Drive unit

Abstract

The invention provides a drive unit capable of forming a space in a drive unit housing while suppressing an increase in the vertical size. A drive unit (10) is provided with: a drive motor (20); a reduction gear (30); and a drive unit case (11) that accommodates the drive motor and the reduction gear. An output rotating shaft of the driving motor and an output rotating shaft of the speed reduction device are parallel to each other and are arranged in the horizontal direction. The drive unit housing has: a motor chamber (12) in which the drive motor is housed; and a gear chamber (13) provided with a housing chamber (130) for housing the reduction gear. The motor chamber (12) and the gear chamber (13) are partitioned 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 accommodating chamber (130).

Description

Technical Field

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

[0002] In recent years, efforts to realize a low-carbon society or a decarbonized society have been actively carried out, and research related to electrification technology has been conducted in order to reduce CO2 emissions and improve energy efficiency in vehicles.

[0003] In vehicle electrification technology, in order to increase the degree of freedom of installation in the vehicle, the drive unit is required to be miniaturized, especially the height dimension is required to be suppressed. In addition, in order to improve power consumption and cruising range, it is required to transmit power efficiently.

[0004] For example, Patent Document 1 describes a drive unit in which a space for storing lubricating oil is formed in a drive unit case to improve lubrication performance.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2004-180477 Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, in the drive unit described in Patent Document 1, since a space for storing lubricating oil is formed above the drive gear of the main shaft provided on the speed reducer, there is a problem that the vertical dimension of the drive unit becomes large.

[0010] The present invention provides a drive unit capable of forming a space in a drive unit housing while suppressing an increase in the vertical dimensions.

[0011] Solutions to Solve Problems

[0012] The present invention relates to a driving unit, comprising:

[0013] A driving motor;

[0014] a reduction gear, which is used to reduce the speed of output power of the driving motor; and

[0015] a drive unit housing that accommodates the drive motor and the reduction gear,

[0016] in,

[0017] The output rotating shaft of the driving motor and the output rotating shaft of the reduction gear are parallel to each other and arranged in a horizontal direction.

[0018] The drive unit housing has:

[0019] a motor chamber that accommodates the driving motor; and

[0020] The gear chamber is provided with a receiving chamber for receiving the reduction gear.

[0021] The motor chamber and the gear chamber are divided by a partition wall.

[0022] An upper space and a lower space separated vertically by upper and lower partition walls extending from the partition wall are formed between the motor room and the storage room.

[0023] Effects of the Invention

[0024] According to the present invention, it is possible to form an upper space and a lower space in the drive unit case while suppressing an increase in the vertical dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of a vehicle equipped with a drive unit according to an embodiment of the present invention, as viewed from the left.

[0026] Figure 2 This is a perspective view showing a partially cutaway view of a drive unit according to an embodiment of the present invention.

[0027] Figure 3 It is used to illustrate Figure 2 A partially cutaway stereoscopic view of a power transmission path in a drive unit.

[0028] Figure 4 yes Figure 2 Skeleton diagram of the reduction gear in the drive unit.

[0029] Figure 5 yes Figure 2 Top and left side views of the drive unit.

[0030] Figure 6 Observed from the left Figure 2 A perspective view of the left main housing of the drive unit.

[0031] Figure 7 yes Figure 5 AA line section view.

[0032] Figure 8 Observed from the right Figure 2 A perspective view of the left main housing of the drive unit.

[0033] Fig. 9 Observed from the left Figure 2 A perspective view of the right main housing of the drive unit.

[0034] Fig.10 yes Figure 5 BB line cross-sectional view.

[0035] Fig.11 yes Figure 2 Block diagram of the temperature control system in the drive unit.

[0036] Fig.12 Yes Figure 2 A stereoscopic view showing a portion of a drive unit cut away from each other along the left-right direction.

[0037] Fig.13 Yes Figure 2 A cross-sectional view of the drive unit cut along the axis of the left drive shaft and the right drive shaft in the left and right directions for observation.

[0038] Fig.14 yes Figure 2 A perspective view of the left side cover and baffle of the drive unit.

[0039] Fig.15 Yes Figure 2 A stereoscopic view showing a portion of a drive unit cut away along the front-to-back direction.

[0040] Fig.16 Yes Figure 2 A sectional view of a main portion of a gear chamber in which a portion of a drive unit is observed by cutting along the front-rear direction.

[0041] Fig.17 Remove the right main housing. Figure 2 A perspective view of the main parts of the gear chamber of the drive unit for observation.

[0042] Fig.18 The right main housing is removed. Figure 2 A stereoscopic view showing a portion of a drive unit cut away from each other along the left-right direction.

[0043] Fig.19 Yes Figure 2 A stereoscopic view showing a portion of a drive unit cut away from each other along the left-right direction.

[0044] Fig. 20 yes Figure 2 A perspective view of the right main housing of the drive unit.

[0045] Fig.21 Yes Figure 2 A stereoscopic view showing a portion of a right main housing and a right side cover of a drive unit cut along the left-right direction for observation.

[0046] Description of reference numerals:

[0047] 10 drive units

[0048] 11Driver unit housing

[0049] 114b Second partition wall (partition wall)

[0050] 114c Upper and lower dividing walls

[0051] 12 Motor room

[0052] 13 Gear Room

[0053] Containment Chamber 130

[0054] 131 Upper Space

[0055] 132 Lower Space

[0056] 20 Driving motor

[0057] 30 reduction gear

[0058] 31 Planetary gear mechanism

[0059] 312 sun gear

[0060] 314 stepped pinion (planetary gear)

[0061] 316 planet carrier

[0062] 317 ring gear

[0063] 32 Differential gear mechanism

[0064] 321 differential housing

[0065] R2 motor cooling oil (motor coolant)

[0066] R3 lubricant (lubricant)

[0067] VL1 imaginary straight line. DETAILED DESCRIPTION

[0068] Hereinafter, a vehicle equipped with a drive unit as an embodiment of the power transmission device of the present invention will be described based on the accompanying drawings. In addition, the accompanying drawings are viewed along the directions indicated by the accompanying drawings. In addition, in this specification, etc., in order to make the description simple and clear, the front and rear, left and right, and up and down directions are described according to the directions observed from the driver of the vehicle. In the accompanying drawings, the front of the vehicle is represented as Fr, the rear is represented as Rr, the left is represented as L, the right is represented as R, the top is represented as U, and the bottom is represented as D.

[0069]

Overall structure of the vehicle

[0070] like Figure 1As shown, the 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 bottom panel FP constituting the bottom surface of the vehicle V. The vehicle V is divided into a vehicle compartment CB and a front cabin FRM in front thereof by a front control panel DP extending in the up-down direction above the bottom panel FP. Front seats FS and rear seats RS are provided in the vehicle compartment CB.

[0071] The vehicle V includes a drive unit 10 as a drive source, a battery pack IPU storing power supplied to the drive unit 10, a charging and supply control device CHGR controlling input and output power of the battery pack IPU, a power receiving unit PR capable of receiving power from an external power source, a radiator 611 for circulating cooling water R1 for cooling a control device 50 described later of the drive unit 10, and a cooling water pump 612 for pressurizing and conveying the cooling water R1. The cooling water R1 is, for example, cooling water called LLC (Long Life Coolant).

[0072] The drive unit 10 is arranged below the floor panel FP behind the rear seat RS. The battery pack IPU is arranged below the bottom surface of the vehicle compartment CB below the floor panel FP. The battery pack IPU accommodates a plurality of battery modules in which a plurality of cells are stacked. Each cell is a secondary battery capable of charge and discharge, such as a lithium-ion battery or an all-solid-state battery.

[0073] The charging and power supply control device CHGR is accommodated in the front compartment FRM. The power receiving unit PR is provided on the upper surface of the front compartment FRM and is electrically connected to the charging and power supply control device CHGR. The radiator 611 is accommodated in the front compartment FRM and is arranged near the front end in the front compartment FRM. The radiator 611 is a heat exchanger that cools the cooling water R1 by heat exchange between the external air brought by the running wind of the vehicle V and the circulating cooling water R1. The cooling water pump 612 is accommodated in the front compartment FRM.

[0074] [Overall structure of the drive unit]

[0075] like Figure 2 and Figure 3 As shown, the drive unit 10 includes a drive motor 20, a reduction gear 30 that reduces 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 pressurizes and delivers motor cooling oil R2, and an oil cooler 63 that performs heat exchange between cooling water R1 and motor cooling oil R2. The motor cooling oil R2 is, for example, an oil called ATF (Automatic Transmission Fluid; automatic transmission oil).

[0076] In the drive unit 10, the drive motor 20, the reduction gear 30, the power transmission chain 40, and the control device 50 are accommodated in the drive unit case 11. The oil pump 621 and the oil cooler 63 are mounted on the left side surface of the drive unit case 11.

[0077] The driving motor 20 is a so-called inner rotor type motor, which includes a driving shaft 21, a rotor 22 mounted on the driving shaft 21 and rotating integrally with the driving shaft 21, and a stator 23 arranged to be radially opposed to the rotor 22 with a small gap radially outside the rotor 22.

[0078] In this embodiment, the drive motor 20 is arranged in the drive unit 10 with its axial direction (ie, the drive shaft 21) oriented horizontally in the left-right direction. Thus, by arranging the drive shaft 21 oriented horizontally, the vertical dimension of the drive unit 10 can be made compact.

[0079] The stator 23 includes a stator core 231 and a coil 232 mounted on the stator core 231 and composed of a plurality of windings such as a U-phase, a V-phase, and a W-phase.

[0080] The stator core 231 is formed by laminating a plurality of thin electromagnetic steel plates having a substantially annular shape in the axial direction.

[0081] The stator core 231 includes a yoke 231a that forms a substantially annular shape of the outer ring portion of the stator core 231 when viewed from the axial direction, and a plurality of teeth 231b that protrude radially from the inner circumferential surface of the yoke 231a toward the center. The plurality of teeth 231b are arranged at equal intervals along the circumferential direction of the stator core 231 when viewed from the axial direction. A groove 231c is formed between adjacent teeth 231b in the circumferential direction of the stator core 231. A plurality of grooves 231c are formed at equal intervals along the circumferential direction of the stator core 231. Each tooth 231b and groove 231c extends along the axial direction of the stator core 231.

[0082] The coil 232 is composed of a plurality of conductor segments inserted into the slots 231 c of the stator core 231 . The conductor segments are inserted into all of the slots 231 c formed in a plurality along the circumferential direction of the stator core 231 .

[0083] The coil 232 has a left coil end 232L protruding axially outward from a left end surface on one axial side of the stator core 231 , and a right coil end 232R protruding axially outward from a right end surface on the other axial side of the stator core 231 .

[0084] A drive sprocket 21a around which a power transmission chain 40 is wound is attached to the left end portion of the drive shaft 21. The drive sprocket 21a rotates integrally with the drive shaft 21.

[0085] like Figure 3 and Figure 4 As shown, the reduction gear device 30 includes a planetary gear mechanism 31 and a differential gear mechanism 32 .

[0086] First, the planetary gear mechanism 31 will be described.

[0087] The planetary gear mechanism 31 includes an input shaft 311 , a sun gear 312 , a plurality of planetary pinion shafts 313 , the same number of stepped pinion gears 314 as the planetary pinion shafts 313 , a planetary carrier 316 , and a ring gear 317 .

[0088] In the present embodiment, the planetary gear mechanism 31 is arranged in the front-to-back direction behind the driving motor 20. The planetary gear mechanism 31 is arranged so that the axial direction (i.e., the input shaft 311) is parallel to the axial direction of the driving motor 20 and faces the left-right direction. In addition, the input shaft 311 of the planetary gear mechanism 31 is arranged at a position at substantially the same height as the driving shaft 21 of the driving motor 20 in the vertical direction. In addition, the outer diameter of the planetary gear mechanism 31 is substantially the same as the outer diameter of the driving motor 20, and the height of the driving unit 10 in the vertical direction is low.

[0089] The input shaft 311 is a hollow shaft, and the left drive shaft described later passes through the inside of the input shaft 311. A driven sprocket 311a around which the power transmission chain 40 is wound is mounted at the left end of the input shaft 311. The driven sprocket 311a rotates integrally with the input shaft 311. The diameter of the driven sprocket 311a is larger than the diameter of the drive sprocket 21a mounted on 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.

[0090] 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.

[0091] A plurality of pinion shafts 313 are arranged at equal intervals in the circumferential direction on the radially outer side of the sun gear 312 along the outer circumferential surface of the sun gear 312 in a manner parallel to the input shaft 311 and oriented in the left-right direction. In the present embodiment, four pinion shafts 313 are arranged at 90-degree intervals in the circumferential direction on the radially outer side of the sun gear 312 along the circumferential direction of the input shaft 311.

[0092] The stepped pinion 314 having the first planetary gear 314a and the second planetary gear 314b that rotate integrally is supported on each planetary pinion shaft 313 in a manner that allows free rotation. In the present embodiment, the first planetary gear 314a is arranged on the left side and the second planetary gear 314b is arranged on the right side on each planetary pinion shaft 313. Therefore, four first planetary gears 314a and four second planetary gears 314b are provided in a circular ring shape at intervals of 90 degrees along the circumference of the input shaft 311.

[0093] The first planetary gears 314a are external gears disposed on the outer circumference of the sun gear 312 and meshing with the sun gear 312. The four first planetary gears 314a are arranged in an annular shape at 90-degree intervals along the outer circumference of the sun gear 312. The four first planetary gears 314a mesh with the outer circumference of the sun gear 312, respectively.

[0094] The second planetary gears 314b are external gears disposed on the inner circumference of the ring gear 317 and meshing with the ring gear 317. Four second planetary gears 314b are arranged in an annular shape at 90 degree intervals along the inner circumference of the ring gear 317. In this embodiment, the second planetary gears 314b are external gears with a smaller diameter than the first planetary gears 314a.

[0095] The planetary carrier 316 is connected to the four planetary pinion shafts 313. The planetary carrier 316 and the four planetary pinion shafts 313 are integrally rotatable on a rotation axis coaxial with the input shaft 311 (and the sun gear 312).

[0096] Therefore, the stepped pinion 314 having the first planetary gear 314a and the second planetary gear 314b freely rotates about the planetary pinion shaft 313, and freely revolves on a rotation axis coaxial with the input shaft 311 (and the sun gear 312) in an integrated manner with the planetary pinion shaft 313. Furthermore, the planet carrier 316 rotates on a rotation axis coaxial with the input shaft 311 (and the sun gear 312) in an integrated manner with the revolving motion of the stepped pinion 314.

[0097] The ring gear 317 is an annular internal gear disposed so as to surround the four annularly disposed second planetary gears 314b and whose inner peripheral surface meshes with each second planetary gear 314b. In the present embodiment, the ring gear 317 is fixed to the drive unit case 11 and does not rotate.

[0098] Next, the differential gear mechanism 32 will be described.

[0099] 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 by 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.

[0100] 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 a housing portion 321a that houses the differential pinion shaft 322, the first bevel gear 323a, the second bevel gear 323b, the left gear 324L, and the right gear 324R.

[0101] The differential pinion shaft 322 is accommodated in the accommodating portion 321a of the differential case 321 and is supported by the differential case 321. The differential pinion shaft 322 is arranged in the accommodating portion 321a of the differential case 321 in a manner orthogonal to the rotation axis of the differential case 321. The differential pinion shaft 322 rotates integrally with the differential case 321 about the rotation axis of the differential case 321.

[0102] The first bevel gear 323a is accommodated in the accommodating portion 321a of the differential case 321 and is rotatably supported by the differential pinion shaft 322. The first bevel gear 323a has a substantially truncated cone shape with its upper surface facing the rotation axis of the differential case 321, and a gear is formed on the side surface of the truncated cone.

[0103] The second bevel gear 323b is accommodated in the accommodating portion 321a of the differential case 321, and is rotatably supported by the differential pinion shaft 322 in a manner opposite to the first bevel gear 323a. The second bevel gear 323b has a substantially truncated cone shape with its upper surface facing the rotation axis of the differential case 321, and a gear is formed on the side of the truncated cone.

[0104] The left side gear 324L is accommodated in the accommodating portion 321a of the differential case 321, and is arranged between the first bevel gear 323a and the second bevel gear 323b on the left side of the differential pinion shaft 322. 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 substantially truncated cone shape with the upper surface facing the differential pinion shaft 322 (i.e., the right direction), and a gear is formed on the side of the truncated cone. Moreover, the left side gear 324L is meshed with both the first bevel gear 323a and the second bevel gear 323b.

[0105] The right side gear 324R is accommodated in the accommodating portion 321a of the differential case 321, and is arranged between the first bevel gear 323a and the second bevel gear 323b on the right side of the differential pinion shaft 322 in a manner that the left side gear 324L is opposite to the differential pinion shaft 322 in the left-right direction. 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., the left direction), and a gear is formed on the side of the truncated cone. Moreover, the right side gear 324R is meshed with both the first bevel gear 323a and the second bevel gear 323b.

[0106] 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 gear 324L mounted on the right end, and a left rear wheel RW mounted on the left end. Therefore, the left gear 324L, the left drive shaft 325L, and the left rear wheel RW rotate integrally.

[0107] 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 gear 324R mounted on the left end, and a right rear wheel RW mounted on the right end. Therefore, the right gear 324R, the right drive shaft 325R, and the right rear wheel RW rotate integrally.

[0108] In this way, the differential case 321 is formed integrally with the carrier 316 of the planetary gear mechanism 31 , so that the planetary gear mechanism 31 and the differential gear mechanism 32 can be integrally structured, and the reduction gear device 30 can be further reduced in size.

[0109] Next, a power transmission path of the power output from the driving motor 20 will be described.

[0110] The power generated by the driving motor 20 is output from the driving shaft 21, and the driving sprocket 21a installed on the driving shaft 21 rotates integrally with the driving shaft 21. Moreover, when the driving sprocket 21a rotates, the driven sprocket 311a rotates due to the power transmission chain 40 wound on the driving sprocket 21a and the driven sprocket 311a installed on the input shaft 311 of the planetary gear mechanism 31. Moreover, the input shaft 311 of the planetary gear mechanism 31 rotates integrally with the driven sprocket 311a. At this time, the number of teeth of the driven sprocket 311a is greater than the number of teeth of the driving sprocket 21a, so the rotation of the driving shaft 21 is decelerated via the driving 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.

[0111] In the planetary gear mechanism 31, the power input to the input shaft 311 is transmitted to the stepped pinion 314 via the sun gear 312. And, the stepped pinion 314 rotates while revolving. And, the planet carrier 316 rotates integrally with the revolving 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 decelerated at a predetermined reduction ratio and transmitted to the planet carrier 316.

[0112] 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 thus 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 in speed at a predetermined reduction ratio and input to the differential case 321 via the planetary carrier 316.

[0113] 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 about the rotation axis of the differential case 321 .

[0114] When the vehicle V is traveling straight, there is no rotation difference 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 accordance with the rotation of the differential pinion shaft 322. In addition, the left drive shaft 325L rotates integrally with the rotation of the left side gear 324L, thereby rotating the left rear wheel RW, and the right drive shaft 325R rotates integrally with the rotation of the right side gear 324R, thereby rotating the right rear wheel RW.

[0115] When the vehicle V turns, the differential pinion shaft 322 revolves, and the first bevel gear 323a and the second bevel gear 323b rotate to slow down the rotation speed of the rear wheel RW on the inner side of the turn and speed up the rotation speed of the rear wheel RW on the outer side of the turn, and 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 to slow down the rotation speed of the rear wheel RW on the inner side of the turn and speed up the rotation speed of the rear wheel RW on the outer side of the turn. Moreover, the left drive shaft 325L rotates integrally with the rotation of the left side gear 324L, thereby rotating the rear wheel RW on the left side, and the right drive shaft 325R rotates integrally with the rotation of the right side gear 324R, thereby rotating the rear wheel RW on the right side. Therefore, when the vehicle V turns, the left drive shaft 325L and the right drive shaft 325R rotate in a manner that slows down the rotation speed of the rear wheel RW on the inner side of the turn and speeds up the rotation speed of the rear wheel RW on the outer side of the turn.

[0116] In this way, Figure 3 As shown by the arrow, the power output from the driving motor 20 is decelerated and input into the reduction device 30 via the driving sprocket 21a, the driven sprocket 311a and the power transmission chain 40, 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.

[0117] Furthermore, by using the planetary gear mechanism 31 as the speed reduction mechanism, it is possible to obtain a desired speed reduction ratio while suppressing an increase in the radial dimension relative to the rotation axis direction.

[0118] Next, refer to Figures 5 to 10 The drive unit case 11 will be described.

[0119] The drive unit case 11 includes a main case 111, a left cover 112 covering the left side of the main case 111, and a right cover 113 covering the right side of the main case 111. The main case 111 is divided into a left main case 114 and a right main case 115.

[0120] The main housing 111 is divided into a motor chamber 12 for accommodating a driving motor 20, a gear chamber 13 for accommodating a reduction gear 30, a chain chamber 14 for accommodating a power transmission chain 40, and a controller chamber 15 for accommodating a control device 50. The motor chamber 12 and the gear chamber 13 are arranged side by side in the front-to-back 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 on 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 on the right.

[0121] The left side cover 112 covers the opening on the left side of the chain chamber 14. To the left side surface of the left side cover 112, an oil pump 621 and an oil cooler 63 are fixed.

[0122] like Figures 6 to 8 As shown, 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 partitions the motor chamber 12 and the chain chamber 14, and a second partition wall 114b that partitions the motor chamber 12 and 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.

[0123] The left main housing 114 has an opening on the right side of the motor chamber 12. In addition, in the left main housing 114, the gear chamber 13 is connected to the chain chamber 14, and a baffle 116 is provided in the left main housing 114 to separate the gear chamber 13 and the chain chamber 14 (see also Figure 4 The baffle plate 116 extends between the driven sprocket 311 a and the sun gear 312 in the up-down direction and the front-rear direction.

[0124] like Fig. 9 and Fig.10 As shown, the right main housing 115 includes a right wall portion 123 covering an opening on the right side of the motor chamber 12 formed in the left main housing 114, and the right main housing 115 also includes a right wall portion 133 covering an opening on the right side of the gear chamber 13 formed in the left main housing 114, and a third partition wall 115a partitioning the motor chamber 12 and the gear chamber 13. In addition, the right main housing 115 forms a controller chamber 15 on the right side of the right wall portion 123 including the front side area of ​​the right wall portion 133. In the right main housing 115, the right side of the controller chamber 15 is open.

[0125] The right side cover 113 covers the opening on the right side of the controller room 15 .

[0126] (Temperature Control System)

[0127] like Fig.11 As shown, a temperature control system 60 is configured in the vehicle V. The temperature control system 60 includes a first temperature control circuit 61 through which the cooling water R1 mentioned above circulates and controls the temperature of the control device 50, a second temperature control circuit 62 through which the motor cooling oil R2 mentioned above circulates and controls the temperature and lubricates the drive motor 20, and the oil cooler 63 mentioned above. As mentioned above, the oil cooler 63 performs heat exchange between the cooling water R1 circulated in the first temperature control circuit 61 and the motor cooling oil R2 circulated in the second temperature control circuit 62.

[0128] 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 under pressure from the cooling water pump 612 is supplied to the control device 50 to control the temperature of the control device 50, supplied from the control device 50 to the oil cooler 63 to perform heat exchange with the motor cooling oil R2 flowing in the second temperature control circuit 62, supplied to the radiator 611, cooled by heat exchange with the outside air, and returned to the cooling water pump 612.

[0129] 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. In addition, a storage portion 622 for temporarily storing the motor cooling oil R2 cooled by the oil cooler 63 is formed inside the drive unit housing 11. The motor cooling oil R2 temporarily stored in the storage portion 622 is pressurized and transported from the oil pump 621, and is supplied to the inside of the drive unit housing 11 to control the temperature of the drive motor 20. Moreover, the motor cooling oil R2 is supplied from the drive unit housing 11 to the oil cooler 63 and is cooled by heat exchange with the cooling water R1 flowing in the first temperature control circuit 61, and then flows into the storage portion 622 and is temporarily stored in the storage portion 622 again.

[0130] (Lubrication and cooling of gear and chain chambers)

[0131] Next, refer to Figures 12 to 21 The lubrication and cooling of the gear chamber 13 and the chain chamber 14 will be described.

[0132] like Figure 12 to Figure 14 As shown, in the gear chamber 13 and the chain chamber 14 separated by the baffle 116, a lubricating oil R3 as a common fluid is stored. 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 it is not mixed with the motor cooling oil R2 circulating in the second temperature control circuit 62. The lubricating oil R3 lubricates the reduction gear 30 provided in the gear chamber 13, the driving sprocket 21a provided in the chain chamber 14, the driven sprocket 311a, and the power transmission chain 40.

[0133] Specifically, in the chain chamber 14, the lower portion of the driven sprocket 311a is immersed in the lubricating oil R3 stored in the lower portion of the chain chamber 14 (see Fig.13 ). Moreover, the lubricating oil R3 stored in the lower part of the chain chamber 14 is carried up by the driven sprocket 311a, and the lubricating oil R3 carried up by the driven sprocket 311a lubricates and cools the driving sprocket 21a, the driven sprocket 311a, the power transmission chain 40, etc. provided in the chain chamber 14.

[0134] Therefore, the higher the liquid level of the lubricating oil R3 in the chain chamber 14 is, the higher the pulling efficiency of the driven sprocket 311 a can be.

[0135] In the gear chamber 13, the lubricating oil R3 taken 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. Then, the reduction gear 30 is lubricated and cooled by the lubricating oil R3 supplied from the chain chamber 14.

[0136] Specifically, a plurality of oil supply holes 311b penetrating in the radial direction are formed in the axial direction on 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 radially outward from the oil supply hole 311b by the centrifugal force generated by the rotation of the input shaft 311. Moreover, the lubricating oil R3 discharged radially outward from the oil supply hole 311b lubricates and cools the planetary gear mechanism 31. On the other hand, the lubricating oil R3 not discharged from the oil supply hole 311b flows axially from left to right inside the input shaft 311 and is discharged from the right end portion of the input shaft 311. Moreover, the lubricating oil R3 discharged from the right end portion of the input shaft 311 is supplied to the differential gear mechanism 32 to lubricate and cool the differential gear mechanism 32.

[0137] Therefore, even if the height of the liquid level of the lubricating oil R3 in the gear chamber 13 is lowered by increasing the lubricating oil R3 discharged from the oil supply hole 311b of the hollow input shaft 311, the reduction gear 30 can be sufficiently lubricated and cooled. Therefore, regarding the case where the height of the liquid level of the lubricating oil R3 in the gear chamber 13 is lowered by increasing the lubricating oil R3 discharged from the oil supply hole 311b of the hollow input shaft 311, the stirring resistance of the lubricating oil R3 by the rotation of the reduction gear 30 becomes smaller, and the loss when the reduction gear 30 rotates is reduced.

[0138] Thus, it is desirable that the liquid level of the lubricating oil R3 in the chain chamber 14 be high, and it is desirable that the liquid level of the lubricating oil R3 in the gear chamber 13 be low.

[0139] In addition, the gear chamber 13 is formed with a housing chamber 130 for housing the planetary gear mechanism 31 and the differential gear mechanism 32. The cross section of the housing chamber 130 viewed from the rotation axis direction of the planetary gear mechanism 31 and the differential gear mechanism 32 has a substantially circular shape. A portion 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 portion of the housing chamber 130. The lower portion of the planetary gear mechanism 31 and the lower portion of the differential gear mechanism 32 are immersed in the lubricating oil R3 stored in the lower portion of the housing chamber 130 (see FIG. 1 ). Fig.13). Moreover, the lubricating oil R3 stored in the lower part of the storage chamber 130 is brought up by the rotation of the planetary gear mechanism 31 and the differential gear mechanism 32, and is also lubricated and cooled by the lubricating oil R3 brought up by the rotation of the planetary gear mechanism 31 and the differential gear mechanism 32.

[0140] In this embodiment, as described above, the gear chamber 13 and the chain chamber 14 are connected in the left main case 114, and a baffle plate 116 is provided in the left main case 114 to separate 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 vertical direction and the front-rear direction.

[0141] Furthermore, the baffle plate 116 extends upward from the bottom of the chain chamber 14 and the gear chamber 13 , and restricts the flow of the lubricating oil R3 between the chain chamber 14 and the gear chamber 13 .

[0142] Thus, the liquid level of the lubricating oil R3 in the chain chamber 14 can be made different from the liquid level of the lubricating oil R3 in the gear chamber 13, and the liquid level of the lubricating oil R3 in the chain chamber 14 can be increased while the liquid level of the lubricating oil R3 in the gear chamber 13 can be decreased. Therefore, the lubrication performance in the gear chamber 13 and the chain chamber 14 can be improved and the stirring resistance of the lubricating oil R3 generated by the rotation of the reduction gear 30 can be reduced.

[0143] In the present embodiment, the height of the liquid level of the lubricating oil R3 in the chain chamber 14 is different from the height of the liquid level of the lubricating oil R3 in the gear chamber 13 .

[0144] Thereby, the height of the liquid level of the lubricating oil R3 in the chain chamber 14 and the height of the liquid level of the lubricating oil R3 in the gear chamber 13 can be respectively set to the optimal height.

[0145] Furthermore, in the present 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 14 .

[0146] This can improve the lubrication performance in the gear chamber 13 and the chain chamber 14 and reduce the stirring resistance of the lubricating oil R3 caused by the rotation of the reduction gear device 30 .

[0147] The baffle plate 116 is a plate-shaped member having a circular opening 116a at the center. The input shaft 311 passes through the opening 116a. As described above, the input shaft 311 is provided with the sun gear 312, and the driven sprocket 311a is mounted on the left side of the sun gear 312.

[0148] In this way, the baffle 116 not only separates the lower part of the chain chamber 14 and the gear chamber 13, but also extends radially outward with the input shaft 311 as the center. Therefore, in addition to making the height of the liquid level of the lubricating oil R3 in the chain chamber 14 different from the height of the liquid level of the lubricating oil R3 in the gear chamber 13, it is also possible to limit the lubricating oil R3 scattered due to the rotation of the driven sprocket 311a and the reduction device 30 from flowing between the chain chamber 14 and the gear chamber 13.

[0149] In the present embodiment, the planetary gear mechanism 31 rotates counterclockwise when viewed from the left. Furthermore, the ring gear 317 is fixed to the drive unit housing 11, so that 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 rotate clockwise when viewed from the left, and revolve counterclockwise when viewed from the left.

[0150] like Figures 15 to 19 As shown, an upper space 131 is formed in the upper part of the gear chamber 13. The upper space 131 is formed between the motor chamber 12 and the housing chamber 130 of the gear chamber 13. The upper space 131 is formed in the housing chamber 130 and communicates with the housing chamber 130. The upper space 131 is formed in the wall portion of the drive unit housing 11 on the rotation direction side (the front side in this embodiment) of the upper end of the input shaft 311, that is, the second partition wall 114b in this embodiment.

[0151] A lower space 132 is formed in the lower portion of the gear chamber 13 . The lower space 132 is partitioned into a chamber different from the accommodating chamber 130 .

[0152] The lower space 132 is formed below the upper space 131. The lower space 132 is formed between the motor chamber 12 and the accommodating chamber 130 of the gear chamber 13. The upper space 131 and the lower space 132 are separated by the upper and lower partition walls 114c extending rearward from the second partition wall 114b.

[0153] Furthermore, an upper space 131 and a lower space 132 are formed between the motor chamber 12 and the accommodation chamber 130 of the gear chamber 13 , and lubricating oil R3 is stored in both of them.

[0154] Thus, the upper space 131 and the lower space 132 can be provided while suppressing the increase in the upper and lower dimensions of the drive unit housing 11. Furthermore, by storing the lubricating oil R3 in the upper space 131 and the lower space 132, the height of the liquid level of the lubricating oil R3 stored in the lower part of the storage chamber 130 can be lowered, so that the stirring resistance of the lubricating oil R3 generated by the rotation of the reduction gear 30 can be further reduced.

[0155] On the other hand, the motor cooling oil R2 does not flow into the upper space 131 and the lower space 132 .

[0156] Thus, the lubricating oil R3 and the motor cooling oil R2 are not mixed, so that the contamination levels of the lubricating oil R3 and the motor cooling oil R2 can be separated, thereby preventing the lubricating oil R3 that easily contains a lot of sludge from being supplied to the drive motor 20 .

[0157] The motor chamber 12 has a substantially circular cross section as viewed from the output rotation axis direction of the drive motor 20. The accommodating chamber 130 has a substantially circular cross section as viewed from the output rotation axis direction of the speed reducer 30.

[0158] Moreover, when viewed from the direction of the rotation axes of the driving motor 20, the planetary gear mechanism 31 and the differential gear mechanism 32, that is, the left-right direction, the upper space 131 is formed in the upper area of ​​the rotation axis of the driving motor 20 and the rotation axes of the planetary gear mechanism 31 and the differential gear mechanism 32 between the motor chamber 12 and the receiving chamber 130, and the lower space 132 is formed in the lower area of ​​the rotation axis of the driving motor 20 and the rotation axes of the planetary gear mechanism 31 and the differential gear mechanism 32 between the motor chamber 12 and the receiving chamber 130.

[0159] Thus, the space in the upper and lower areas of the output rotating shaft of the drive motor 20 and the output rotating shaft of the reduction gear 30 located between the motor chamber 12 and the accommodation chamber 130 when viewed from the direction of the output rotating shaft of the drive motor 20 and the reduction gear 30, that is, the left-right direction, can be effectively utilized, thereby providing an upper space 131 and a lower space 132 as a storage portion for storing the lubricating oil R3 while suppressing an increase in the upper and lower dimensions of the drive unit housing 11.

[0160] When viewed from the direction of an imaginary straight line VL1 (front-to-back direction in this embodiment) perpendicular to the output rotating shaft of the driving motor 20 and the output rotating shaft of the reduction device 30 , the upper space 131 and the lower space 132 are both formed so as to at least partially overlap with the motor chamber 12 and the accommodating chamber 130 .

[0161] Thus, the projected area of ​​the drive unit case 11 when viewed from the direction of the virtual straight line VL1 (in the present embodiment, the front-rear direction) can be reduced, so that the drive unit case 11 can be miniaturized.

[0162] In particular, in the present embodiment, the upper space 131 and the lower space 132 are formed so that more than half of their projection areas when viewed in the direction of the virtual line VL1 (in the present embodiment, the front-rear direction) overlap with the motor chamber 12 and the accommodating chamber 130 .

[0163] This makes it possible to further reduce the projected area of ​​the drive unit case 11 when viewed from the direction of the virtual straight line VL1 (in the present embodiment, the front-rear direction), and thus further reduce the size of the drive unit case 11.

[0164] The upper space 131 extends in the axial direction of the output rotating shaft of the reduction gear 30 , and is divided into a planetary-side upper reservoir 131 a and a differential-side upper reservoir 131 b in the axial direction of the output rotating shaft of the reduction gear 30 .

[0165] The lower space 132 extends in the axial direction of the output rotating shaft of the reduction gear 30 , and is divided into a differential-side lower reservoir chamber 132 a and a planetary-side lower reservoir chamber 132 b in the axial direction of the output rotating shaft of the reduction gear 30 .

[0166] In this way, by forming the upper space 131 and the lower space 132 to be longer in the axial direction of the output rotating shaft of the reduction gear 30 and dividing the upper space 131 into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear 30, it is possible to extend the time for the lubricating oil R3 to stay in the upper space 131. As a result, the foam in the foaming lubricating oil R3 can be eliminated, and the lubricating oil R3 can be cooled.

[0167] Furthermore, the upper space 131 , that is, the planetary-side upper reservoir 131 a and the differential-side upper reservoir 131 b are integrally formed with the drive unit case 11 (the left main case 114 in the present embodiment) by casting.

[0168] Similarly, the lower space 132 , that is, the differential-side lower reservoir chamber 132 a and the planetary-side lower reservoir chamber 132 b are integrally formed with the drive unit case 11 (the left main case 114 in the present embodiment) by casting.

[0169] Thus, the upper space 131 and the lower space 132, more specifically, the planetary side upper storage portion 131a, the differential side upper storage portion 131b, the differential side lower storage chamber 132a, and the planetary side lower storage chamber 132b can be formed at low cost.

[0170] The planet-side upper storage portion 131a is provided at a position which is above the rotation axis of the input shaft 311 and below the upper end of the planetary gear mechanism 31 in the up-down direction, and at least partially overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311. The position which at least partially overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311 refers to a position which at least partially overlaps with the planetary gear mechanism 31 in the axial direction of the input shaft 311 when viewed from a predetermined direction in the radial direction outside the input shaft 311 toward the center of the input shaft 311.

[0171] A part of the lubricating oil R3 that is brought up and scattered from the lower part of the accommodation chamber 130 by the planetary gear mechanism 31 is collected and stored in the planetary-side upper storage portion 131 a .

[0172] Furthermore, a part of the lubricating oil R3 that is discharged and scattered radially outward from the oil supply hole 311 b of the input shaft 311 is collected and stored in the planetary-side upper reservoir 131 a .

[0173] Thus, the lubricating oil R3 discharged and scattered from the oil supply hole 311b of the input shaft 311 toward the radial outside and the lubricating oil R3 scattered by the planetary gear mechanism 31 are collected by the planetary upper storage portion 131a, so that the height of the liquid level of the lubricating oil R3 stored in the lower part of the storage chamber 130 can be further reduced, thereby further reducing the stirring resistance of the lubricating oil R3 generated with the rotation of the reduction gear 30. In this way, the height dimension of the drive unit 10 can be suppressed without reducing the power transmission efficiency.

[0174] The differential-side upper reservoir 131 b is provided at a position which is above the rotation axis of the differential case 321 and below the upper end of the differential case 321 in the up-down direction, and at least partially overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321. The position which at least partially overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321 refers to a position which at least partially overlaps with the differential gear mechanism 32 in the rotation axis direction of the differential case 321 when viewed from a predetermined direction in the radial direction outside the differential case 321 toward the rotation axis center of the differential case 321.

[0175] A part of the lubricating oil R3 scattered by being dragged up 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 in the differential side upper reservoir 131 b.

[0176] Furthermore, a part of the lubricating oil R3 that is discharged from the right end of the input shaft 311 toward the differential gear mechanism 32 and that is scattered by the rotation of the differential gear mechanism 32 is collected and stored in the differential-side upper reservoir 131 b .

[0177] Thus, 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, as well as the lubricating oil R3 scattered by being carried up from the lower part of the containing chamber 130 by the differential gear mechanism 32 including the differential case 321, are collected by the upper storage portion 131b on the differential side, thereby further reducing the height of the liquid level of the lubricating oil R3 stored in the lower part of the containing chamber 130, thereby further reducing the stirring resistance of the lubricating oil R3 generated by the rotation of the reduction device 30.

[0178] In the left main case 114, the planetary side upper reservoir 131a and the differential side upper reservoir 131b are adjacent to each other in the rotation axis direction of the planetary gear mechanism 31 and the differential gear mechanism 32 via the upper partition wall 114d. The upper partition wall 114d is provided with a first oil flow hole 134a that communicates the planetary side upper reservoir 131a and the differential side upper reservoir 131b and through which the lubricating oil R3 flows.

[0179] Thus, the lubricating oil R3 stored in the planetary-side upper reservoir 131 a can flow to the differential-side upper reservoir 131 b.

[0180] Furthermore, the height of the bottom surface 131 a 1 of the planetary-side upper reservoir 131 a is higher than the height of the bottom surface 131 b 1 of the differential-side upper reservoir 131 b .

[0181] This allows the lubricating oil R3 stored in the planetary-side upper reservoir 131 a to easily flow to the differential-side upper reservoir 131 b .

[0182] In addition, in the left main housing 114, a first ventilation hole 135a is provided at a position above the first oil circulation hole 134a of the upper dividing wall 114d, which 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.

[0183] In this way, it is possible to prevent the pressure in the planetary side upper storage section 131a and the differential side upper storage section 131b from increasing due to the gas in the planetary side upper storage section 131a and the differential side upper storage section 131b, thereby preventing the lubricating oil R3 stored in the planetary side upper storage section 131a from having difficulty flowing to the differential side upper storage section 131b.

[0184] The differential side lower storage chamber 132a is provided below the differential side upper storage section 131b. In the left main housing 114, the differential side upper storage section 131b and the differential side lower storage chamber 132a are adjacent in the vertical direction via the upper and lower dividing wall 114c described above. That is, the upper and lower dividing wall 114c forms the bottom wall of the differential side upper storage section 131b and the upper wall of the differential side lower storage chamber 132a. Moreover, the upper and lower dividing wall 114c is provided with a second oil flow hole 134b that connects the differential side upper storage section 131b and the differential side lower storage chamber 132a and allows the lubricating oil R3 to flow.

[0185] As described above, in the lower part of the gear chamber 13, the lower space 132 is divided into a chamber different from the containing chamber 130, so the lower storage chamber 132a on the differential side also becomes a chamber different from the containing chamber 130. Therefore, the lubricating oil R3 flowing from the planetary side upper storage part 131a to the differential side upper storage part 131b and stored in the differential side upper storage part 131b does not flow to the containing chamber 130, but flows to the differential side lower storage chamber 132a which is a chamber different from the containing chamber 130 through the second oil circulation hole 134b.

[0186] As a result, the height of the liquid level of the lubricating oil R3 stored in the storage chamber 130 can be maintained at a lower level, so that the stirring resistance of the lubricating oil R3 can be further reduced when the reduction gear device 30 rotates.

[0187] like Fig.19 As shown, the left main housing 114 and the right main housing 115 are assembled by sandwiching a gasket 136. The gasket 136 is a plate-shaped member extending in the up-down direction and the front-rear direction. Moreover, the upper storage portion 131b on the differential side is formed on the left side of the gasket 136, and the wall portion of the upper storage portion 131b on the differential side is formed by the left main housing 114 and the gasket 136. Moreover, the gasket 136 forms at least a part of the right wall of the upper storage portion 131b on the differential side. On the right side of the gasket 136, an air permeable chamber 137 is formed in a manner adjacent to the upper storage portion 131b on the differential side via the gasket 136, and the wall portion of the air permeable chamber 137 is formed by the right main housing 115 and the gasket 136. Moreover, the gasket 136 forms at least a part of the left wall of the air permeable chamber 137.

[0188] Thus, the wall portion of the differential-side upper reservoir 131 b and the air permeable chamber 137 can be formed at low cost while suppressing an increase in weight.

[0189] The gasket 136 is provided with an oil flow hole 136a which communicates the differential side upper reservoir 131b with the air permeable chamber 137 and allows the remaining lubricating oil R3 of the lubricating oil R3 stored in the differential side upper reservoir 131b which does not flow to the second oil flow hole 134b to pass through. In addition, a communication hole 136b which communicates the differential side upper reservoir 131b with the air permeable chamber 137 and allows the gas in the differential side upper reservoir 131b and the air permeable chamber 137 and the mist of the lubricating oil R3 to flow is provided above the oil flow hole 136a of the gasket 136.

[0190] Thus, the oil flow hole 136 a and the communication hole 136 b which communicate with the differential-side upper reservoir 131 b and the air breather chamber 137 can be easily formed.

[0191] like Fig. 20As shown, a vent hole 137a communicating with the outside of the drive unit housing 11 is provided at the upper portion of the vent chamber 137. When the pressure in the gear chamber 13 exceeds a predetermined pressure, gas is released from the vent hole 137a to maintain the pressure in the gear chamber 13 below the predetermined pressure.

[0192] In addition, in the flow direction of the lubricating oil R3 in the drive unit housing 11, an air permeable chamber 137 and an air permeable hole 137a are provided after passing through the planetary side upper storage portion 131a and the differential side upper storage portion 131b storing the lubricating oil R3. Thus, the air permeable chamber 137 and the air permeable hole 137a can be formed in the deep part of the drive unit housing 11, so that it is possible to suppress external contaminants such as dirt and water from mixing into the lubricating oil R3. In addition, the air permeable chamber 137 and the air permeable hole 137a can be formed at a position away from heat sources such as the drive motor 20 and the reduction gear 30, so it is also possible to prevent the lubricating oil R3 from thermally expanding and spraying out to the outside of the drive unit housing 11.

[0193] like Fig. 20 and Fig.21 As shown, the drive unit housing 11 (the right main housing 115 in this embodiment) is provided with a right drive shaft bearing 115b for axially supporting the right drive shaft 325R.

[0194] The bottom of the air breather chamber 137 is provided with an air discharge hole 137b for discharging the lubricating oil R3 that enters the air breather chamber 137 from the upper storage portion 131b on the differential side through the oil flow hole 136a and the lubricating oil R3 that enters the air breather chamber 137 from the upper storage portion 131b on the differential side through the communication hole 136b, condenses into liquid in the air breather chamber 137 and is stored in the lower part of the air breather chamber 137 from the air breather chamber 137. The air discharge hole 137b communicates the air breather chamber 137 with the accommodation chamber 130, and an oil guide portion 115c is formed in the drive unit housing 11 (in this embodiment, the right main housing 115) for guiding the lubricating oil R3 that flows out of the air discharge hole 137b to the accommodation chamber 130 to the right drive shaft bearing 115b.

[0195] Thus, the lubricating oil R3 condensed into liquid in the air chamber 137 and stored in the lower part of the air chamber 137 can be discharged from the air discharge hole 137b, and the right drive shaft bearing 115b is lubricated by the lubricating oil R3 discharged from the air discharge hole 137b. Therefore, the lubricating oil R3 stored in the lower part of the air chamber 137 can be utilized to efficiently lubricate the right drive shaft bearing 115b.

[0196] Furthermore, the lubricating oil R3 that is condensed into liquid in the air permeable chamber 137 and stored in the lower portion of the air permeable chamber 137 can be discharged from the air permeable chamber 137 and returned to the storage chamber 130 .

[0197] In the present embodiment, the oil guide portion 115 c has a groove shape extending from the right main housing 115 , is integrally formed with the right main housing 115 by casting, and an opening surface of the oil guide portion 115 c is covered by a plate-like side member.

[0198] Thus, the oil guide portion 115c can be formed at low cost.

[0199] return Figures 15 to 19 , the planetary side lower storage chamber 132b is arranged adjacent to the left side of the differential side lower storage chamber 132a. In the left main housing 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 via the lower partition wall 114e. 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. In addition, the lower partition wall 114e is provided with a third oil flow hole 134c which connects the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b and allows the lubricating oil R3 to flow.

[0200] As described above, at the lower part of the gear chamber 13, the lower space 132 is divided into a chamber different from the containing chamber 130, and therefore, the planetary side lower storage chamber 132b also becomes a chamber different from the containing chamber 130. Therefore, the lubricating oil R3 flowing into the differential side lower storage chamber 132a does not flow to the containing chamber 130, but flows to the planetary side lower storage chamber 132b which is a chamber different from the containing chamber 130 through the third oil flow hole 134c.

[0201] As a result, the height of the liquid level of the lubricating oil R3 stored in the storage chamber 130 can be maintained at a lower level, so that the stirring resistance of the lubricating oil R3 can be further reduced when the reduction gear device 30 rotates.

[0202] In addition, since the lubricating oil R3 flows from the differential side lower storage chamber 132a to the planet side lower storage chamber 132b through the third oil flow hole 134c, the movement speed of the lubricating oil R3 from the differential side lower storage chamber 132a to the planet side lower storage chamber 132b can be reduced by setting the diameter of the third oil flow hole 134c to be small. As a result, the movement time of the lubricating oil R3 from the differential side lower storage chamber 132a to the planet side lower storage chamber 132b can be extended, more bubbles in the lubricating oil R3 can be eliminated, and the temperature of the lubricating oil R3 can be reduced.

[0203] In addition, in the left main housing 114, a second vent hole 135b is provided at a position above the third oil circulation hole 134c of the lower dividing wall 114e, which connects the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b and allows the gas in the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b to circulate.

[0204] In this way, it is possible to prevent the pressure in the differential side lower storage chamber 132a and the planetary side lower storage chamber 132b from increasing due to the gas in 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 having difficulty flowing to the planetary side lower storage chamber 132b.

[0205] Furthermore, the height of the bottom surface 132a1 of the differential-side lower storage chamber 132a is higher than the height of the bottom surface 132b1 of the planetary-side lower storage chamber 132b.

[0206] This allows the lubricating oil R3 stored in the differential-side lower reservoir chamber 132a to easily flow into the planetary-side lower reservoir chamber 132b.

[0207] At least a part 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 divided by the baffle plate 116.

[0208] Thus, the planetary side lower storage chamber 132b can be formed at low cost while suppressing an increase in weight.

[0209] The baffle plate 116 is provided with an oil discharge hole 116 b which connects the planetary lower storage chamber 132 b and the chain chamber 14 and through which the lubricating oil R3 flows.

[0210] Therefore, 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 receiving chamber 130 after lubricating and cooling the reduction gear 30, is carried up by the rotation of the reduction gear 30, a part of which is collected by the upper storage portion 131a on the planetary side and the upper storage portion 131b on the differential side, and returns to the chain chamber 14 from the oil discharge hole 116b after flowing through the upper storage portion 131b on the differential side, the lower storage chamber 132a on the differential side, and the lower storage chamber 132b on the planetary side.

[0211] In this way, the oil discharge hole 116 b for discharging the lubricating oil R3 circulated in the gear chamber 13 from the gear chamber 13 can be easily formed.

[0212] Above, one embodiment of the present invention has been described with reference to the accompanying drawings, but the present invention is certainly not limited to this embodiment. Obviously, those skilled in the art can think of various variations or modifications within the scope of the technical solution, and it should be understood that these variations and modifications also belong to the technical scope of the present invention. In addition, the various constituent elements in the above-mentioned embodiment can also be arbitrarily combined within the scope of the main purpose of the invention.

[0213] At least the following matters are described in this specification: In parentheses, corresponding components in the above-mentioned embodiment are shown as an example, but the present invention is not limited to this.

[0214] (1) A drive unit (drive unit 10), comprising:

[0215] a driving motor (driving motor 20);

[0216] a speed reduction device (speed reduction device 30) for reducing the speed of output power of the driving motor; and

[0217] a drive unit housing (drive unit housing 11) that accommodates the drive motor and the reduction gear,

[0218] in,

[0219] The output rotating shaft of the driving motor and the output rotating shaft of the reduction gear are parallel to each other and arranged in a horizontal direction.

[0220] The drive unit housing has:

[0221] a motor chamber (motor chamber 12) which accommodates the driving motor; and

[0222] The gear chamber (gear chamber 13) is provided with a receiving chamber (receiving chamber 130) for receiving the reduction gear.

[0223] The motor chamber and the gear chamber are divided by a partition wall (second partition wall 114b).

[0224] An upper space (upper space 131) and a lower space (lower space 132) separated up and down by upper and lower partition walls (upper and lower partition walls 114c) extending from the partition wall are formed between the motor room and the storage room.

[0225] According to (1), the upper space and the lower space can be provided in the drive unit case while suppressing an increase in the vertical dimension of the drive unit case.

[0226] (2) The drive unit according to (1), wherein:

[0227] The motor chamber has a substantially circular cross-section when viewed from the output rotation axis direction of the drive motor.

[0228] The accommodating chamber has a substantially circular cross-section when viewed from the output rotation axis direction of the reduction gear transmission.

[0229] According to (2), the space in the upper and lower areas of the output rotating shaft of the driving motor and the output rotating shaft of the reduction gear located between the motor chamber and the accommodation chamber as viewed from the direction of the output rotating shaft of the driving motor and the reduction gear can be effectively utilized, thereby providing the upper and lower spaces while suppressing the increase in the upper and lower dimensions of the driving unit housing.

[0230] (3) The drive unit according to (1), wherein:

[0231] When viewed from a virtual straight line (virtual straight line VL1) perpendicular to the output rotating shaft of the drive motor and the output rotating shaft of the reduction gear, the upper space and the lower space are formed so as to at least partially overlap with the motor chamber and the accommodating chamber.

[0232] According to (3), the projected area of ​​the drive unit case when viewed from the imaginary straight line direction can be reduced, so the drive unit case can be miniaturized.

[0233] (4) The drive unit according to (1), wherein:

[0234] When viewed from an imaginary straight line (imaginary straight line VL1) orthogonal to the output rotating shaft of the driving motor and the output rotating shaft of the reduction device, the upper space and the lower space are formed so that more than half of the projected area when viewed from the imaginary straight line overlaps with the motor room and the storage room.

[0235] According to (4), the projected area of ​​the drive unit case when viewed from the imaginary straight line direction can be further reduced, so the drive unit case can be further miniaturized.

[0236] (5) The drive unit according to (1), wherein:

[0237] The upper space and the lower space store lubricating fluid (lubricating oil R3) for lubricating the reduction gear.

[0238] According to (5), by storing the lubricating fluid in the upper space and the lower space, the liquid level of the lubricating fluid stored in the lower portion of the storage chamber can be lowered, thereby further reducing the stirring resistance of the lubricating fluid generated by the rotation of the reduction gear.

[0239] (6) The drive unit according to (5), wherein:

[0240] The motor coolant (motor cooling oil R2) for cooling the driving motor does not flow into the upper space and the lower space.

[0241] According to (6), the lubricating fluid for lubricating the reduction gear device and the motor coolant for cooling the drive motor are not mixed, so that the contamination levels in the lubricating fluid and the motor coolant can be separated, thereby preventing the lubricating fluid that easily contains a large amount of sludge from being supplied to the drive motor.

[0242] (7) The drive unit according to (1), wherein:

[0243] The upper space and the lower space are integrally formed with the driving unit housing by casting.

[0244] According to (7), the upper space and the lower space can be formed at low cost.

[0245] (8) The drive unit according to (5), wherein:

[0246] The upper space and the lower space extend in the axial direction of the output rotating shaft of the reduction gear transmission.

[0247] According to (8), by forming the upper space and the lower space to be longer in the axial direction of the output rotating shaft of the reduction gear, the time during which the lubricating fluid stored in the upper space and the lower space stays in the upper space and the lower space can be prolonged. Thus, the bubbling of the lubricating fluid can be suppressed and the temperature of the lubricating fluid can be reduced.

[0248] (9) The drive unit according to (8), wherein:

[0249] The upper space and the lower space are divided into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear transmission.

[0250] According to (9), by dividing the upper space and the lower space into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear, the time during which the lubricating fluid stored in the upper space and the lower space stays in the upper space and the lower space can be further prolonged. Thus, the bubbling of the lubricating fluid can be further suppressed, and the temperature of the lubricating fluid can be further reduced.

[0251] (10) The drive unit according to (1), wherein:

[0252] The reduction gear device includes a planetary gear mechanism (planetary gear mechanism 31 ).

[0253] According to (10), since the reduction gear device has a planetary gear mechanism, it is possible to suppress an increase in the radial dimension of the reduction gear device relative to the rotation axis direction and obtain a desired reduction ratio.

[0254] (11) The drive unit according to (10), wherein:

[0255] The speed reduction device has a differential gear mechanism (differential gear mechanism 32).

[0256] An input rotation shaft of the planetary gear mechanism is coaxial with an output rotation shaft of the differential gear mechanism.

[0257] 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 device can be further miniaturized.

[0258] (12) The drive unit according to (11), wherein:

[0259] 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).

[0260] The power input to the planetary gear mechanism is output from the planet carrier.

[0261] The planetary carrier is formed integrally with a differential case (differential case 321 ) of the differential gear mechanism.

[0262] According to (12), the planetary carrier and the differential case are formed integrally, so that the planetary gear mechanism and the differential gear mechanism can be constructed as an integral whole, and the reduction gear device can be further miniaturized.

Claims

1. A drive unit comprising: A driving motor; a reduction gear, which is used to reduce the speed of output power of the driving motor; and a drive unit housing that accommodates the drive motor and the reduction gear, in, The output rotating shaft of the driving motor and the output rotating shaft of the reduction gear are parallel to each other and arranged in a horizontal direction. The drive unit housing has: a motor chamber that accommodates the driving motor; and The gear chamber is provided with a receiving chamber for receiving the reduction gear. The motor chamber and the gear chamber are divided by a partition wall. An upper space and a lower space separated vertically by upper and lower partition walls extending from the partition wall are formed between the motor room and the storage room.

2. The drive unit according to claim 1, wherein: The motor chamber has a substantially circular cross-section when viewed from the output rotation axis direction of the drive motor. The accommodating chamber has a substantially circular cross-section when viewed from the output rotation axis direction of the reduction gear transmission.

3. The drive unit according to claim 1, wherein: The upper space and the lower space are formed so as to at least partially overlap with the motor chamber and the accommodating chamber when viewed from a virtual straight line perpendicular to the output rotating shaft of the driving motor and the output rotating shaft of the reduction gear.

4. The drive unit according to claim 1, wherein: When viewed from an imaginary straight line orthogonal to the output rotating shaft of the drive motor and the output rotating shaft of the reduction gear, the upper space and the lower space are formed so that more than half of the projected area when viewed from the imaginary straight line overlaps with the motor room and the accommodating room.

5. The drive unit according to claim 1, wherein: The upper space and the lower space store lubricating fluid for lubricating the reduction gear.

6. The drive unit according to claim 5, wherein: Motor coolant for cooling the driving motor does not flow into the upper space and the lower space.

7. The drive unit according to claim 1, wherein: The upper space and the lower space are integrally formed with the driving unit housing by casting.

8. The drive unit according to claim 5, wherein: The upper space and the lower space extend in the axial direction of the output rotating shaft of the reduction gear transmission.

9. The drive unit according to claim 8, wherein: The upper space and the lower space are divided into a plurality of spaces in the axial direction of the output rotating shaft of the reduction gear transmission.

10. The drive unit according to claim 1, wherein: The reduction gear device has a planetary gear mechanism.

11. The drive unit according to claim 10, wherein: The reduction gear has a differential gear mechanism. An input rotation shaft of the planetary gear mechanism is coaxial with an output rotation shaft of the differential gear mechanism.

12. The drive unit according to claim 11, wherein: 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 planet carrier. The planet carrier is formed integrally with a differential case of the differential gear mechanism.

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