Drive device for vehicle

Abstract

To avoid insufficient lubrication during turning of a vehicle.SOLUTION: A drive device for a vehicle comprises a first motor for driving a right wheel of the vehicle, a first gear mechanism interposed between the first motor and the right wheel, a second motor for driving a left wheel of the vehicle, a second gear mechanism interposed between the second motor and the left wheel, and a casing that accommodates the first gear mechanism and the second gear mechanism. The casing has a first gear chamber for accommodating the first gear mechanism, a second gear chamber for accommodating the second gear mechanism, and a partition wall interposed between the first gear chamber and the second gear chamber. The first gear chamber and the second gear chamber are arranged in a right-left direction of the vehicle across the partition wall. The partition wall is provided with a first communication passage that allows lubrication liquid staying in a lower part of the first gear chamber to flow to the second gear chamber, and a second communication passage that allows lubrication liquid staying in a lower part of the second gear chamber to flow to the first gear chamber, independently of each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a drive device for a vehicle. [Background technology]

[0002] Patent Document 1 describes a drive unit for a vehicle. This drive unit drives left and right wheels independently with two motors. The casing of the drive unit has two gear chambers, which are arranged in the left-right direction of the vehicle with a partition therebetween. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-205444 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a drive unit for a vehicle, when the vehicle turns, there is a problem that the lubricating liquid in the gear chamber is biased due to centrifugal force. In particular, in the drive unit as described above, the lubricating liquid moves toward the partition wall in one gear chamber, while the lubricating liquid moves away from the partition wall in the other gear chamber. As a result, there is a concern that the lubricating liquid will be insufficient for the bearings and gears located near the partition wall in the other gear chamber.

[0005] This specification provides a technique for sufficiently lubricating the vicinity of a partition in a drive unit having two gear chambers even when the vehicle is turning. [Means for solving the problem]

[0006] The technology disclosed in this specification is embodied in a drive device for a vehicle. In one embodiment, the drive device includes a first motor for driving a right wheel of the vehicle, a first gear mechanism interposed between the first motor and the right wheel, a second motor for driving a left wheel of the vehicle, a second gear mechanism interposed between the second motor and the left wheel, and a casing that houses the first gear mechanism and the second gear mechanism together with a lubricating fluid. The casing has a first gear chamber that houses the first gear mechanism, a second gear chamber that houses the second gear mechanism, and a partition wall that is interposed between the first gear chamber and the second gear chamber. The first gear chamber and the second gear chamber are arranged in the left-right direction of the vehicle with the partition wall between them. The partition is provided with a first communication passage that allows the lubricating liquid remaining in the lower part of the first gear chamber to flow to the second gear chamber, and a second communication passage that allows the lubricating liquid remaining in the lower part of the second gear chamber to flow to the first gear chamber, which are independent of each other.

[0007] According to the above-mentioned configuration, the vicinity of the partition wall can be reliably lubricated regardless of the direction in which the vehicle turns. For example, assume that the vehicle turns to the right. In this case, the lubricating liquid moves toward the partition wall in the first gear chamber, whereas the lubricating liquid moves away from the partition wall in the second gear chamber. As a result, the level of the lubricating liquid is low in the vicinity of the partition wall in the second gear chamber, but the lubricating liquid concentrated on the partition wall in the first gear chamber is supplied to the second gear chamber through the first communication passage provided in the partition wall. Similarly, when the vehicle turns to the left, the lubricating liquid concentrated on the partition wall in the second gear chamber is supplied to the first gear chamber through the second communication passage provided in the partition wall. Therefore, the vicinity of the partition wall can be reliably lubricated regardless of the direction in which the vehicle turns.

[0008] In the above embodiment, the first communication passage may have a first inlet opening into the first gear chamber and a first outlet opening into the second gear chamber, and the first inlet may be located above the first outlet. Similarly, the second communication passage may have a second inlet opening into the second gear chamber and a second outlet opening into the first gear chamber, and the second inlet may be located above the second outlet. With this configuration, the lubricating liquid is smoothly supplied from the first gear chamber to the second gear chamber or from the second gear chamber to the first gear chamber depending not only on the action of centrifugal force but also on the liquid level difference of the lubricating liquid on both sides of the partition wall.

[0009] In the above embodiment, the first communication passage may be inclined downward from the first inlet to the first outlet. Similarly, the second communication passage may be inclined downward from the second inlet to the second outlet. With this configuration, the lubricating liquid is more smoothly supplied from the first gear chamber to the second gear chamber, or from the second gear chamber to the first gear chamber, by utilizing gravity acting on the lubricating liquid.

[0010] In the above embodiment, in the first gear chamber, the partition wall may be provided with a first bearing retaining portion that retains a bearing of the first gear mechanism. In this case, the second outlet of the second communication passage may be located at the first bearing retaining portion. Similarly, in the second gear chamber, the partition wall may be provided with a second bearing retaining portion that retains a bearing of the second gear mechanism. In this case, the first outlet of the first communication passage may be located at the second bearing retaining portion. With this configuration, the bearing retained by the partition wall can be more reliably lubricated.

[0011] In the above embodiment, the first bearing retaining portion and the second bearing retaining portion may be located coaxially with the partition wall in between. However, in another embodiment, the first bearing retaining portion and the second bearing retaining portion may be located apart from each other. In this case, the first communication passage and the second communication passage may also be provided apart from each other according to the positions of the bearing retaining portions. [Brief description of the drawings]

[0012] [Figure 1] 1 shows a schematic configuration of a driving device 10 according to an embodiment. [Diagram 2] This shows an enlarged view of part II in FIG. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2 . [Figure 4] The movement of the lubricating fluid LB when the vehicle 2 turns right is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A drive device 10 of the embodiment will be described with reference to the drawings. The drive device 10 is a drive device for a vehicle 2. The vehicle 2 is an electric vehicle. The electric vehicle referred to here is, for example, a battery electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a fuel cell electric vehicle. The drive device 10 is mounted on the vehicle 2 and drives a right wheel 4 and a left wheel 6 of the vehicle 2. The right wheel 4 and the left wheel 6 are arranged coaxially. The right wheel 4 and the left wheel 6 may be the front wheels of the vehicle 2 or the rear wheels of the vehicle 2.

[0014] In the drawings, the direction UP indicates the upward direction in the vertical direction of the vehicle 2, and the direction DW indicates the downward direction in the vertical direction. The direction RH indicates the right direction in the horizontal direction of the vehicle 2, and the direction LH indicates the left direction in the horizontal direction. The direction FR indicates the forward direction in the longitudinal direction of the vehicle 2, and the direction RR indicates the rearward direction in the longitudinal direction.

[0015] As shown in Figs. 1 to 3, the drive device 10 includes a first motor 12, a first gear mechanism 14, a second motor 16, and a second gear mechanism 18. The first motor 12 is a prime mover for driving a right wheel 4 of the vehicle 2. The first motor 12 is connected to the right wheel 4 via the first gear mechanism 14. The second motor 16 is a prime mover for driving a left wheel 6 of the vehicle 2. The second motor 16 is connected to the left wheel 6 via the second gear mechanism 18. The drive device 10 is configured to drive the right wheel 4 and the left wheel 6 independently by the two motors 12, 16.

[0016] The first gear mechanism 14 is interposed between the first motor 12 and the right wheel 4. The first gear mechanism 14 includes a plurality of gears 14g, a plurality of rotating shafts 14s, and a plurality of bearings 14b. The plurality of gears 14g are engaged in series to transmit torque between the first motor 12 and the right wheel 4. Each rotating shaft 14s can hold at least one gear 14g and is rotatably supported by two or more bearings 14b. Although not particularly limited, the first gear mechanism 14 may be a reducer configured to amplify the torque output by the first motor 12 and transmit it to the right wheel 4.

[0017] The second gear mechanism 18 is interposed between the second motor 16 and the left wheel 6. The second gear mechanism 18 includes a plurality of gears 18g, a plurality of rotating shafts 18s, and a plurality of bearings 18b. The plurality of gears 18g are engaged in series to transmit torque between the second motor 16 and the left wheel 6. Each rotating shaft 18s holds at least one gear 18g and is rotatably supported by two or more bearings 18b. The second gear mechanism 18 may be a reducer configured to amplify the torque output by the second motor 16 and transmit it to the left wheel 6.

[0018] The drive device 10 further includes a casing 20. The casing 20 houses the first motor 12, the first gear mechanism 14, the second motor 16, and the second gear mechanism 18 together with lubricating liquid LB. The lubricating liquid LB may be, for example, oil. The casing 20 has a first gear chamber 22, a second gear chamber 24, and a partition wall 26. The first gear chamber 22 houses the first gear mechanism 14, and the second gear chamber 24 houses the second gear mechanism 18. The lubricating liquid LB is retained in the lower portions of the first gear chamber 22 and the second gear chamber 24. The lubricating liquid LB is supplied to various locations in the casing 20 by the rotation of the gears 14g and 18g or by an oil pump (not shown).

[0019] The partition wall 26 is interposed between the first gear chamber 22 and the second gear chamber 24. The first gear chamber 22 and the second gear chamber 24 are arranged in the left-right direction with the partition wall 26 in between. As shown in Figs. 2 and 3, the partition wall 26 is provided with a first communication passage 30 and a second communication passage 32. The first communication passage 30 has a first inlet 30a that opens into the first gear chamber 22 and a first outlet 30b that opens into the second gear chamber 24, and extends from the first inlet 30a to the first outlet 30b. On the other hand, the second communication passage 32 has a second inlet 32a that opens into the second gear chamber 24 and a second outlet 32b that opens into the first gear chamber 22, and extends from the second inlet 32a to the second outlet 32b. Here, the first communication passage 30 and the second communication passage 32 are independent of each other and are not connected to each other by the partition wall 26 .

[0020] According to the above configuration, the vicinity of the partition wall 26 can be reliably lubricated regardless of the direction in which the vehicle 2 turns. For example, assume that the vehicle 2 turns to the right RH. In this case, as shown in FIG. 4, the lubricating liquid LB moves toward the partition wall 26 in the first gear chamber 22, whereas the lubricating liquid LB moves away from the partition wall 26 in the second gear chamber 24. As a result, the liquid level of the lubricating liquid LB is low in the vicinity of the partition wall 26 in the second gear chamber 24. However, the lubricating liquid LB concentrated on the partition wall 26 in the first gear chamber 22 is supplied to the second gear chamber 24 through the first communication passage 30 provided in the partition wall 26 (see arrow F). Similarly, when the vehicle 2 turns to the left LH, the lubricating liquid LB concentrated on the partition wall 26 in the second gear chamber 24 is supplied to the first gear chamber 22 through the second communication passage 32 provided in the partition wall 26. Therefore, the vicinity of the partition wall 26 can be reliably lubricated regardless of the direction in which the vehicle 2 turns.

[0021] Although not particularly limited, the first inlet 30a may be located above the first outlet 30b. And the first communication passage 30 may be inclined downward from the first inlet 30a toward the first outlet 30b. Similarly, the second inlet 32a may be located above the second outlet 32b. And the second communication passage 32 may be inclined downward from the second inlet 32a toward the second outlet 32b. According to such a configuration, not only the centrifugal force acting on the lubricating fluid LB, but also according to the liquid level difference of the lubricating fluid LB on both sides of the partition wall 26, the lubricating fluid LB is smoothly supplied from the first gear chamber 22 to the second gear chamber 24, or from the second gear chamber 24 to the first gear chamber 22.

[0022] However, as another embodiment, the first inlet 30a and the first outlet 30b may be at the same position in the vertical direction, and the first communication passage 30 may extend in the horizontal direction. Even in this case, when the vehicle 2 turns right, the lubricating fluid LB is supplied from the first gear chamber 22 to the second gear chamber 24 through the first communication passage 30 by the centrifugal force acting on the lubricating fluid LB. Similarly, even if the second communication passage 32 extends in the horizontal direction, when the vehicle 2 turns left, the lubricating fluid LB is supplied from the second gear chamber 24 to the first gear chamber 22 through the second communication passage 32.

[0023] Although not particularly limited, in the drive device 10 of the present embodiment, in the first gear chamber 22, the second outlet 32b of the second communication passage 32 is located in the first bearing holding portion 40. The first bearing holding portion 40 is provided on the partition wall 26 and holds the bearing 14b of the first gear mechanism 14. Specifically, the first bearing holding portion 40 has a recess 40a into which the bearing 14b is fitted, and the second outlet 32b of the second communication passage 32 opens into the recess 40a. According to such a configuration, the bearing 14b of the first gear mechanism 14 held by the partition wall 26 can be lubricated more reliably.

[0024] Similarly, in the second gear chamber 24, the first outlet 30b of the first communication passage 30 is located at the second bearing retaining portion 42. The second bearing retaining portion 42 is provided in the partition wall 26 and retains the bearing 18b of the second gear mechanism 18. More specifically, the second bearing retaining portion 42 has a recess 42a in which the bearing 18b is fitted, and the first outlet 30b of the first communication passage 30 opens into the recess 42a. With this configuration, the bearing 18b of the second gear mechanism 18 retained in the partition wall 26 can be more reliably lubricated. The second bearing retaining portion 42 is located coaxially with the first bearing retaining portion 40 across the partition wall 26.

[0025] Although the embodiments of the present technology have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings achieves multiple objectives simultaneously, and achieving one of the objectives itself has technical utility. [Explanation of symbols]

[0026] 2: vehicle, 4: right wheel, 6: left wheel, 10: drive unit, 12: first motor, 14: first gear mechanism, 16: second motor, 18: second gear mechanism, 20: casing, 22: first gear chamber, 24: second gear chamber, 26: partition wall, 30: first communication passage, 30a: first inlet, 30b: first outlet, 32: second communication passage, 32a: second inlet, 32b: second outlet, 40: first bearing retaining portion, 42: second bearing retaining portion, LB: lubricating fluid

Claims

1. A drive device for a vehicle, comprising: a first motor for driving a right wheel of the vehicle; a first gear mechanism interposed between the first motor and the right wheel; a second motor for driving a left wheel of the vehicle; a second gear mechanism interposed between the second motor and the left wheel; a casing that accommodates the first gear mechanism and the second gear mechanism together with a lubricating liquid; Equipped with the casing has a first gear chamber that houses the first gear mechanism, a second gear chamber that houses the second gear mechanism, and a partition wall interposed between the first gear chamber and the second gear chamber, The first gear chamber and the second gear chamber are arranged in the left-right direction of the vehicle with the partition wall therebetween, The partition wall is provided with a first communication passage for allowing the lubricating liquid remaining in the lower portion of the first gear chamber to flow to the second gear chamber, and a second communication passage for allowing the lubricating liquid remaining in the lower portion of the second gear chamber to flow to the first gear chamber, the first communication passage being independent of each other. Drive unit.

2. the first communication passage has a first inlet opening into the first gear chamber and a first outlet opening into the second gear chamber, the first inlet being located above the first outlet, The second communication passage has a second inlet opening into the second gear chamber and a second outlet opening into the first gear chamber, and the second inlet is located above the second outlet. The drive device according to claim 1 .

3. the first communication passage is inclined downward from the first inlet toward the first outlet, The second communication passage is inclined downward from the second inlet toward the second outlet. The drive device according to claim 2.

4. In the first gear chamber, a first bearing holding portion that holds a bearing of the first gear mechanism is provided in the partition wall, and the second outlet of the second communication passage is located in the first bearing holding portion, In the second gear chamber, a second bearing holding portion that holds a bearing of the second gear mechanism is provided in the partition wall, and the first outlet of the first communication passage is located in the second bearing holding portion.

4. A drive device according to claim 2 or 3.

5. The drive device according to claim 4 , wherein the first bearing retaining portion and the second bearing retaining portion are positioned coaxially with the partition wall therebetween.

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