O flows down and is again stored in the first oil reservoir 61.

[0030] In this embodiment, a second oil reservoir 62 that stores oil O separately from the first oil reservoir 61 is formed in a lower portion of the second housing chamber 57 inside the case 50. As shown in FIG. 3 , the second oil reservoir 62 is configured by a gear surrounding wall 82 formed in the case main body 51 (particularly the peripheral wall 51A in this case) so as to surround a portion of the differential input gear 31 in the circumferential direction. The gear surrounding wall 82 is formed so as to surround the differential input gear 31 from below to above via the second widthwise side W2. The second oil reservoir 62 is configured by a downwardly convex arc-shaped portion of the gear surrounding wall 82 that covers the below of the differential input gear 31.

[0031] The differential input gear 31 rotates when the vehicle is traveling, and as the differential input gear 31 rotates, it scoops up the oil O that has accumulated in the second oil reservoir 62. In this embodiment, when the vehicle is traveling forward, the differential input gear 31 rotates clockwise as viewed from the second axial side L2, and most of the scooped-up oil O splashes from the top of the differential input gear 31 toward the first widthwise side W1. In this embodiment, the differential input gear 31 that scoops up the oil O that has accumulated in the second oil reservoir 62 constitutes a scraping rotation member 71.

[0032] The oil O that splashes toward the first widthwise side W1 reaches the counter gear mechanism 26, which is located on the first widthwise side W1 relative to the third shaft A3 on which the differential input gear 31 is located, and lubricates and cools the counter gear mechanism 26. For example, some oil splashes at the meshing portion between the differential input gear 31 and the second counter gear 28 and in the axial direction L, and reaches the first counter gear 27, lubricating and cooling them. In this embodiment, the counter gear mechanism 26, which constitutes part of the power transmission mechanism 20 together with the differential input gear 31 as the scraper rotating member 71, constitutes the separate rotating member 72. The splashed oil O also lubricates bearings provided in various parts of the vehicle drive system 1 (particularly, various parts of the second housing chamber 57).

[0033] After being used for these purposes, the oil O flows down along the inner surface of the peripheral wall 51A of the case body 51 toward the second oil reservoir 62. In this embodiment, the peripheral wall 51A of the case body 51 has a lower inclined wall 83 below the counter gear mechanism 26 that is inclined downward toward the second widthwise side (in this example, toward the third shaft A3 on which the differential input gear 31 is disposed). The oil O flows down along the inner surface of this lower inclined wall 83 toward the second oil reservoir 62.

[0034] The oil O flowing down along the lower inclined wall 83 flows toward the second oil reservoir 62, but in the vehicle drive device 1 of this embodiment, not all of the oil O returns to the second oil reservoir 62. Rather, most of the oil O flowing down along the lower inclined wall 83 is configured to head toward the first oil reservoir 61 without returning to the second oil reservoir 62.

[0035] 3 and 4 , in this embodiment, a first through-hole 81 penetrating in the axial direction L is formed in the partition wall 51B constituting the case main body 51 at a position on the first widthwise side W1 relative to the second oil reservoir 62. The first through-hole 81 is formed near the end of the differential input gear 31, which is the scraper rotation member 71, on the first widthwise side W1, below the counter gear mechanism 26. The first through-hole 81 is also formed further below the third axis A3 on which the differential input gear 31, which is the scraper rotation member 71, is disposed. The first through-hole 81 is also formed in the partition wall 51B near a connection position between a gear surrounding wall 82 and a lower inclined wall 83, both of which are part of the peripheral wall 51A.

[0036] The first through-hole 81 penetrates the partition wall 51B in the axial direction L, thereby connecting the first storage chamber 56 and the second storage chamber 57 that are partitioned by the partition wall 51B in the axial direction L. In the present embodiment, the first through-hole 81 forms a communication passage 80 that connects the first storage chamber 56 and the second storage chamber 57.

[0037] In this embodiment, the communication passage 80 refers to a passage that is specially designed to communicate with a location that would not normally be connected. Therefore, structurally essential portions such as openings for arranging rotating members that constitute the power transmission path from the rotating electric machine 10 to the wheels Wh (for example, openings for inserting the rotor shaft 13, input member 21, axle DS, etc.) are not included in the communication passage 80.

[0038] In this embodiment, the case 50 (case main body 51) has a partition wall 85 near the connection position between the gear surrounding wall 82 and the lower inclined wall 83. The partition wall 85 is formed so as to extend obliquely upward from the connection position between the gear surrounding wall 82 and the lower inclined wall 83 along an extension of the gear surrounding wall 82. The partition wall 85 separates the second oil reservoir 62 from an area in which the first through hole 81, which serves as the communication passage 80, is formed in the width direction W. The partition wall 85 is provided at a position adjacent to the first through hole 81 on the second width direction side W2. In this embodiment, the upper side of the partition wall 85 is open. In this embodiment, the height of the upper end of the partition wall 85 is approximately equal to the height of the upper end of the first through hole 81.

[0039] 5 , in this embodiment, the partition wall 85 is formed not only in the case body 51 but also between the case body 51 and the second cover 53. The partition wall 85 has a body-side partition wall 85A and a cover-side partition wall 85B, which are joined in the axial direction L. The partition wall 85 is formed over the entire area of ​​the second housing chamber 57 in the axial direction L.

[0040] In this embodiment, the partition wall 85 has a second through hole 86 penetrating through it in the thickness direction. The second through hole 86 has an opening area smaller than that of the first through hole 81, which is the communication passage 80. The second through hole 86 is also formed slightly above the lowest point of the first through hole 81, which is the communication passage 80. In this embodiment, the second through hole 86 is formed at the joint between the main body side partition wall 85A and the cover side partition wall 85B.

[0041] The partition wall 85 blocks the oil O flowing down along the lower inclined wall 83. By blocking the flow along the lower inclined wall 83, the partition wall 85 prevents the oil O from returning to the second oil reservoir 62, while guiding the blocked oil O toward the first through-hole 81, which is the communication passage 80. As described above, the vehicle drive device 1 of this embodiment is provided with a first oil guide structure 90 in the case 50 that guides at least a portion of the oil O scooped up by the differential input gear 31, which is the scraper rotating member 71, to the first through-hole 81, which is the communication passage 80, without returning the oil O to the second oil reservoir 62. In this embodiment, the first oil guide structure 90 corresponds to the "oil guide structure."

[0042] In addition, a second through hole 86 is formed in the partition wall 85, but its opening area is sufficiently smaller than that of the first through hole 81, which is the connecting passage 80, and the flow of oil O is dominated by the flow toward the first through hole 81, which is the connecting passage 80.

[0043] By providing this first oil guide structure 90, the oil O that flows down along the lower inclined wall 83 after lubricating and cooling the power transmission mechanism 20 is guided to the first through-hole 81, which is the communication passage 80, without returning to the second oil reservoir 62, as shown in FIGS. 4 and 5 (solid arrows). Then, as shown in FIG. 6, the oil O flows from the first through-hole 81, which is the communication passage 80, into the first oil reservoir 61. Therefore, while the vehicle is traveling (i.e., while the differential input gear 31, which is the scraper rotating member 71, is rotating), the amount of oil O that accumulates in the second oil reservoir 62 can be kept low. By lowering the oil level in the second oil reservoir 62 (see FIG. 3), the drag resistance of the oil O caused by the rotation of the differential input gear 31, which is the scraper rotating member 71, during vehicle traveling can be kept low, thereby improving the drive efficiency of the vehicle drive system 1.

[0044] In this embodiment, the first through-hole 81 formed in the partition wall 51B is an opening for allowing the oil O blocked by the partition wall 85 to flow into the first oil reservoir 61, which is the "special intention" described above. This is why the first through-hole 81 serves as the communication passage 80 in this embodiment.

[0045] When the vehicle is stopped for a long period of time, the oil O that had been distributed throughout the various parts of the vehicle drive device 1 while the vehicle was running flows down and returns to the first oil reservoir 61. When the oil level in the first oil reservoir 61 rises and eventually becomes higher than the lowest point of the first through-hole 81, which is the communication passage 80, some of the oil O that has accumulated in the first oil reservoir 61 begins to flow back through the first through-hole 81, which is the communication passage 80 (see the dashed arrow in FIG. 5 ).

[0046] The oil O is then blocked by the partition wall 85 and accumulates on the first widthwise side W1. When the oil level eventually rises above the lowest point of the second through-hole 86, the oil O returns to the second oil reservoir 62 through the second through-hole 86. In this way, the amount of oil O accumulated in the second oil reservoir 62 can be restored and the oil level in the second oil reservoir 62 can be raised while the vehicle is stopped for an extended period of time (see the dashed line in FIG. 3). Therefore, when the vehicle next starts, the oil O accumulated in the second oil reservoir 62 can be sufficiently scooped up by the differential input gear 31, which is the scooping rotating member 71, and the power transmission mechanism 20 can be quickly lubricated and cooled.

[0047] 7 , the peripheral wall 51A constituting the case main body 51 has a surrounding wall 88 formed to surround the outer periphery of the differential gear mechanism 32, at a position adjacent to the first axial side L1 of the gear surrounding wall 82. In this embodiment, an inward rib 89 is formed near the upper portion (the uppermost portion in the illustrated example) of the surrounding wall 88. The inward rib 89 is formed to extend in the axial direction L and protrude radially inward.

[0048] A portion of the oil O scooped up from the second oil reservoir 62 by the differential input gear 31, which is the scraper rotation member 71, splashes slightly in the axial direction L while being scooped up and reaches the inner surface of the surrounding wall 88. The oil O adhering to the inner surface of the surrounding wall 88 is collected by the inward ribs 89 formed on the upper part of the surrounding wall 88 and flows down along the inward ribs 89. The inward ribs 89 serve to guide a portion of the oil O scooped up by the differential input gear 31, which is the scraper rotation member 71, to the differential gear mechanism 32. As described above, the vehicle drive device 1 of this embodiment includes, in addition to the first oil guide structure 90 described above, a second oil guide structure 95 in the case 50 that guides at least a portion of the oil O scooped up by the differential input gear 31, which is the scraper rotation member 71, to the differential gear mechanism 32.

[0049] By providing such a second oil guide structure 95, a portion of the oil O scooped up by the differential input gear 31, which is the scraper rotating member 71, can be efficiently guided to the differential gear mechanism 32. This can lubricate and cool the support portion of the pinion gear 33, the support portion of the side gear 34, the meshing portion between the pinion gear 33 and the side gear 34, and the like. For example, when the vehicle starts to travel, each part of the differential gear mechanism 32 can be quickly and appropriately lubricated. Furthermore, even when the oil level in the second oil reservoir 62 drops during steady vehicle travel and the amount of oil O scooped up by the differential input gear 31, which is the scraper rotating member 71, decreases, each part of the differential gear mechanism 32 can still be appropriately lubricated.

[0050] Other Embodiments (1) In the above embodiment, an example has been described in which the communication passage 80 is configured as a first through hole 81 formed in the partition wall 51B, and the first oil guide structure 90 is configured using such a first through hole 81. However, the present invention is not limited to such a configuration, and for example, the communication passage 80 may be configured as an oil passage, and the first oil guide structure 90 may be configured using such an oil passage. Furthermore, the first oil guide structure 90 may be configured using a separate member attached to the case 50. In addition, any specific configuration of the communication passage 80 and the first oil guide structure 90 may be adopted as long as it is suitable for the purpose.

[0051] (2) In the above embodiment, the second oil guide structure 95 is configured by the inward rib 89 formed on the peripheral wall 51A. However, the present invention is not limited to such a configuration, and any specific structure of the second oil guide structure 95 may be adopted as long as it is suitable for the purpose. Furthermore, the second oil guide structure 95 does not necessarily have to be provided inside the case 50.

[0052] (3) In the above embodiment, an example has been described in which the first oil reservoir 61 is configured using the oil pan 64 fixed to the case body 51. However, the present invention is not limited to such a configuration, and the first oil reservoir 61 may be configured using, for example, a portion of the peripheral wall 51A of the case body 51 that is located below the rotating electric machine 10.

[0053] (4) In the above embodiment, an example has been described in which the second oil reservoir 62 is configured using a portion of the peripheral wall 51A of the case main body 51 that is located below the differential input gear 31. However, the present invention is not limited to such a configuration, and the second oil reservoir 62 may be configured using, for example, an oil pan that is fixed to cover an opening formed below the differential input gear 31 in the case main body 51.

[0054] (5) In the above embodiment, the power transmission mechanism 20 has been described as including the input member 21, the counter gear mechanism 26, the differential input gear 31, and the differential gear mechanism 32. However, the power transmission mechanism 20 is not limited to such a configuration. For example, the power transmission mechanism 20 may further include an idle gear interposed between the input member 21 and the counter gear mechanism 26 or between the counter gear mechanism 26 and the differential input gear 31. In this case, the idle gear may be the separate rotating member 72. Alternatively, the power transmission mechanism 20 may include any other specific configuration, such as a planetary gear reduction device, or a friction engagement device such as a clutch or a brake.

[0055] (6) In the above embodiment, a configuration has been described in which the rotation axis (second axis A2) of the counter gear mechanism 26, which is the separate rotating member 72, is disposed on the first widthwise side W1 relative to the rotation axis (third axis A3) of the differential input gear 31, which is the scraper rotating member 71. However, the present invention is not limited to such a configuration, and the rotation axis of the separate rotating member 72 and the rotation axis of the scraper rotating member 71 may be disposed at the same position in the widthwise direction W. Alternatively, the rotation axis of the separate rotating member 72 may be disposed on the second widthwise side W2 relative to the rotation axis of the scraper rotating member 71.

[0056] (7) In the above embodiment, the differential input gear 31 that rotates when the vehicle is traveling is described as an example of a configuration in which the scraper rotating member 71 scrapes up the oil O that has accumulated in the second oil reservoir 62. However, without being limited to such a configuration, the scraper rotating member 71 may be configured as a rotating member other than the differential input gear 31, for example, by providing a dedicated member for scraping up the oil O that has accumulated in the second oil reservoir 62.

[0057] (8) In the above embodiment, an electric oil pump is used as the oil pump 65. However, the present invention is not limited to such a configuration, and the oil pump 65 may be, for example, a mechanical oil pump that is operated by the driving force of the rotating electric machine 10, which is also the driving force source of the vehicle.

[0058] (9) In the above embodiment, the vehicle drive device 1 has been described assuming a configuration in which it is used as a drive device for an electric vehicle. However, the present disclosure is not limited to such a configuration, and the technology of the present disclosure can be similarly applied to a drive device for a hybrid vehicle, for example.

[0059] (10) In the above embodiment, the output member 40 is connected to the pair of side gears 34 that constitute the differential gear mechanism 32 so as to rotate integrally with them. However, the present invention is not limited to such a configuration, and for example, the axle DS connected to the output member 40 in the above embodiment may be considered the “output member.”

[0060] (11) The configurations disclosed in the above-described embodiments (including the above-described embodiments and other embodiments; the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction occurs. Regarding other configurations, the embodiments disclosed in this specification are examples in all respects and can be appropriately modified within the scope of the present disclosure.

[0061] Summary of the embodiment To summarize the above, the vehicle drive device according to the present disclosure preferably includes the following configurations.

[0062] a power transmission mechanism (20) for transmitting power between the rotor (12) and the output member (40); a case (50) having a first housing chamber (56) for housing the rotary electric machine (10) and a second housing chamber (57) for housing the power transmission mechanism (20); a first oil reservoir (61) formed below the first housing chamber (56); a second oil reservoir (62) formed below the second housing chamber (57); and an oil pump (65), wherein the oil pump (65) sucks in and discharges oil (O) stored in the first oil reservoir (61). The power transmission mechanism (20) includes a scraper rotating member (71) that scrapes up the oil (O) accumulated in the second oil storage section (62), the case (50) includes a communication passage (80) that connects the first storage chamber (56) and the second storage chamber (57), and the case (50) includes an oil guide structure (90) that guides at least a portion of the oil (O) scraped up by the scraper rotating member (71) to the communication passage (80) without returning it to the second oil storage section (62).

[0063] According to this configuration, by providing the oil guide structure (90), after the oil (O) scooped up by the scraper rotating member (71) lubricates and cools each part of the power transmission mechanism (20), at least a portion of the oil (O) is guided to the communication passage (80) without returning to the second oil reservoir (62), and flows from the communication passage (80) into the first oil reservoir (61). Therefore, while the scraper rotating member (71) is rotating, the amount of oil (O) that accumulates in the second oil reservoir (62) can be kept small. Therefore, the drag resistance of the oil (O) caused by the rotation of the scraper rotating member (71) while the vehicle is running can be kept small, and the drive efficiency of the vehicle drive device (1) can be improved.

[0064] In one aspect, the direction along the rotation axis of the scraper rotating member (71) is defined as the axial direction (L), the direction perpendicular to both the axial direction (L) and the vertical direction (V) is defined as the width direction (W), and one side of the width direction (W) is defined as a first width direction side (W1), the scraper rotating member (71) scatters at least a portion of the scraped-up oil (O) toward the first width direction side (W1), the communicating passage (80) is arranged on the first width direction side (W1) with respect to the second oil storage section (62), and it is preferable that the oil guide structure (90) includes a partition wall (85) that separates the second oil storage section (62) and an area in which the communicating passage (80) is arranged in the width direction (W).

[0065] According to this configuration, at least a portion of the oil (O) that is scooped up by the scraper rotating member (71) and scattered toward the first width direction side (W1) is blocked by the partition wall (85) and does not return to the second oil reservoir (62), but is instead guided to the communicating passage (80). Therefore, with a relatively minor modification of providing the partition wall (85) between the second oil reservoir (62) and the area where the communicating passage (80) is disposed, the oil guide structure (90) according to the present disclosure can be appropriately formed within the case (50).

[0066] In one embodiment, the direction along the rotation axis of the scraper rotating member (71) is defined as the axial direction (L), the direction perpendicular to both the axial direction (L) and the up-down direction (V) is defined as the width direction (W), and one side of the width direction (W) is defined as a first width direction side (W1), the scraper rotating member (71) scatters at least a portion of the scraped-up oil (O) toward the first width direction side (W1), the communicating passage (80) is arranged on the first width direction side (W1) with respect to the second oil storage section (62), and the power transmission mechanism (20) includes a separate rotating member (72) that is a rotating member different from the scraper rotating member (71), and it is preferable that the rotation axis of the separate rotating member (72) is arranged on the first width direction side (W1) with respect to the rotation axis of the scraper rotating member (71).

[0067] According to this configuration, the oil (O) scooped up by the scraper rotating member (71) and scattered toward the first widthwise side (W1) can lubricate and cool the separate rotating member (72). After lubricating and cooling the separate rotating member (72), the oil (O) then flows downward, and at least a portion of the oil (O) is guided to the communicating passage (80) located on the same first widthwise side (W1) as the separate rotating member (72) relative to the second oil reservoir (62). Thus, the oil guide structure (90) according to the present disclosure can be appropriately formed within the case (50) while appropriately lubricating and cooling the separate rotating member (72).

[0068] In one embodiment, the power transmission mechanism (20) comprises a differential input gear (31) to which the driving force from the rotor (12) is transmitted, and a differential gear mechanism (32) that distributes the driving force transmitted to the differential input gear (31) to a pair of the output members (40), the scraper rotating member (71) is the differential input gear (31), and it is preferable that the case (50) includes a second oil guide structure (95) that guides at least a portion of the oil (O) scraped up by the differential input gear (31) to the differential gear mechanism (32).

[0069] According to this configuration, at least a portion of the oil (O) scooped up by the differential input gear (31) serving as the scraper rotating member (71) is guided to the differential gear mechanism (32). Therefore, for example, when the vehicle starts to travel, the differential gear mechanism (32) can be quickly and appropriately lubricated. Furthermore, even when the oil level in the second oil reservoir (62) drops and the amount of oil (O) scooped up by the differential input gear (31) decreases during steady travel of the vehicle, the differential gear mechanism (32) can be appropriately lubricated.

[0070] It is sufficient for the vehicle drive device according to the present disclosure to achieve at least one of the above-described effects.

[0071] 1: Vehicle drive device, 10: Rotating electric machine, 11: Stator, 12: Rotor, 13: Rotor shaft, 20: Power transmission mechanism, 21: Input member, 22: Input gear, 26: Counter gear mechanism, 27: First counter gear, 28: Second counter gear, 29: Counter shaft, 31: Differential input gear, 32: Differential gear mechanism, 33: Pinion gear, 34: Side gear, 35: Differential case, 40: Output member, 45: Inverter device, 50: Case, 51: Case body, 51A: Peripheral wall, 51B: Partition wall, 52: First cover, 53: Second cover, 54: Third cover, 56: First housing chamber, 57: Second housing chamber, 58: Third housing chamber , 61: First oil reservoir, 62: Second oil reservoir, 64: Oil pan, 65: Oil pump, 71: Rotating scraper member, 72: Separate rotating member, 80: Communication passage, 81: First through hole, 82: Gear surrounding wall, 83: Lower inclined wall, 85: Partition wall, 85A: Main body side partition wall, 85B: Cover side partition wall, 86: Second through hole, 88: Surrounding wall, 89: Inward rib, 90: First oil guide structure, 95: Second oil guide structure, A1: First shaft, A2: Second shaft, A3: Third shaft, DS: Axle, L: Axial direction, L1: First axial side, L2: Second axial side, O: Oil, V: Vertical direction, W: Width direction, W1: First width side, W2: Second width side, Wh: Wheel

Claims

1. A vehicle drive device comprising: a rotating electric machine having a rotor; an output member drivingly connected to a wheel; a power transmission mechanism for transmitting power between the rotor and the output member; a case having a first storage chamber for accommodating the rotating electric machine and a second storage chamber for accommodating the power transmission mechanism formed therein; a first oil reservoir formed in a lower part of the first storage chamber; a second oil reservoir formed in a lower part of the second storage chamber; and an oil pump, wherein the oil pump draws in and discharges oil accumulated in the first oil reservoir; the power transmission mechanism comprises a rotating scraper member that scoops up oil accumulated in the second oil reservoir; the case has a communication passage that connects the first storage chamber and the second storage chamber; and an oil guide structure within the case that guides at least a portion of the oil scooped up by the rotating scraper member to the communication passage without returning it to the second oil reservoir.

2. A vehicle drive device as described in claim 1, wherein the direction along the rotation axis of the scraper rotating member is defined as the axial direction, the direction perpendicular to both the axial direction and the up-down direction is defined as the width direction, and one side of the width direction is defined as a first width side, the scraper rotating member scatters at least a portion of the oil it scoops up toward the first width side, the communicating passage is arranged on the first width side of the second oil storage section, and the oil guide structure includes a partition wall that separates the second oil storage section and the area in which the communicating passage is arranged in the width direction.

3. A vehicle drive device as described in claim 1, wherein the direction along the rotation axis of the scraper rotating member is defined as the axial direction, the direction perpendicular to both the axial direction and the up-down direction is defined as the width direction, and one side of the width direction is defined as a first width side, the scraper rotating member scatters at least a portion of the oil it scoops up toward the first width side, the communicating passage is arranged on the first width side relative to the second oil storage section, the power transmission mechanism includes a separate rotating member that is a rotating member different from the scraper rotating member, and the rotation axis of the separate rotating member is arranged on the first width side relative to the rotation axis of the scraper rotating member.

4. A vehicle drive device as described in any one of claims 1 to 3, wherein the power transmission mechanism comprises a differential input gear to which driving force from the rotor is transmitted, and a differential gear mechanism that distributes the driving force transmitted to the differential input gear to a pair of the output members, the scraper rotating member is the differential input gear, and a second oil guide structure is provided within the case that guides at least a portion of the oil scraped up by the differential input gear to the differential gear mechanism.

Images