Driving unit

Abstract

To provide a driving unit which can form a space in a driving unit case while inhibiting increase of a vertical dimension.SOLUTION: A driving unit 10 includes: a driving motor 20; a speed reducer 30; and a driving unit case 11 which houses the driving motor 20 and the speed reducer 30. An output rotary shaft of the driving motor 20 and an output rotary shaft of the speed reducer 30 are disposed and arranged parallel to each other and side by side in a horizontal direction. The driving unit case 11 has: a motor chamber 12 which houses the driving motor 20; and a gear chamber 13 provided with a housing chamber 130 which houses the speed reducer 30. The motor chamber 12 and the gear chamber 13 are defined by a second partition wall 114b. An upper space 131 and a lower space 132 which are vertically separated by a vertical partition wall 114c extending from the second partition wall 114b are formed between the motor chamber 12 and the housing chamber 130.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a drive unit mounted on an electric vehicle or the like. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technologies is being conducted in vehicles to reduce CO2 emissions and improve energy efficiency.

[0003] In vehicle electrification technology, there is a demand for smaller drive units, particularly in terms of height, to increase the freedom of installation in vehicles. There is also a demand for more efficient power transmission to improve electricity consumption and driving range.

[0004] For example, Patent Document 1 describes a drive unit whose lubricating performance is improved by forming a space in a drive unit case in which lubricating oil is stored. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-180477 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the drive unit described in Patent Document 1, a space in which lubricating oil is stored is formed above the drive gear provided on the main shaft of the reducer, which causes a problem that the vertical dimension of the drive unit becomes large.

[0007] The present invention provides a drive unit that can form a space in the drive unit case by suppressing an increase in the vertical dimension. [Means for solving the problem]

[0008] The present invention relates to A drive motor; a reduction gear device that reduces the power of the drive motor and outputs the reduced power; a drive unit case that houses the drive motor and the reduction gear; A drive unit comprising: an output rotation shaft of the drive motor and an output rotation shaft of the reduction gear device are arranged parallel to each other and aligned in a horizontal direction, The drive unit case includes: a motor chamber in which the drive motor is accommodated; a gear chamber having an accommodation chamber for accommodating the reduction gear device; The motor chamber and the gear chamber are partitioned by a partition wall, Between the motor chamber and the accommodation chamber, an upper space and a lower space are formed which are separated vertically by upper and lower partition walls extending from the partition wall. It is a drive unit. Effect of the Invention

[0009] According to the present invention, the upper and lower spaces can be formed in the drive unit case while preventing the vertical dimensions from becoming large. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a drive unit according to an embodiment of the present invention, viewed from the left side; [Diagram 2] FIG. 2 is a perspective view showing a drive unit according to an embodiment of the present invention with a part cut away. [Diagram 3] 3 is a partially cutaway perspective view for explaining a power transmission path in the drive unit of FIG. 2. FIG. [Figure 4] 3 is a skeleton diagram of a reduction gear in the drive unit of FIG. 2. [Diagram 5] 3A and 3B are a top view and a left side view of the drive unit of FIG. 2. [Figure 6] 3 is a perspective view of the left main case of the drive unit of FIG. 2, as viewed from the left. [Figure 7] 6 is a cross-sectional view taken along line AA in FIG. 5. [Figure 8] 3 is a perspective view of the left main case of the drive unit in FIG. 2, seen from the right. [Figure 9] 3 is a perspective view of the right main case of the drive unit in FIG. 2, seen from the left. [Figure 10] 6 is a cross-sectional view of FIG. 5 taken along line B-B. [Figure 11] FIG. 3 is a block diagram of a temperature adjustment system in the drive unit of FIG. 2. [Figure 12] 3 is a perspective view of the drive unit of FIG. 2, cut in part in the left-right direction. FIG. [Figure 13] 3 is a cross-sectional view of the drive unit of FIG. 2 cut in the left-right direction along the axis of a left drive shaft and a right drive shaft. FIG. [Figure 14] FIG. 3 is a perspective view of a left side cover and a baffle plate of the drive unit of FIG. 2. [Figure 15] 3 is a perspective view of the drive unit of FIG. 2, cut in the front-rear direction. FIG. [Figure 16] 3 is a cross-sectional view of a main part of a gear chamber of the drive unit of FIG. 2, taken along a cutaway in the front-rear direction. [Figure 17] 3 is a perspective view of a main part of a gear chamber of the drive unit of FIG. 2 with the right main case removed. FIG. [Figure 18] 3 is a perspective view of the drive unit of FIG. 2 with a right main case removed, the perspective view being cut partly in the left-right direction. FIG. [Figure 19] 3 is a perspective view of the drive unit of FIG. 2, cut in part in the left-right direction. FIG. [Figure 20] FIG. 3 is a perspective view of a right main case of the drive unit of FIG. 2. [Figure 21] 3 is a perspective view of a right main case and a right side cover of the drive unit in FIG. 2 cut in the left-right direction. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A vehicle equipped with a drive unit, which is one embodiment of the power transmission device of the present invention, will be described below with reference to the attached drawings. The drawings are to be viewed in the direction of the reference symbols. In this specification and the like, for the sake of simplicity and clarity, the front / rear, left / right, and up / down directions are described according to the direction as seen by the driver of the vehicle, and in the drawings, the front of the vehicle is indicated as Fr, the rear as Rr, the left as L, the right as R, the top as U, and the bottom as D.

[0012] [Overall vehicle configuration] As shown in Fig. 1, a vehicle V of this embodiment has a pair of left and right front wheels FW, a pair of left and right rear wheels RW, and a floor panel FP that constitutes the floor of the vehicle V. The vehicle V is partitioned into a passenger compartment CB and a front room FRM in front of the passenger compartment CB by a dash panel DP that extends in the vertical direction above the floor panel FP. A front seat FS and a rear seat RS are provided in the passenger compartment CB.

[0013] The vehicle V includes a drive unit 10 serving as a drive source, a battery pack IPU that stores power to be supplied to the drive unit 10, a charging and supplying control device CHGR that controls the input and output power of the battery pack IPU, a power receiving unit PR that can receive power from an external power source, a radiator 611 through which coolant R1 flows to cool a control device 50 (described later) of the drive unit 10, and a coolant pump 612 that pumps the coolant R1. The coolant R1 is, for example, a coolant called LLC (Long Life Coolant).

[0014] The drive unit 10 is disposed behind the rear seat RS and below the floor panel FP. The battery pack IPU is disposed under the floor of the vehicle compartment CB below the floor panel FP. The battery pack IPU houses a plurality of battery modules, each of which has a plurality of stacked battery cells. Each battery cell is a chargeable and dischargeable secondary battery, such as a lithium-ion battery or an all-solid-state battery.

[0015] The charging control device CHGR is accommodated in the front room FRM. The power receiving unit PR is provided on the upper surface of the front room FRM and is electrically connected to the charging control device CHGR. The radiator 611 is accommodated in the front room FRM and disposed near the front end of the front room FRM. The radiator 611 is a heat exchanger that cools the coolant R1 by exchanging heat between the coolant R1 flowing through it and external air caused by wind generated when the vehicle V is traveling. The coolant pump 612 is accommodated in the front room FRM.

[0016] [Overall configuration of drive unit] 2 and 3, the drive unit 10 includes a drive motor 20, a reduction gear 30 that reduces the speed of the power output from the drive motor 20 and outputs it to the outside, a power transmission chain 40 that transmits the power output from the drive motor 20 to the reduction gear 30, a control device 50 that controls the drive motor 20, an oil pump 621 that pumps motor cooling oil R2, and an oil cooler 63 that exchanges heat between cooling water R1 and the motor cooling oil R2. The motor cooling oil R2 is, for example, an oil called ATF (Automatic Transmission Fluid).

[0017] In the drive unit 10, the drive motor 20, the reduction gear 30, the power transmission chain 40, and the control device 50 are housed in a drive unit case 11. The oil pump 621 and the oil cooler 63 are attached to the left side surface of the drive unit case 11.

[0018] The drive motor 20 is a so-called inner rotor type motor that includes a drive shaft 21, a rotor 22 that is attached to the drive shaft 21 and rotates integrally with the drive shaft 21, and a stator 23 that is arranged radially opposite the rotor 22 with a small gap between them on the radial outside of the rotor 22.

[0019] In this embodiment, in the drive unit 10, the drive motor 20 is arranged so that the axial direction (i.e., the drive shaft 21) faces horizontally in the left-right direction. By arranging the drive shaft 21 so that it faces horizontally in this manner, the vertical dimension of the drive unit 10 can be made compact.

[0020] The stator 23 includes a stator core 231 and a coil 232 attached to the stator core 231 and configured with a plurality of windings of U-phase, V-phase, and W-phase.

[0021] The stator core 231 is configured by laminating a plurality of thin electromagnetic steel sheets, each having a substantially annular shape, in the axial direction.

[0022] The stator core 231 includes a yoke portion 231a having a substantially circular ring shape forming an outer ring portion of the stator core 231 as viewed in the axial direction, and a plurality of teeth portions 231b protruding radially from the inner peripheral surface of the yoke portion 231a toward the center. The teeth portions 231b are arranged at equal intervals along the circumferential direction of the stator core 231 as viewed in the axial direction. A slot portion 231c is formed between the teeth portions 231b adjacent to each other in the circumferential direction of the stator core 231. A plurality of slot portions 231c are formed at equal intervals along the circumferential direction of the stator core 231. Each of the teeth portions 231b and the slot portions 231c extends along the axial direction of the stator core 231.

[0023] The coil 232 is composed of a plurality of conductor segments inserted into the slots 231c of the stator core 231. The conductor segments are inserted into all of the slots 231c formed in the circumferential direction of the stator core 231.

[0024] Coil 232 has a left coil end portion 232L that protrudes axially outward from the left end face on one axial side of stator core 231, and a right coil end portion 232R that protrudes axially outward from the right end face on the other axial side of stator core 231.

[0025] A drive sprocket 21a around which a power transmission chain 40 is wound is attached to the left end of the drive shaft 21. The drive sprocket 21a rotates together with the drive shaft 21.

[0026] As shown in FIGS. 3 and 4, the reduction gear 30 includes a planetary gear mechanism 31 and a differential gear mechanism 32.

[0027] First, the planetary gear mechanism 31 will be described.

[0028] The planetary gear mechanism 31 has an input shaft 311 , a sun gear 312 , a plurality of planetary pinion shafts 313 , the same number of stepped pinions 314 as the planetary pinion shafts 313 , a planetary carrier 316 , and a ring gear 317 .

[0029] In this embodiment, the planetary gear mechanism 31 is arranged side by side in the front-rear direction behind the drive motor 20. The planetary gear mechanism 31 is arranged so that its axial direction (i.e., the input shaft 311) faces in the left-right direction parallel to the axial direction of the drive motor 20. The input shaft 311 of the planetary gear mechanism 31 is also arranged at a position at approximately the same height in the up-down direction as the drive shaft 21 of the drive motor 20. Furthermore, the outer diameter dimension of the planetary gear mechanism 31 is approximately the same as the outer diameter dimension of the drive motor 20, and the height of the drive unit 10 in the up-down direction is reduced.

[0030] The input shaft 311 is a hollow shaft, and a left drive shaft (described later) is inserted inside. A driven sprocket 311a around which the power transmission chain 40 is wound is attached to the left end of the input shaft 311. The driven sprocket 311a rotates integrally with the input shaft 311. The driven sprocket 311a has a larger diameter than the drive sprocket 21a attached to the drive shaft 21 of the drive motor 20, and the number of teeth of the driven sprocket 311a is greater than the number of teeth of the drive sprocket 21a.

[0031] The sun gear 312 is an external gear provided on the input shaft 311 and rotates integrally with the input shaft 311 on the same rotation axis.

[0032] The multiple planetary pinion shafts 313 are arranged radially outside the sun gear 312 at equal intervals in the circumferential direction along the outer circumferential surface of the sun gear 312 so as to face in the left-right direction parallel to the input shaft 311. In this embodiment, the four planetary pinion shafts 313 are arranged radially outside the sun gear 312 at 90 degree intervals in the circumferential direction of the input shaft 311.

[0033] A stepped pinion 314 having a first planetary gear 314a and a second planetary gear 314b that rotate integrally is rotatably supported on each planetary pinion shaft 313. In this embodiment, the first planetary gear 314a is disposed on the left side and the second planetary gear 314b is disposed on the right side of each planetary pinion shaft 313. Therefore, four first planetary gears 314a and four second planetary gears 314b are provided in an annular shape at 90 degree intervals along the circumferential direction of the input shaft 311.

[0034] First planetary gear 314a is an external gear that is disposed on the outer circumferential surface of sun gear 312 and meshes with sun gear 312. The four first planetary gears 314a are provided in an annular shape at 90 degree intervals along the outer circumferential surface of sun gear 312. Each of the four first planetary gears 314a meshes with the outer circumferential surface of sun gear 312.

[0035] The second planetary gear 314b is an external gear disposed on the inner circumferential surface of the ring gear 317 and meshes with the ring gear 317. The four second planetary gears 314b are provided in an annular shape at 90 degree intervals along the inner circumferential surface of the ring gear 317. In this embodiment, the second planetary gears 314b are external gears having a smaller diameter than the first planetary gear 314a.

[0036] The planetary carrier 316 connects the four planetary pinion shafts 313. The planetary carrier 316 is integral with the four planetary pinion shafts 313 and is rotatable about a rotation axis coaxial with the input shaft 311 (and the sun gear 312).

[0037] Therefore, the stepped pinion 314 having the first planetary gear 314a and the second planetary gear 314b can rotate about the planetary pinion shaft 313 and can revolve together with the planetary pinion shaft 313 on a rotation axis coaxial with the input shaft 311 (and the sun gear 312). The planetary carrier 316 rotates together with the orbital motion of the stepped pinion 314 on a rotation axis coaxial with the input shaft 311 (and the sun gear 312).

[0038] The ring gear 317 is disposed so as to surround the four second planetary gears 314b disposed in a circular shape, and is an annular internal gear whose inner circumferential surface meshes with each of the second planetary gears 314b. In this embodiment, the ring gear 317 is fixed to the drive unit case 11, and the ring gear 317 itself does not rotate.

[0039] Next, the differential gear mechanism 32 will be described.

[0040] The differential gear mechanism 32 includes a differential case 321, a differential pinion shaft 322 supported by the differential case 321, a first bevel gear 323a and a second bevel gear 323b rotatably supported on the differential pinion shaft 322, a left side gear 324L and a right side gear 324R meshing with the first bevel gear 323a and the second bevel gear 323b, and a left drive shaft 325L and a right drive shaft 325R.

[0041] The differential case 321 is formed integrally with the planetary carrier 316 of the planetary gear mechanism 31. Therefore, the differential case 321 rotates integrally with the planetary carrier 316 of the planetary gear mechanism 31 on a rotation axis coaxial with the input shaft 311. The differential case 321 includes an accommodating portion 321a that accommodates the differential pinion shaft 322, the first bevel gear 323a, the second bevel gear 323b, the left side gear 324L, and the right side gear 324R.

[0042] Differential pinion shaft 322 is housed in housing portion 321a of differential case 321 and supported by differential case 321. Differential pinion shaft 322 is disposed in housing portion 321a of differential case 321 so as to be perpendicular to the rotation axis of differential case 321. Differential pinion shaft 322 rotates integrally with differential case 321 about the rotation axis of differential case 321.

[0043] The first bevel gear 323a is housed in a housing portion 321a of the differential case 321, and is rotatably supported by the differential pinion shaft 322. The first bevel gear 323a has a generally truncated cone shape with an upper surface facing the rotation axis of the differential case 321, and a gear is formed on the side surface of the truncated cone.

[0044] The second bevel gear 323b is housed in the housing portion 321a of the differential case 321 and is rotatably supported by the differential pinion shaft 322 so as to face the first bevel gear 323a. The second bevel gear 323b has a generally truncated cone shape with an upper surface facing the rotation axis of the differential case 321, and a gear is formed on the side surface of the truncated cone.

[0045] The left side gear 324L is accommodated in the accommodation portion 321a of the differential case 321, and is disposed on the left side of the differential pinion shaft 322 between the first bevel gear 323a and the second bevel gear 323b. The rotation axis of the left side gear 324L is coaxial with the rotation axis of the differential case 321. The left side gear 324L has a generally truncated cone shape with the upper surface facing the differential pinion shaft 322 (i.e., to the right), and a gear is formed on the side surface of the truncated cone. The left side gear 324L meshes with both the first bevel gear 323a and the second bevel gear 323b.

[0046] The right side gear 324R is accommodated in the accommodation portion 321a of the differential case 321, and is disposed between the first bevel gear 323a and the second bevel gear 323b on the right side of the differential pinion shaft 322, facing the left side gear 324L in the left-right direction with the differential pinion shaft 322 in between. The rotation axis of the right side gear 324R is coaxial with the rotation axis of the differential case 321 and the rotation axis of the left side gear 324L. The right side gear 324R has a substantially truncated cone shape with the upper surface facing the differential pinion shaft 322 (i.e., leftward), and a gear is formed on the side surface of the truncated cone. The right side gear 324R meshes with both the first bevel gear 323a and the second bevel gear 323b.

[0047] The left drive shaft 325L passes through the hollow portion of the input shaft 311 of the planetary gear mechanism 31 and the center of the driven sprocket 311a, and extends in the left-right direction coaxially with the rotation axis of the input shaft 311 of the planetary gear mechanism 31 and the rotation axis of the differential case 321. The left drive shaft 325L has a left side gear 324L attached to its right end, and a left rear wheel RW attached to its left end. Therefore, the left side gear 324L, the left drive shaft 325L, and the left rear wheel RW rotate together.

[0048] The right drive shaft 325R extends in the left-right direction coaxially with the rotation axis of the input shaft 311 of the planetary gear mechanism 31, the rotation axis of the differential case 321, and the rotation axis of the left drive shaft 325L. The right drive shaft 325R has a right side gear 324R attached to its left end and a right rear wheel RW attached to its right end. Therefore, the right side gear 324R, the right drive shaft 325R, and the right rear wheel RW rotate together.

[0049] In this way, by forming the differential case 321 integrally with the planetary carrier 316 of the planetary gear mechanism 31, the planetary gear mechanism 31 and the differential gear mechanism 32 can be formed into an integral structure, and the reduction gear 30 can be made more compact.

[0050] Next, a power transmission path of the power output from the drive motor 20 will be described.

[0051] Power generated by the drive motor 20 is output from the drive shaft 21, and the drive sprocket 21a attached to the drive shaft 21 rotates integrally with the drive shaft 21. When the drive sprocket 21a rotates, the driven sprocket 311a rotates due to the power transmission chain 40 wound around the drive sprocket 21a and the driven sprocket 311a attached to the input shaft 311 of the planetary gear mechanism 31. The input shaft 311 of the planetary gear mechanism 31 rotates integrally with the driven sprocket 311a. At this time, since the number of teeth of the driven sprocket 311a is greater than the number of teeth of the drive sprocket 21a, the rotation of the drive shaft 21 is decelerated via the drive sprocket 21a, the power transmission chain 40, and the driven sprocket 311a, and is input to the input shaft 311 of the planetary gear mechanism 31.

[0052] In the planetary gear mechanism 31, power input to the input shaft 311 is transmitted to the stepped pinion 314 via the sun gear 312. The stepped pinion 314 rotates and revolves around its axis. The planetary carrier 316 rotates integrally with the revolution of the stepped pinion 314. In the planetary gear mechanism 31, since the ring gear 317 is fixed, the rotation of the input shaft 311 is reduced in speed at a predetermined reduction ratio and transmitted to the planetary carrier 316.

[0053] In the differential gear mechanism 32, the differential case 321 is formed integrally with the planetary carrier 316 of the planetary gear mechanism 31, and therefore rotates integrally with the rotation of the planetary carrier 316. Therefore, the power input to the input shaft 311 of the planetary gear mechanism 31 is reduced at a predetermined reduction ratio and input to the differential case 321 via the planetary carrier 316.

[0054] Therefore, the power output from the drive shaft 21 is input to the differential case 321 of the differential gear mechanism 32 via the power transmission chain 40 and the planetary gear mechanism 31, and the differential pinion shaft 322 revolves together with the differential case 321 around the rotation axis of the differential case 321.

[0055] When the vehicle V is moving straight, there is no difference in rotation between the left and right rear wheels RW, so the left side gear 324L and the right side gear 324R meshing with the first bevel gear 323a and the second bevel gear 323b rotate in response to the rotation of the differential pinion shaft 322. The left drive shaft 325L rotates together with the rotation of the left side gear 324L, causing the left rear wheel RW to rotate, and the right drive shaft 325R rotates together with the rotation of the right side gear 324R, causing the right rear wheel RW to rotate.

[0056] When the vehicle V is turning, the differential pinion shaft 322 revolves and the first bevel gear 323a and the second bevel gear 323b rotate so that the rotation speed of the rear wheel RW on the inside of the turn slows down and the rotation speed of the rear wheel RW on the outside of the turn increases, while the left side gear 324L and the right side gear 324R meshing with the first bevel gear 323a and the second bevel gear 323b rotate at different rotation speeds so that the rotation speed of the rear wheel RW on the inside of the turn slows down and the rotation speed of the rear wheel RW on the outside of the turn increases. Then, the left drive shaft 325L rotates together with the rotation of the left side gear 324L to rotate the left rear wheel RW, and the right drive shaft 325R rotates together with the rotation of the right side gear 324R to rotate the right rear wheel RW. Therefore, when the vehicle V is turning, the left drive shaft 325L and the right drive shaft 325R rotate so that the rotational speed of the rear wheel RW on the inside of the turn slows down and the rotational speed of the rear wheel RW on the outside of the turn increases.

[0057] In this manner, as shown by the arrows in FIG. 3, the power output from the drive motor 20 is decelerated via the drive sprocket 21a, the driven sprocket 311a, and the power transmission chain 40, and input to the reduction gear 30, where it is further decelerated by the planetary gear mechanism 31, and the power is appropriately distributed and transmitted to the left and right rear wheels RW by the differential gear mechanism 32.

[0058] Furthermore, by using the planetary gear mechanism 31 in the reduction mechanism, it is possible to obtain a desired reduction ratio while suppressing an increase in the radial dimension relative to the rotation axis direction.

[0059] Next, the drive unit case 11 will be described with reference to FIGS.

[0060] The drive unit case 11 has a main case 111, a left side cover 112 that covers the left side surface of the main case 111, and a right side cover 113 that covers the right side surface of the main case 111. The main case 111 is divided into two parts, a left main case 114 and a right main case 115.

[0061] The main case 111 is partitioned into a motor chamber 12 that houses the drive motor 20, a gear chamber 13 that houses the reduction gear 30, a chain chamber 14 that houses the power transmission chain 40, and a controller chamber 15 that houses the control device 50. The motor chamber 12 and the gear chamber 13 are formed side by side in the front-to-rear direction, with the motor chamber 12 at the front and the gear chamber 13 at the rear. The chain chamber 14 is formed on the left side of the motor chamber 12 and the gear chamber 13, and is open to the left. The controller chamber 15 is formed on the right side of the motor chamber 12 and the gear chamber 13, and is open to the right.

[0062] The left side cover 112 covers the left opening of the chain chamber 14. On the left side surface of the left side cover 112, an oil pump 621 and an oil cooler 63 are fixed.

[0063] 6 to 8, the left main case 114 forms the motor chamber 12, the gear chamber 13, and the chain chamber 14. The left main case 114 includes a first partition wall 114a that separates the motor chamber 12 from the chain chamber 14, and a second partition wall 114b that separates the motor chamber 12 from the gear chamber 13. The first partition wall 114a extends in the up-down direction and the front-rear direction between the drive sprocket 21a and the drive motor 20. The second partition wall 114b extends in the up-down direction and the left-right direction between the drive motor 20 and the reduction gear 30.

[0064] In the left main case 114, the motor chamber 12 is open to the right. In the left main case 114, the gear chamber 13 and the chain chamber 14 communicate with each other, but the left main case 114 is provided with a baffle plate 116 that separates the gear chamber 13 and the chain chamber 14 (see also FIG. 4). The baffle plate 116 extends in the up-down and front-rear directions between the driven sprocket 311a and the sun gear 312.

[0065] 9 and 10, the right main case 115 includes a right wall portion 123 covering the right opening of the motor chamber 12 formed in the left main case 114, and further includes a right wall portion 133 covering the right opening of the gear chamber 13 formed in the left main case 114, and a third partition wall 115a partitioning the motor chamber 12 and the gear chamber 13. The right main case 115 also forms a controller chamber 15 to the right of the right wall portion 123 including the front region of the right wall portion 133. In the right main case 115, the controller chamber 15 is open to the right.

[0066] The right side cover 113 covers the right opening of the controller chamber 15 .

[0067] (Temperature control system) 11, a temperature adjustment system 60 is configured in the vehicle V. The temperature adjustment system 60 includes a first temperature adjustment circuit 61 through which the above-mentioned cooling water R1 circulates and adjusts the temperature of the control device 50, a second temperature adjustment circuit 62 through which the above-mentioned motor cooling oil R2 circulates and adjusts the temperature and lubricates the drive motor 20, and the above-mentioned oil cooler 63. As described above, the oil cooler 63 exchanges heat between the cooling water R1 circulating in the first temperature adjustment circuit 61 and the motor cooling oil R2 circulating in the second temperature adjustment circuit 62.

[0068] In the first temperature control circuit 61, the cooling water R1 circulates through the cooling water pump 612, the control device 50, the oil cooler 63, and the radiator 611. The cooling water R1 pumped from the cooling water pump 612 is supplied to the control device 50 to control the temperature of the control device 50, is supplied from the control device 50 to the oil cooler 63, exchanges heat with the motor cooling oil R2 flowing in the second temperature control circuit 62, is supplied to the radiator 611, is cooled by heat exchange with the outside air, and returns to the cooling water pump 612.

[0069] In the second temperature control circuit 62, the motor cooling oil R2 circulates through the oil pump 621, the drive motor 20, and the oil cooler 63. A reservoir 622 is formed inside the drive unit case 11 to temporarily store the motor cooling oil R2 cooled by the oil cooler 63. The motor cooling oil R2 temporarily stored in the reservoir 622 is pumped from the oil pump 621 and supplied to the inside of the drive unit case 11 to control the temperature of the drive motor 20. The motor cooling oil R2 is supplied from the drive unit case 11 to the oil cooler 63 and cooled by heat exchange with the cooling water R1 flowing through the first temperature control circuit 61, and then flows into the reservoir 622 and is temporarily stored in the reservoir 622 again.

[0070] (Gear and chain chamber lubrication and cooling)

[0071] Next, lubrication and cooling of the gear chamber 13 and the chain chamber 14 will be described with reference to FIGS.

[0072] As shown in Fig. 12 to Fig. 14, the gear chamber 13 and the chain chamber 14 separated by the baffle plate 116 store a common fluid, lubricating oil R3. The lubricating oil R3 is, for example, an oil called ATF (Automatic Transmission Fluid). The lubricating oil R3 may be the same oil as the motor cooling oil R2, but does not mix with the motor cooling oil R2 circulating through the second temperature control circuit 62. The lubricating oil R3 lubricates the reduction gear 30 provided in the gear chamber 13, the drive sprocket 21a, the driven sprocket 311a, the power transmission chain 40, and the like provided in the chain chamber 14.

[0073] Specifically, in the chain chamber 14, the lower part of the driven sprocket 311a is immersed in the lubricating oil R3 stored in the lower part of the chain chamber 14 (see FIG. 13). The lubricating oil R3 stored in the lower part of the chain chamber 14 is scooped up by the driven sprocket 311a, and the drive sprocket 21a, the driven sprocket 311a, the power transmission chain 40, and the like provided in the chain chamber 14 are lubricated and cooled by the lubricating oil R3 scooped up by the driven sprocket 311a.

[0074] Therefore, the higher the level of the lubricating oil R3 in the chain chamber 14, the more efficiently the driven sprocket 311a scoops it up.

[0075] In the gear chamber 13, the lubricating oil R3 scooped up by the driven sprocket 311a in the chain chamber 14 is supplied to the gear chamber 13 through the inside of the input shaft 311. The reduction gear 30 is lubricated and cooled by the lubricating oil R3 supplied from the chain chamber 14.

[0076] Specifically, a plurality of oil supply holes 311b penetrating in the radial direction are formed along the axial direction in the outer peripheral wall of the hollow input shaft 311. The lubricating oil R3 supplied to the inside of the hollow input shaft 311 is discharged from the oil supply holes 311b toward the radially outward direction by the centrifugal force caused by the rotation of the input shaft 311. The lubricating oil R3 discharged toward the radially outward direction from the oil supply holes 311b lubricates and cools the planetary gear mechanism 31. On the other hand, the lubricating oil R3 not discharged from the oil supply holes 311b flows from the left to the right in the axial direction inside the input shaft 311 and is discharged from the right end of the input shaft 311. The lubricating oil R3 discharged from the right end of the input shaft 311 is supplied to the differential gear mechanism 32 and lubricates and cools the differential gear mechanism 32.

[0077] Therefore, by increasing the amount of lubricating oil R3 discharged from the oil supply hole 311b of the hollow input shaft 311, it is possible to sufficiently lubricate and cool the reduction gear 30 even if the liquid level of the lubricating oil R3 in the gear chamber 13 is lowered. Therefore, by increasing the amount of lubricating oil R3 discharged from the oil supply hole 311b of the hollow input shaft 311 and lowering the liquid level of the lubricating oil R3 in the gear chamber 13, the agitation resistance that agitates the lubricating oil R3 due to the rotation of the reduction gear 30 becomes smaller, and loss during rotation of the reduction gear 30 decreases.

[0078] In this way, it is desirable that the liquid level of the lubricating oil R3 in the chain chamber 14 be high, and that the liquid level of the lubricating oil R3 in the gear chamber 13 be low.

[0079] The gear chamber 13 is formed with an accommodation chamber 130 in which the planetary gear mechanism 31 and the differential gear mechanism 32 are accommodated. The accommodation chamber 130 has a substantially circular cross section as viewed from the direction of the rotation axis of the planetary gear mechanism 31 and the differential gear mechanism 32. A part of the lubricating oil R3 supplied from the chain chamber 14 to the gear chamber 13 through the inside of the input shaft 311 is stored in the lower part of the accommodation chamber 130. The lower part of the planetary gear mechanism 31 and the lower part of the differential gear mechanism 32 are immersed in the lubricating oil R3 stored in the lower part of the accommodation chamber 130 (see FIG. 13). The lubricating oil R3 stored in the lower part of the accommodation chamber 130 is scooped up by the rotation of the planetary gear mechanism 31 and the differential gear mechanism 32, and the lubricating oil R3 scooped up by the rotation of the planetary gear mechanism 31 and the differential gear mechanism 32 also lubricates and cools the planetary gear mechanism 31 and the differential gear mechanism 32.

[0080] In this embodiment, as described above, the gear chamber 13 and the chain chamber 14 communicate with each other in the left main case 114, but the left main case 114 is provided with a baffle plate 116 that separates the gear chamber 13 and the chain chamber 14. The baffle plate 116 extends between the driven sprocket 311a and the sun gear 312 in the up-down and front-rear directions.

[0081] The baffle plate 116 extends upward from the bottom of the chain chamber 14 and the gear chamber 13, and restricts the movement of the lubricating oil R3 between the chain chamber 14 and the gear chamber 13.

[0082] This allows the liquid level of the lubricating oil R3 in the chain chamber 14 to be different from the liquid level of the lubricating oil R3 in the gear chamber 13, making it possible to increase the liquid level of the lubricating oil R3 in the chain chamber 14 and decrease the liquid level of the lubricating oil R3 in the gear chamber 13. Therefore, the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear 30 can be reduced while improving the lubricating performance in the gear chamber 13 and the chain chamber 14.

[0083] In this embodiment, the liquid level of the lubricating oil R3 in the chain chamber 14 and the liquid level of the lubricating oil R3 in the gear chamber 13 are different.

[0084] This allows the liquid level of the lubricating oil R3 in the chain chamber 14 and the liquid level of the lubricating oil R3 in the gear chamber 13 to be individually set to optimal levels.

[0085] In this embodiment, the liquid level of the lubricating oil R3 in the gear chamber 13 is lower than the liquid level of the lubricating oil R3 in the chain chamber .

[0086] As a result, the lubrication performance in the gear chamber 13 and the chain chamber 14 can be improved, while the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear 30 can be reduced.

[0087] Baffle plate 116 is a plate-like member having a circular opening 116a in the center. Input shaft 311 is inserted through opening 116a. As described above, input shaft 311 is provided with sun gear 312, and driven sprocket 311a is attached to the left of sun gear 312.

[0088] In this way, the baffle plate 116 not only separates the lower part of the chain chamber 14 and the gear chamber 13, but also extends radially outward around the input shaft 311. This not only makes it possible to make the liquid level of the lubricating oil R3 in the chain chamber 14 different from the liquid level of the lubricating oil R3 in the gear chamber 13, but also makes it possible to restrict the movement of the lubricating oil R3 scattered by the rotation of the driven sprocket 311a and the reduction gear 30 between the chain chamber 14 and the gear chamber 13.

[0089] In this embodiment, the planetary gear mechanism 31 rotates counterclockwise when viewed from the left. Since the ring gear 317 is fixed to the drive unit case 11, the sun gear 312 rotates counterclockwise when viewed from the left, and the first planetary gear 314a meshing with the sun gear 312 and the second planetary gear 314b formed integrally with the first planetary gear 314a and meshing with the ring gear 317 revolve counterclockwise when viewed from the left while rotating clockwise when viewed from the left.

[0090] 15 to 19, an upper space 131 is formed above the gear chamber 13. The upper space 131 is formed between the motor chamber 12 and the accommodation chamber 130 of the gear chamber 13. The upper space 131 is formed inside the accommodation chamber 130 and communicates with the accommodation chamber 130. The upper space 131 is formed in a wall portion of the drive unit case 11 on the rotation direction side (the front side in this embodiment) of the upper end of the input shaft 311, that is, in the second partition wall 114b in this embodiment.

[0091] A lower space 132 is formed in the lower part of the gear chamber 13. The lower space 132 is partitioned as a separate room from the accommodation chamber .

[0092] The lower space 132 is formed below the upper space 131. The lower space 132 is formed between the motor chamber 12 and the accommodation chamber 130 of the gear chamber 13. The upper space 131 and the lower space 132 are separated by an upper and lower partition wall 114c extending rearward from the second partition wall 114b.

[0093] The upper space 131 and the lower space 132 are formed between the motor chamber 12 and the accommodation chamber 130 of the gear chamber 13, and both of them store the lubricating oil R3.

[0094] This makes it possible to provide the upper space 131 and the lower space 132 while preventing the vertical dimension of the drive unit case 11 from becoming large. By storing the lubricating oil R3 in the upper space 131 and the lower space 132, the liquid level of the lubricating oil R3 stored in the lower part of the accommodation chamber 130 can be lowered, so that the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear 30 can be further reduced.

[0095] On the other hand, the motor cooling oil R2 is prevented from flowing into the upper space 131 and the lower space 132.

[0096] As a result, the lubricating oil R3 and the motor cooling oil R2 do not mix, so that the contamination levels of the lubricating oil R3 and the motor cooling oil R2 are different, and it is possible to prevent the lubricating oil R3, which tends to contain a lot of sludge, from being supplied to the drive motor 20.

[0097] The motor chamber 12 has a generally circular cross section when viewed from the direction of the output rotation shaft of the drive motor 20. The accommodation chamber 130 has a generally circular cross section when viewed from the direction of the output rotation shaft of the reduction gear 30.

[0098] When viewed in the direction of the rotational axis of the drive motor 20, the planetary gear mechanism 31, and the differential gear mechanism 32, i.e., from the left to right direction, the upper space 131 is located between the motor chamber 12 and the accommodation chamber 130 and is formed in the upper area of ​​the rotational shaft of the drive motor 20 and the rotational shafts of the planetary gear mechanism 31 and the differential gear mechanism 32, and the lower space 132 is located between the motor chamber 12 and the accommodation chamber 130 and is formed in the lower area of ​​the rotational shaft of the drive motor 20 and the rotational shafts of the planetary gear mechanism 31 and the differential gear mechanism 32.

[0099] This makes it possible to effectively utilize the space between the motor chamber 12 and the accommodating chamber 130 in the direction of the output rotation shaft of the drive motor 20 and the reduction gear 30, i.e., when viewed from the left-right direction, in the upper and lower regions of the output rotation shaft of the drive motor 20 and the reduction gear 30, while preventing the vertical dimensions of the drive unit case 11 from becoming large, and to provide an upper space 131 and a lower space 132 that serve as storage areas for storing lubricating oil R3.

[0100] Both the upper space 131 and the lower space 132 are formed so that at least a portion of them overlap with the motor chamber 12 and the accommodating chamber 130 when viewed from the direction of a virtual straight line VL1 (the front-to-rear direction in this embodiment) that is perpendicular to the output rotation shaft of the drive motor 20 and the output rotation shaft of the reduction gear 30.

[0101] This makes it possible to reduce the projected area of ​​the drive unit case 11 as viewed from the direction of the imaginary straight line VL1 (the front-rear direction in this embodiment), thereby making it possible to reduce the size of the drive unit case 11.

[0102] In particular, in this embodiment, the upper space 131 and the lower space 132 are both formed so that more than half of their projected area as viewed from the direction of the virtual straight line VL1 (the front-to-rear direction in this embodiment) overlaps with the motor chamber 12 and the accommodation chamber 130.

[0103] This makes it possible to reduce the projected area of ​​the drive unit case 11 as viewed from the direction of the imaginary straight line VL1 (the front-rear direction in this embodiment), thereby making it possible to make the drive unit case 11 more compact.

[0104] The upper space 131 extends in the axial direction of the output rotating shaft of the reduction gear 30, and is partitioned in the axial direction of the output rotating shaft of the reduction gear 30 into a planetary side upper storage portion 131a and a differential side upper storage portion 131b.

[0105] The lower space 132 extends in the axial direction of the output rotating shaft of the reduction gear 30, and is partitioned in the axial direction of the output rotating shaft of the reduction gear 30 into a differential-side lower storage chamber 132a and a planetary-side lower storage chamber 132b.

[0106] In this way, by forming the upper space 131 and the lower space 132 so as to be long in the axial direction of the output rotating shaft of the reduction gear transmission 30 and dividing the space into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear transmission 30, it is possible to lengthen the time that the lubricating oil R3 stays in the upper space 131. This makes it possible to eliminate bubbles in the lubricating oil R3 and to lower the temperature of the lubricating oil R3.

[0107] Moreover, the upper space 131, that is, the planetary side upper storage portion 131a and the differential side upper storage portion 131b are integrally formed by casting in the drive unit case 11 (in this embodiment, the left main case 114).

[0108] Similarly, the lower space 132, that is, the differential-side lower storage chamber 132a and the planetary-side lower storage chamber 132b are integrally formed by casting in the drive unit case 11 (in this embodiment, the left main case 114).

[0109] This makes it possible to form the upper space 131 and the lower space 132, more specifically, the planetary side upper storage section 131a, the differential side upper storage section 131b, the differential side lower storage chamber 132a, and the planetary side lower storage chamber 132b, at low cost.

[0110] The planetary-side upper storage portion 131a is provided above the rotation axis of the input shaft 311 and below the upper end of the planetary gear mechanism 31 in the vertical direction, at a position where at least a portion of the storage portion 131a overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311. The position where at least a portion of the storage portion 131a overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311 refers to a position where at least a portion of the storage portion 131a overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311 when viewed from a predetermined direction radially outside the input shaft 311 toward the center of the input shaft 311.

[0111] In the planetary-side upper reservoir 131a, a portion of the lubricating oil R3 that is scooped up and scattered from the lower part of the accommodation chamber 130 by the planetary gear mechanism 31 is collected and stored.

[0112] In addition, a portion of the lubricating oil R3 that is discharged radially outward from the oil supply hole 311b of the input shaft 311 and scattered is collected and stored in the planetary-side upper storage portion 131a.

[0113] As a result, the lubricating oil R3 discharged radially outward from the oil supply hole 311b of the input shaft 311 and scattered, and the lubricating oil R3 scooped up and scattered by the planetary gear mechanism 31 are collected in the planetary-side upper reservoir 131a, thereby making it possible to lower the liquid level of the lubricating oil R3 stored in the lower part of the accommodation chamber 130, thereby making it possible to reduce the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear 30. In this way, the height dimension of the drive unit 10 can be reduced without reducing the power transmission efficiency.

[0114] The differential-side upper storage portion 131b is provided above the rotation axis of the differential case 321 and below the upper end of the differential case 321 in the vertical direction, at a position where at least a portion of the storage portion 131b overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321. The position where at least a portion of the storage portion 131b overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321 refers to a position where at least a portion of the storage portion 131b overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321 when viewed from a predetermined direction radially outside the differential case 321 toward the rotation axis center of the differential case 321.

[0115] In the differential-side upper reservoir 131b, a portion of the lubricating oil R3 that is scooped up and scattered from the lubricating oil R3 stored in the lower part of the gear chamber 13 by the differential gear mechanism 32 including the differential case 321 is collected and stored.

[0116] In addition, the differential-side upper reservoir 131b collects and stores a portion of the lubricating oil R3 that is discharged from the right end of the input shaft 311 toward the differential gear mechanism 32 and scattered by the rotation of the differential gear mechanism 32.

[0117] As a result, the lubricating oil R3 discharged from the right end of the input shaft 311 toward the differential gear mechanism 32 and scattered by the rotation of the differential gear mechanism 32, and the lubricating oil R3 scooped up from the bottom of the storage chamber 130 by the differential gear mechanism 32 including the differential case 321 and scattered, are collected in the differential side upper storage section 131b. This makes it possible to lower the liquid level of the lubricating oil R3 stored in the bottom of the storage chamber 130, and thereby reduce the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear device 30.

[0118] In the left main case 114, the planetary side upper storage portion 131a and the differential side upper storage portion 131b are adjacent to each other in the rotational axis direction of the planetary gear mechanism 31 and the differential gear mechanism 32, with an upper partition wall 114d in between. The upper partition wall 114d is provided with a first oil circulation hole 134a that communicates between the planetary side upper storage portion 131a and the differential side upper storage portion 131b and through which the lubricating oil R3 flows.

[0119] This allows the lubricating oil R3 stored in the planetary-side upper reservoir 131a to flow into the differential-side upper reservoir 131b.

[0120] Furthermore, the height of a bottom surface 131a1 of the planetary-side upper storage portion 131a is higher than the height of a bottom surface 131b1 of the differential-side upper storage portion 131b.

[0121] This allows the lubricating oil R3 stored in the planetary-side upper reservoir 131a to easily flow to the differential-side upper reservoir 131b.

[0122] In addition, in the left main case 114, a first air vent 135a is provided in the upper partition wall 114d above the first oil circulation hole 134a. The first air vent 135a connects the planetary side upper storage portion 131a and the differential side upper storage portion 131b and allows gas to flow between the planetary side upper storage portion 131a and the differential side upper storage portion 131b.

[0123] This prevents the pressure in the planetary side upper reservoir 131a and the differential side upper reservoir 131b from increasing due to the gas in the planetary side upper reservoir 131a and the differential side upper reservoir 131b, thereby preventing the lubricating oil R3 stored in the planetary side upper reservoir 131a from becoming difficult to flow to the differential side upper reservoir 131b.

[0124] The differential-side lower storage chamber 132a is provided below the differential-side upper storage portion 131b. In the left main case 114, the differential-side upper storage portion 131b and the differential-side lower storage chamber 132a are adjacent to each other in the vertical direction with the above-mentioned upper and lower partition walls 114c in between. That is, the upper and lower partition walls 114c form the bottom wall of the differential-side upper storage portion 131b and the upper wall of the differential-side lower storage chamber 132a. The upper and lower partition walls 114c are provided with a second oil circulation hole 134b that communicates between the differential-side upper storage portion 131b and the differential-side lower storage chamber 132a and through which the lubricating oil R3 flows.

[0125] As mentioned above, at the bottom of the gear chamber 13, the lower space 132 is partitioned off as a separate chamber from the accommodating chamber 130, and the differential side lower storage chamber 132a is also a separate chamber from the accommodating chamber 130. Therefore, the lubricating oil R3 flows from the planetary side upper storage chamber 131a to the differential side upper storage chamber 131b, and the lubricating oil R3 stored in the differential side upper storage chamber 131b does not flow into the accommodating chamber 130, but instead flows through the second oil circulation hole 134b to the differential side lower storage chamber 132a, which is a separate chamber from the accommodating chamber 130.

[0126] This allows the liquid level of the lubricating oil R3 stored in the accommodation chamber 130 to be kept lower, so that the stirring resistance of the lubricating oil R3 when the reduction gear 30 rotates can be made smaller.

[0127] As shown in FIG. 19, the left main case 114 and the right main case 115 are assembled with a gasket 136 sandwiched therebetween. The gasket 136 is a plate-shaped member extending in the up-down and front-rear directions. The differential-side upper storage portion 131b is formed on the left side of the gasket 136, and the wall portion of the differential-side upper storage portion 131b is formed by the left main case 114 and the gasket 136. The gasket 136 forms at least a part of the right wall of the differential-side upper storage portion 131b. A breather chamber 137 is formed on the right side of the gasket 136 adjacent to the differential-side upper storage portion 131b with the gasket 136 sandwiched therebetween, and the wall portion of the breather chamber 137 is formed by the right main case 115 and the gasket 136. The gasket 136 forms at least a part of the left wall of the breather chamber 137.

[0128] This makes it possible to form the wall of the differential-side upper reservoir 131b and the breather chamber 137 at low cost and while suppressing an increase in weight.

[0129] The gasket 136 is provided with an oil circulation hole 136a that communicates between the differential-side upper storage portion 131b and the breather chamber 137 and through which the remaining lubricating oil R3 that does not flow to the second oil circulation hole 134b passes out of the lubricating oil R3 stored in the differential-side upper storage portion 131b. Furthermore, the gasket 136 is provided with a communication hole 136b above the oil circulation hole 136a that communicates between the differential-side upper storage portion 131b and the breather chamber 137 and through which the gas in the differential-side upper storage portion 131b and the breather chamber 137 and the mist of the lubricating oil R3 pass.

[0130] This makes it possible to easily form the oil circulation hole 136a and the communication hole 136b that communicate between the differential-side upper reservoir 131b and the breather chamber 137.

[0131] 20, a breather hole 137a communicating with the outside of the drive unit case 11 is provided at the upper part of the breather chamber 137. When the pressure in the gear chamber 13 exceeds a predetermined pressure, gas is released from the breather hole 137a, and the pressure in the gear chamber 13 is maintained at or below the predetermined pressure.

[0132] In addition, in the flow direction of the lubricating oil R3 inside the drive unit case 11, the breather chamber 137 and the breather hole 137a are provided after passing through the planetary side upper reservoir 131a and the differential side upper reservoir 131b in which the lubricating oil R3 is stored. This allows the breather chamber 137 and the breather hole 137a to be formed in a recessed portion of the drive unit case 11, thereby preventing contamination such as external dirt and water from being mixed into the lubricating oil R3. Furthermore, since the breather chamber 137 and the breather hole 137a can be formed in a position far from heat sources such as the drive motor 20 and the reduction gear 30, it is also possible to prevent the lubricating oil R3 from thermally expanding and blowing out to the outside of the drive unit case 11.

[0133] As shown in FIGS. 20 and 21, the drive unit case 11 (in this embodiment, the right main case 115) is provided with a right drive shaft bearing 115b that supports the right drive shaft 325R.

[0134] A breather drain hole 137b is provided at the bottom of the breather chamber 137 to discharge the lubricating oil R3 that has entered the breather chamber 137 from the differential-side upper reservoir 131b through the oil circulation hole 136a and the lubricating oil R3 that has entered the breather chamber 137 from the differential-side upper reservoir 131b through the communication hole 136b, condensed in the breather chamber 137 to become liquid, and stored in the lower part of the breather chamber 137. The breather drain hole 137b communicates the breather chamber 137 with the accommodation chamber 130, and the drive unit case 11 (the right main case 115 in this embodiment) is provided with an oil guide portion 115c that guides the lubricating oil R3 that has flowed out from the breather drain hole 137b into the accommodation chamber 130 to the right drive shaft bearing 115b.

[0135] As a result, the lubricating oil R3 that condenses and liquefies inside the breather chamber 137 and accumulates in the lower part of the breather chamber 137 can be discharged through the breather drain hole 137b, and the right drive shaft bearing 115b can be lubricated with the lubricating oil R3 discharged from the breather drain hole 137b. Therefore, the lubricating oil R3 accumulated in the lower part of the breather chamber 137 can be used to efficiently lubricate the right drive shaft bearing 115b.

[0136] Furthermore, the lubricating oil R3 that condenses and becomes liquid inside the breather chamber 137 and accumulates in the lower part of the breather chamber 137 can be discharged from the breather chamber 137 and returned to the accommodation chamber .

[0137] In this embodiment, the oil guide portion 115c has a gutter shape extending from the right main case 115 and is integrally molded with the right main case 115 by casting, and the opening surface of the oil guide portion 115c is covered by a plate-shaped side member.

[0138] This makes it possible to form the oil guide portion 115c at low cost.

[0139] Returning to FIG. 15 to FIG. 19, the planetary-side lower storage chamber 132b is provided adjacent to the left side of the differential-side lower storage chamber 132a. In the left main case 114, the differential-side lower storage chamber 132a and the planetary-side lower storage chamber 132b are adjacent to each other in the left-right direction with the lower partition wall 114e in between. That is, the lower partition wall 114e forms the left wall of the differential-side lower storage chamber 132a and the right wall of the planetary-side lower storage chamber 132b. The lower partition wall 114e is provided with a third oil circulation hole 134c that communicates between the differential-side lower storage chamber 132a and the planetary-side lower storage chamber 132b and through which the lubricating oil R3 flows.

[0140] As mentioned above, at the bottom of the gear chamber 13, the lower space 132 is partitioned off as a separate chamber from the accommodation chamber 130, and the planetary side lower storage chamber 132b is also a separate chamber from the accommodation chamber 130. Therefore, the lubricating oil R3 that flows into the differential side lower storage chamber 132a does not flow into the accommodation chamber 130, but flows through the third oil circulation hole 134c to the planetary side lower storage chamber 132b, which is a separate chamber from the accommodation chamber 130.

[0141] This allows the liquid level of the lubricating oil R3 stored in the accommodation chamber 130 to be kept lower, so that the stirring resistance of the lubricating oil R3 when the reduction gear 30 rotates can be made smaller.

[0142] In addition, since the lubricating oil R3 flows from the differential-side lower storage chamber 132a through the third oil circulation hole 134c to the planetary-side lower storage chamber 132b, the movement speed of the lubricating oil R3 from the differential-side lower storage chamber 132a to the planetary-side lower storage chamber 132b can be slowed down by setting the diameter of the third oil circulation hole 134c to be small. This lengthens the movement time of the lubricating oil R3 from the differential-side lower storage chamber 132a to the planetary-side lower storage chamber 132b, making it possible to break up more air bubbles in the lubricating oil R3 and lower the temperature of the lubricating oil R3.

[0143] In addition, in the left main case 114, a second air hole 135b is provided in the lower partition wall 114e above the third oil circulation hole 134c, which connects the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b and allows gas to circulate within the interior of the differential side lower storage chamber 132a and the interior of the planetary side lower storage chamber 132b.

[0144] This prevents the pressure inside the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b from increasing due to the gas inside the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b, thereby preventing the lubricating oil R3 stored in the differential side lower storage chamber 132a from flowing easily into the planetary side lower storage chamber 132b.

[0145] Furthermore, the height of a bottom surface 132a1 of the differential-side lower storage chamber 132a is higher than the height of a bottom surface 132b1 of the planetary-side lower storage chamber 132b.

[0146] This allows the lubricating oil R3 stored in the differential-side lower storage chamber 132a to easily flow to the planetary-side lower storage chamber 132b.

[0147] At least a portion of the left wall of the planetary-side lower storage chamber 132b is formed by the above-mentioned baffle plate 116. Therefore, the planetary-side lower storage chamber 132b and the chain chamber 14 are partitioned by the baffle plate 116.

[0148] This makes it possible to form the planetary-side lower storage chamber 132b at low cost and while suppressing an increase in weight.

[0149] The baffle plate 116 is provided with an oil discharge hole 116b that communicates between the planetary-side lower storage chamber 132b and the chain chamber 14 and through which the lubricating oil R3 flows.

[0150] Therefore, the lubricating oil R3 supplied from the chain chamber 14 through the inside of the input shaft 311 to the gear chamber 13 lubricates and cools the reduction gear 30 and is stored in the accommodating chamber 130, is scooped up by the rotation of the reduction gear 30, and a portion of it is collected in the planetary side upper reservoir 131a and the differential side upper reservoir 131b, flows through the differential side upper reservoir 131b, the differential side lower reservoir 132a, and the planetary side lower reservoir 132b, and then returns to the chain chamber 14 through the oil drain hole 116b.

[0151] In this manner, the oil drain hole 116b for discharging the lubricating oil R3 that has circulated within the gear chamber 13 from the gear chamber 13 can be easily formed.

[0152] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiment may be arbitrarily combined within the scope of the invention.

[0153] This specification describes at least the following items. In parentheses, components corresponding to the above-described embodiment are shown as examples, but the present invention is not limited to these.

[0154] (1) a drive motor (drive motor 20); a reduction gear (reduction gear 30) that reduces the power of the drive motor and outputs it; a drive unit case (drive unit case 11) that houses the drive motor and the reduction gear; A drive unit (drive unit 10) comprising: an output rotation shaft of the drive motor and an output rotation shaft of the reduction gear device are arranged parallel to each other and aligned in a horizontal direction, The drive unit case includes: a motor chamber (motor chamber 12) in which the drive motor is housed; a gear chamber (gear chamber 13) provided with an accommodation chamber (accommodation chamber 130) for accommodating the reduction gear; The motor chamber and the gear chamber are separated by a partition wall (second partition wall 114b), Between the motor chamber and the accommodation chamber, an upper space (upper space 131) and a lower space (lower space 132) separated vertically by upper and lower partition walls (upper and lower partition walls 114c) extending from the partition wall are formed. Drive unit.

[0155] According to (1), the vertical dimension of the drive unit case can be prevented from becoming large, and an upper space and a lower space can be provided in the drive unit case.

[0156] (2) A drive unit according to (1), the motor chamber has a substantially circular cross section as viewed from a direction of an output rotation shaft of the drive motor, The housing has a substantially circular cross section as viewed in a direction of the output rotation axis of the reduction gear device. Drive unit.

[0157] According to (2), when viewed from the direction of the output shaft of the drive motor and the reduction gear device, the space between the motor chamber and the storage chamber, above and below the output shaft of the drive motor and the reduction gear device, can be effectively utilized, and upper and lower spaces can be provided while preventing the vertical dimensions of the drive unit case from becoming large.

[0158] (3) A drive unit according to (1), The upper space and the lower space are formed so as to at least partially overlap with the motor chamber and the accommodation chamber when viewed from a direction of a virtual line (virtual line VL1) perpendicular to the output rotation shaft of the drive motor and the output rotation shaft of the reduction gear device. Drive unit.

[0159] According to (3), the projected area of ​​the drive unit case as viewed from the imaginary straight line direction can be reduced, so that the drive unit case can be made compact.

[0160] (4) A drive unit according to (1), The upper space and the lower space are formed such that, when viewed from a direction of a virtual line (virtual line VL1) perpendicular to the output rotation shaft of the drive motor and the output rotation shaft of the reduction gear device, half or more of the projected area viewed from the virtual line direction overlaps with the motor chamber and the accommodation chamber. Drive unit.

[0161] According to (4), the projected area of ​​the drive unit case as viewed from the imaginary straight line can be made smaller, so that the drive unit case can be made more compact.

[0162] (5) A drive unit according to (1), The upper space and the lower space store a lubricating liquid (lubricating oil R3) that lubricates the reduction gear device. Drive unit.

[0163] According to (5), by storing the lubricating liquid in the upper space and the lower space, the liquid level of the lubricating liquid stored in the lower part of the accommodating chamber can be lowered, thereby making it possible to reduce the stirring resistance of the lubricating liquid caused by the rotation of the reduction gear device.

[0164] (6) A drive unit according to (5), The motor cooling liquid (motor cooling oil R2) that cools the drive motor does not flow into the upper space and the lower space. Drive unit.

[0165] According to (6), since the lubricating fluid that lubricates the reduction gear device and the motor coolant that cools the drive motor do not mix, the contamination levels of the lubricating fluid and the motor coolant are separated, and it is possible to prevent lubricating fluid, which is likely to contain a lot of sludge, from being supplied to the drive motor.

[0166] (7) A drive unit according to (1), the upper space and the lower space are integrally formed with the drive unit case by casting. Drive unit.

[0167] According to (7), the upper space and the lower space can be formed at low cost.

[0168] (8) A drive unit according to (5), The upper space and the lower space extend in the axial direction of the output rotation shaft of the reduction gear device. Drive unit.

[0169] According to (8), by forming the upper space and the lower space to be long in the axial direction of the output rotating shaft of the reduction gear device, the time for which the lubricating liquid stored in the upper space and the lower space remains in the upper space and the lower space can be increased, thereby making it possible to suppress foaming of the lubricating liquid and to lower the temperature of the lubricating liquid.

[0170] (9) A drive unit according to (8), The upper space and the lower space are partitioned into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear device. Drive unit.

[0171] According to (9), since the upper space and the lower space are partitioned into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear device, the lubricating liquid stored in the upper space and the lower space can be retained for a longer period of time in the upper space and the lower space, which can further suppress foaming of the lubricating liquid and further reduce the temperature of the lubricating liquid.

[0172] (10) A drive unit according to (1), The reduction gear device has a planetary gear mechanism (planetary gear mechanism 31). Drive unit.

[0173] According to (10), by the reduction gear transmission having a planetary gear mechanism, it is possible to obtain a desired reduction ratio while suppressing an increase in the radial dimension of the reduction gear transmission with respect to the rotation axis direction.

[0174] (11) A drive unit according to (10), The reduction gear device has a differential gear mechanism (differential gear mechanism 32), The input rotating shaft of the planetary gear mechanism and the output rotating shaft of the differential gear mechanism are coaxial. Drive unit.

[0175] According to (11), by arranging the input shaft of the planetary gear mechanism and the output shaft of the differential gear mechanism coaxially, the reduction gear can be made more compact.

[0176] (12) A drive unit according to (11), The planetary gear mechanism includes a sun gear (sun gear 312), a plurality of planetary gears (stepped pinions 314), a planetary carrier (planetary carrier 316), and a ring gear (ring gear 317). The power input to the planetary gear mechanism is output from the planetary carrier, The planetary carrier and the differential case (differential case 321) of the differential gear mechanism are integrally formed. Drive unit.

[0177] According to (12), by forming the planetary carrier and the differential case integrally, the planetary gear mechanism and the differential gear mechanism can be formed as an integral structure, and the reduction gear can be made more compact. [Explanation of symbols]

[0178] 10 Drive unit 11 Drive unit case 114b Second Compartment Wall (Compartment Wall) 114c Upper and lower partition walls 12 Motor Room 13 Gear Room 130 Containment Room 131 Upper space 132 Lower space 20 Drive motor 30 Reducer 31 Planetary gear mechanism 312 Sun Gear 314 Step pinion (planetary gear) 316 Planetary Carrier 317 Ring Gear 32 Differential gear mechanism 321 Differential Case R2 Motor cooling oil (motor coolant) R3 Lubricating oil (lubricating fluid) VL1 Virtual line

Claims

1. A drive motor; a reduction gear device that reduces the power of the drive motor and outputs the reduced power; a drive unit case that houses the drive motor and the reduction gear; A drive unit comprising: an output rotation shaft of the drive motor and an output rotation shaft of the reduction gear device are arranged parallel to each other and aligned in a horizontal direction, The drive unit case includes: a motor chamber in which the drive motor is accommodated; a gear chamber having an accommodation chamber for accommodating the reduction gear device; The motor chamber and the gear chamber are partitioned by a partition wall, Between the motor chamber and the accommodation chamber, an upper space and a lower space are formed which are separated vertically by upper and lower partition walls extending from the partition wall. Drive unit.

2. 2. A drive unit according to claim 1, the motor chamber has a substantially circular cross section as viewed from a direction of an output rotation shaft of the drive motor, The housing has a substantially circular cross section as viewed in a direction of the output rotation axis of the reduction gear device. Drive unit.

3. 2. A drive unit according to claim 1, the upper space and the lower space are formed so as to at least partially overlap with the motor chamber and the accommodation chamber when viewed from a direction of a virtual straight line perpendicular to an output rotation shaft of the drive motor and an output rotation shaft of the reduction gear device. Drive unit.

4. 2. A drive unit according to claim 1, the upper space and the lower space are formed such that, when viewed from a virtual straight line direction perpendicular to the output rotation shaft of the drive motor and the output rotation shaft of the reduction gear device, half or more of the projected area viewed from the virtual straight line direction overlaps with the motor chamber and the accommodation chamber. Drive unit.

5. 2. A drive unit according to claim 1, The upper space and the lower space store lubricating liquid that lubricates the reduction gear transmission. Drive unit.

6. A drive unit according to claim 5, A motor coolant for cooling the drive motor does not flow into the upper space and the lower space. Drive unit.

7. 2. A drive unit according to claim 1, the upper space and the lower space are integrally formed with the drive unit case by casting. Drive unit.

8. A drive unit according to claim 5, The upper space and the lower space extend in the axial direction of the output rotation shaft of the reduction gear device. Drive unit.

9. A drive unit according to claim 8, The upper space and the lower space are partitioned into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear device. Drive unit.

10. 2. A drive unit according to claim 1, The reduction gear has a planetary gear mechanism. Drive unit.

11. A drive unit according to claim 10, The reduction gear transmission has a differential gear mechanism, The input rotating shaft of the planetary gear mechanism and the output rotating shaft of the differential gear mechanism are coaxial. Drive unit.

12. A drive unit according to claim 11, The planetary gear mechanism includes a sun gear, a plurality of planetary gears, a planetary carrier, and a ring gear. The power input to the planetary gear mechanism is output from the planetary carrier, The planetary carrier and the differential case of the differential gear mechanism are integrally formed. Drive unit.

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