CN111989234A

CN111989234A - Motor unit

Info

Publication number: CN111989234A
Application number: CN201980025763.2A
Authority: CN
Inventors: 山口康夫; 藤原久嗣; 中村圭吾; 桧皮隆宏
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2018-04-20
Filing date: 2019-03-28
Publication date: 2020-11-24
Anticipated expiration: 2039-03-28
Also published as: WO2019202947A1; CN111989234B

Abstract

A motor unit according to an aspect of the present invention is a motor unit for rotating an axle of a vehicle, the motor unit including: a motor having a motor shaft that rotates about a motor axis; a reduction gear connected to the motor shaft; a differential device connected to the reduction gear device and configured to rotate the axle about a differential axis; a housing having a motor housing portion that houses a motor and a gear housing portion that houses a reduction gear and a differential gear and houses oil therein; and a reservoir portion that is opened vertically upward inside the gear housing portion and that can store oil. The differential axis coincides with the motor axis. The motor shaft is a hollow shaft that is open on both sides in the axial direction. An axle is inserted into the motor shaft. One end of the motor shaft in the axial direction protrudes into the gear housing. At least a part of a radial gap between the motor shaft and the axle in the opening on one side in the axial direction of the motor shaft is located inside the reservoir.

Description

Motor unit

Technical Field

The present invention relates to a motor unit.

Background

Electric drives for driving a vehicle are known. For example, patent document 1 describes a structure in which an output shaft penetrates a hollow shaft of a motor.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open gazette: japanese patent laid-open publication No. 2017-534032

Disclosure of Invention

Problems to be solved by the invention

In the above-described structure, it is considered to supply oil to the inside of the hollow shaft to cool the motor. However, since the output shaft is inserted into the hollow shaft, it is necessary to supply oil to a gap between the hollow shaft and the output shaft, and it is difficult to supply oil to the inside of the hollow shaft. Therefore, it is difficult to sufficiently secure the supply amount of the oil to the motor.

In view of the above circumstances, an object of the present invention is to provide a motor unit having a structure capable of increasing the supply amount of oil into a hollow motor shaft through which a vehicle shaft passes.

Means for solving the problems

A motor unit according to an aspect of the present invention is a motor unit for rotating an axle of a vehicle, the motor unit including: a motor having a motor shaft that rotates about a motor axis; a reduction gear connected to the motor shaft; a differential device connected to the reduction gear device and configured to rotate the axle about a differential axis; a housing having a motor housing portion that houses the motor and a gear housing portion that houses the reduction gear and the differential gear and houses oil therein; and a reservoir portion that is opened vertically upward inside the gear housing portion and that is capable of storing oil. The differential axis is coincident with the motor axis. The motor shaft is a hollow shaft that is open on both sides in the axial direction. The axle is inserted into the motor shaft. An end portion of the motor shaft on one axial side protrudes into the gear housing portion. At least a part of a radial gap between the motor shaft and the axle in the opening on one axial side of the motor shaft is located inside the reservoir.

Effects of the invention

According to one aspect of the present invention, in the motor unit, the supply amount of oil into the hollow motor shaft through which the vehicle shaft passes can be increased.

Drawings

Fig. 1 is a diagram schematically showing a power train having a motor unit of the present embodiment.

Fig. 2 is a diagram schematically showing a power train having the motor unit of the present embodiment.

Fig. 3 is a diagram schematically showing a power train having the motor unit of the present embodiment.

Fig. 4 is a perspective view showing the motor unit of the present embodiment.

Fig. 5 is a right side view of the motor unit of the present embodiment.

Fig. 6 is a view of a part of the motor unit of the present embodiment as viewed from above.

Fig. 7 is a sectional view showing a part of the motor unit of the present embodiment, and is a sectional view taken along line VII-VII of fig. 6.

Fig. 8 is a sectional view showing a part of the motor unit of the present embodiment, and is a sectional view taken along line VIII-VIII of fig. 7.

Detailed Description

In the following description, the vertical direction is defined based on the positional relationship in the case where the motor unit 10 of the present embodiment shown in the drawings is mounted on a vehicle on a horizontal road surface, and the description is given. In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The + Z side is the upper side in the vertical direction, and the-Z side is the lower side in the vertical direction. In the following description, the vertical upper side is simply referred to as "upper side", and the vertical lower side is simply referred to as "lower side". The X-axis direction is a direction perpendicular to the Z-axis direction, and is a front-rear direction of the vehicle on which the motor unit 10 is mounted. In the present embodiment, the + X side is the front side of the vehicle and the-X side is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is a left-right direction of the vehicle (vehicle width direction). In the present embodiment, the + Y side is the left side of the vehicle and the-Y side is the right side of the vehicle. In the present embodiment, the right side corresponds to one axial side.

The positional relationship in the front-rear direction is not limited to that of the present embodiment, and the + X side may be the rear side of the vehicle and the-X side may be the front side of the vehicle. In this case, the + Y side is the right side of the vehicle and the-Y side is the left side of the vehicle.

The motor axis J1 shown in the drawings as appropriate extends in the Y-axis direction, i.e., the left-right direction of the vehicle. In the following description, unless otherwise specified, a direction parallel to the motor axis J1 is simply referred to as an "axial direction", a radial direction about the motor axis J1 is simply referred to as a "radial direction", and a circumferential direction about the motor axis J1, that is, a direction around the motor axis J1 is simply referred to as a "circumferential direction". In the present specification, the "parallel direction" also includes a substantially parallel direction, and the "perpendicular direction" also includes a substantially perpendicular direction.

As shown in fig. 1 to 3, the motor unit 10 of the present embodiment is provided in the power train 1. The power train 1 has a motor unit 10, an engine 2, and a battery 3. The power train 1 is mounted on a vehicle such as a Hybrid Electric Vehicle (HEV) or a plug-in hybrid electric vehicle (PHV) that uses a motor unit 10 and an engine 2 as power sources.

The engine 2 is an internal combustion engine that burns fuel such as gasoline and light oil. The engine 2 is, for example, a gasoline engine or a diesel engine. The engine 2 of the present embodiment is a so-called transverse engine in which the orientation of the crankshaft 2a coincides with the lateral direction, i.e., the axial direction, of the vehicle. The battery 3 supplies electric power to the motor unit 10.

The motor unit 10 of the present embodiment is mounted on a vehicle having an engine 2, and rotates an axle AX of the vehicle. The motor unit 10 includes a housing 11, a motor 20, a reduction gear 30, a differential gear 50, a generator 40, and a clutch mechanism 60, wherein the motor 20 has a motor shaft 22 that rotates about a motor axis J1.

The housing 11 houses the motor 20, the reduction gear unit 30, the differential unit 50, the generator 40, and the clutch mechanism 60. As shown in fig. 4 to 6, the housing 11 has a motor housing 12 and a gear housing 13. The motor housing portion 12 is a portion that houses the motor 20. The motor housing portion 12 has a cylindrical shape extending in the axial direction about the motor axis J1. The gear housing 13 is a portion that houses the reduction gear unit 30, the generator 40, and the differential unit 50. The gear housing 13 is located on the right side of the motor housing 12. The gear housing 13 projects forward of the motor housing 12.

As shown in fig. 7, oil O is contained inside the housing 11. More specifically, the oil O is contained in each of the motor containing section 12 and the gear containing section 13. An oil reservoir OR1 in which the oil supply O is stored is provided in a region below the motor housing portion 12. An oil reservoir OR2 in which the oil supply O is stored is provided in a region below the gear housing 13. In fig. 7, the oil level of the oil reservoir OR1 in the motor housing 12 is located, for example, above the oil level of the oil reservoir OR2 in the gear housing 13. The oil level of the oil reservoir OR1 is located below the rotor 21, for example, when the motor 20 is driven. This can prevent the rotation of the rotor 21 from being hindered by the oil O in the oil reservoir OR 1. In fig. 7, the engine axis J2, the generator 40, and the clutch mechanism 60 are not shown.

The housing 11 also has a partition wall portion 14 and a bearing holding wall portion 15. The partition wall 14 partitions the motor housing portion 12 and the gear housing portion 13. The partition wall 14 has a hole 14a that penetrates the partition wall 14 in the axial direction. The hole 14a is filled with an axle AX and a motor shaft 22. The motor shaft 22 is supported so as to be rotatable, and the bearing 27b is fitted into and held by the hole 14 a.

The partition wall 14 has an oil passage 14b connecting the inside of the motor housing 12 and the inside of the gear housing 13. The oil passage 14b penetrates the partition wall 14 in the axial direction. In the present embodiment, the oil passage 14b extends linearly in the axial direction. The oil passage 14b is located below the hole 14 a. The oil O in the motor housing 12 can move into the gear housing 13 through the oil passage 14 b.

The bearing holding wall 15 extends radially inward from the inner circumferential surface of the motor housing 12. The bearing holding wall 15 is located on the left side of a stator 24 described later. The interior of the motor housing portion 12 is partitioned by a bearing holding wall portion 15 in the axial direction. The bearing holding wall 15 has a hole 15a that penetrates the bearing holding wall 15 in the axial direction. The hole 15a is filled with an axle AX and a motor shaft 22. The motor shaft 22 is supported so as to be rotatable, and the bearing 27a is fitted into and held by the hole 15 a. The bearing holding wall 15 has a through portion 15b at a lower end portion. The through portion 15b connects portions of the interior of the motor housing portion 12 that are separated in the axial direction by the bearing holding wall portion 15. Since the through portion 15b is provided, the oil reservoir OR1 is provided across portions on both sides in the axial direction of the bearing holding wall 15 in the interior of the motor housing portion 12.

The motor 20 outputs torque that rotates the axle AX. The torque of the motor 20 is transmitted to the axle AX via the reduction gear 30 and the differential device 50. In the present embodiment, the motor 20 also functions as a generator. The motor 20 functions as a generator during regeneration, for example.

The motor 20 has a rotor 21 and a stator 24. The rotor 21 has a motor shaft 22 and a rotor main body 23. The rotor body 23 is fixed to the outer peripheral surface of the motor shaft 22. Although not shown, the rotor body 23 includes a rotor core and a rotor magnet.

The motor shaft 22 extends in the axial direction about a motor axis J1. The motor shaft 22 is a hollow shaft that is open on both sides in the axial direction. As shown in fig. 8, the outer shape of the motor shaft 22 as viewed in the axial direction is a circle centered on the motor axis J1. As shown in fig. 7, the motor shaft 22 is supported by

bearings

27a and 27b to be rotatable about a motor axis J1. The

bearings

27a and 27b are ball bearings, for example. The bearing 27a is held by the bearing holding wall 15 and supports a portion of the motor shaft 22 on the left side of the rotor body 23. The bearing 27b is held by the partition wall 14 and supports a portion of the motor shaft 22 on the right side of the rotor body 23.

The right end of the motor shaft 22 protrudes into the gear housing 13 through the hole 14 a. A reduction gear 30 is connected to the right end of the motor shaft 22. The left end of the motor shaft 22 protrudes through the hole 15a to the left of the bearing holding wall 15 in the motor housing 12.

The motor shaft 22 has shaft through

holes

22a, 22b, 22c, and 22d connecting the inside of the motor shaft 22 and the outer peripheral surface of the motor shaft 22. In the present embodiment, a plurality of shaft through

holes

22a, 22b, 22c, and 22d are provided in the circumferential direction. The shaft through

holes

22a and 22b are provided in the motor shaft 22 at a portion between the partition wall 14 and the bearing holding wall 15 in the axial direction. The shaft through hole 22a is provided in a portion of the motor shaft 22 on the left side of the rotor body 23. The shaft through hole 22b is provided in a portion of the motor shaft 22 on the right side of the rotor body 23. The shaft through

holes

22a and 22b are opposed to a coil 26, which will be described later, with a gap therebetween in the radial direction.

The shaft through hole 22c is provided in a portion of the motor shaft 22 located in the hole portion 15 a. The shaft through hole 22c opens into the hole portion 15 a. The shaft through hole 22d is provided in a portion of the motor shaft 22 located in the hole portion 14 a. The shaft through hole 22d opens into the hole 14 a.

The stator 24 is radially opposed to the rotor 21 with a gap therebetween. The stator 24 is located radially outside the rotor 21. The stator 24 includes a stator core 25, an insulator not shown, and a plurality of coils 26. The plurality of coils 26 are attached to the stator core 25 via an insulator not shown. The stator 24 is fixed inside the motor housing 12. The lower end of the stator 24 is immersed in the oil reservoir OR 1.

The reduction device 30 reduces the rotation speed of the motor 20, and increases the torque output from the motor 20 according to the reduction ratio. The reduction gear device 30 transmits the torque output from the motor 20 to the differential device 50. The reduction gear 30 has a motor drive gear 31, a counter gear 32, a drive gear 33, and a counter shaft 34. The motor drive gear 31 is fixed to the motor shaft 22. Thereby, the reduction gear 30 is connected to the motor shaft 22. In the present embodiment, the motor drive gear 31 is fixed to the right end of the motor shaft 22.

The counter gear 32 rotates about a counter axis J3 parallel to the motor axis J1. The secondary axis J3 is located radially outward of the motor axis J1. In the present embodiment, the sub-axis J3 is located above the motor axis J1. As shown in fig. 5, the secondary axis J3 is located on the front side of the motor axis J1.

As shown in fig. 7, the counter gear 32 meshes with the motor drive gear 31. The counter gear 32 is located on the upper side of the motor drive gear 31. The drive gear 33 is located to the right of the counter gear 32. The drive gear 33 rotates about the secondary axis J3 together with the counter gear 32. The drive gear 33 has an outer diameter smaller than that of the counter gear 32.

The counter shaft 34 extends axially about a counter axis J3. The counter shaft 34 is supported by

bearings

35a, 35b to be rotatable about a counter axis J3. The

bearings

35a and 35b are, for example, ball bearings. The

bearings

35a and 35b are held by wall portions on both sides in the axial direction of the gear housing 13. The counter gear 32 and the drive gear 33 are fixed to the outer peripheral surface of the counter shaft 34. Therefore, the counter gear 32 and the drive gear 33 are coupled via the counter shaft 34.

The torque output from the motor shaft 22 of the motor 20 is transmitted to the differential device 50 via the motor drive gear 31, the counter gear 32, and the drive gear 33 in this order. The gear ratio of each gear, the number of gears, and the like can be variously changed according to a required reduction ratio. In the present embodiment, the reduction gear 30 is a parallel shaft gear type reduction gear in which the axes of the gears are arranged in parallel.

The differential device 50 is connected to the reduction gear device 30. The differential device 50 is a device for transmitting the torque output from the motor 20 to the wheels H of the vehicle. The differential device 50 transmits torque to the axle AX, thereby rotating the axle AX about the differential axis. The differential axis of the differential device 50 coincides with the motor axis J1. The axle AX is provided in a pair so as to sandwich the differential device 50 in the axial direction. The pair of axles AX extend in the axial direction. The axle AX has a cylindrical shape centered on the motor axis J1. The left axle AX of the pair of axles AX opens into the motor shaft 22, which is a hollow shaft. Therefore, the motor unit 10 can be easily reduced in size in the radial direction, as compared with the case where the motor axis J1 and the differential axis are not coaxially arranged. Therefore, according to the present embodiment, the motor unit 10 having the generator 40 connected to the engine 2 can be downsized. Of the pair of axles AX, the left axle AX axially penetrates the motor shaft 22.

In each of the pair of axles AX, an axial end portion of the axle AX opposite to the side connected to the differential device 50 protrudes in the axial direction from the housing 11. As shown in fig. 1 to 3, in each of the pair of axles AX, a wheel H is mounted respectively at axial end portions of the axle AX that protrude from the housing 11.

The differential device 50 includes a ring gear 51, a pair of pinion gears not shown, a pinion shaft not shown, and a pair of side gears not shown. In the present embodiment, the ring gear 51 is located on the right side of the motor shaft 22 and the motor drive gear 31. The ring gear 51 rotates about the differential axis (the motor axis J1). The ring gear 51 meshes with the drive gear 33. Thereby, the torque output from the motor 20 is transmitted to the ring gear 51 via the reduction gear 30. As shown in fig. 7, the lower end portion of the ring gear 51 is immersed in the oil reservoir OR2 in the gear housing 13. Thereby, the oil O is lifted by the rotation of the ring gear 51. The oil O lifted up is atomized and dispersed in the gear housing 13. This enables the oil O to be supplied to each part disposed inside the gear housing 13.

The generator 40 shown in fig. 1 to 3 generates electricity using the power of the engine 2. The electric power generated by the generator 40 is charged to the battery 3 that supplies electric power to the motor 20, or is supplied to the stator 24 of the motor 20 without passing through the battery 3. In this way, the generator 40 can supply electric power to the motor 20. In the present embodiment, the generator 40 also functions as a motor. The generator 40 functions as a motor (starter) when the engine 2 is started, for example.

As shown in fig. 6, in the present embodiment, the generator 40 is connected to the reduction gear unit 30 via the clutch mechanism 60. Thereby, the power of the engine 2 is transmitted to the differential device 50 via the generator 40, the clutch mechanism 60, and the reduction gear device 30. The generator 40 is located on the front side of the reduction gear unit 30 and the differential unit 50. As shown in fig. 1 to 3, the generator 40 has a rotor 41 and a stator 44. The rotor 41 includes an engine drive shaft 42 that rotates about an engine axis J2 parallel to the motor axis J1, and a rotor main body 43.

The engine axis J2 is located radially outward of the motor axis J1. As shown in fig. 5, in the present embodiment, the engine axis J2 is located on the front side of the motor axis J1 and the secondary axis J3. The motor axis J1 is located at substantially the same position as the engine axis J2 in the vertical direction. In the present embodiment, the engine axis J2 is located slightly above the motor axis J1. As shown in fig. 1 to 3, the rotor main body 43 is fixed to the outer peripheral surface of the engine drive shaft 42. Although not shown, the rotor body 43 has a rotor core and a rotor magnet.

The engine drive shaft 42 has a cylindrical shape extending in the axial direction about the engine axis J2. As shown in fig. 4, the right end of the engine drive shaft 42 protrudes outside the housing 11. As shown in fig. 1 to 3, the right end of the engine drive shaft 42 is connected to the engine 2 via a damper 2 b. Thereby, the motor unit 10 is connected to the engine 2. The damper 2b functions as a torque limiter. The damper 2b reduces vibration caused by rapid torque variation such as when the vehicle is rapidly accelerated by the engine 2. The engine drive shaft 42 is rotated about an engine axis J2 by the engine 2. That is, the rotor 41 is rotated by the power of the engine 2. As a result, a voltage is generated in the stator 44 by electromagnetic induction, and the generator 40 can generate electric power.

As described above, according to the present embodiment, the power of the engine 2 is transmitted to the engine drive shaft 42 of the generator 40 without passing through a gear. Therefore, the number of shafts and gears required for power transmission from the engine 2 to the axle AX can be reduced. Therefore, the motor unit 10 can be further downsized and lightened.

Although not shown, the engine drive shaft 42 has an oil passage extending in the axial direction inside. Although not shown, the engine drive shaft 42 has a shaft through hole that connects an oil passage provided inside and the outer peripheral surface of the engine drive shaft 42. The shaft through holes of the engine drive shaft 42 are provided in plural numbers, for example, similarly to the shaft through

holes

22a, 22b, 22c, and 22d of the motor shaft 22.

The stator 44 is opposed to the rotor 41 with a gap therebetween in the radial direction of the engine axis J2. The stator 44 is located outside the rotor 41 in the radial direction of the engine axis J2. The stator 24 includes a stator core 45, an insulator not shown, and a plurality of coils 46. The plurality of coils 46 are attached to the stator core 45 via an insulator not shown. The stator 44 is fixed inside the gear housing 13.

The clutch mechanism 60 switches the connection and disconnection of the generator 40 to and from the reduction gear 30. The clutch mechanism 60 of the present embodiment is referred to as a rotation synchronization device or a synchronization engagement mechanism, for example. The clutch mechanism 60 includes a clutch shaft 61, a first flange portion 62, a second flange portion 63, an engine drive gear 64, a movable portion 65, and a synchronizer ring, not shown. As shown in fig. 4 to 6, the clutch mechanism 60 includes a driving unit 66. The driving portion 66 is attached to an upper wall portion of the gear housing portion 13. The driving unit 66 is driven by being supplied with electric power from the battery 3, for example.

As shown in fig. 1 to 3, the clutch shaft 61 is located on the left side of the engine drive shaft 42 and extends in the axial direction about the engine axis J2. Although not shown, the clutch shaft 61 has an oil passage extending in the axial direction inside. When the clutch shaft 61 is coupled to the engine drive shaft 42, an oil passage inside the clutch shaft 61 is connected to an oil passage inside the engine drive shaft 42. Although not shown, the clutch shaft 61 has a shaft through hole that connects an oil passage provided inside and the outer peripheral surface of the clutch shaft 61. The plurality of shaft through holes of the clutch shaft 61 are provided similarly to the shaft through

holes

22a, 22b, 22c, and 22d of the motor shaft 22, for example.

The first flange portion 62 is expanded outward in the radial direction of the engine axis J2 from the left end portion of the engine drive shaft 42. The second flange portion 63 extends outward in the radial direction of the engine axis J2 from the right end of the clutch shaft 61. Although not shown, external spline teeth are provided on the outer peripheral surface of the first flange portion 62 and the outer peripheral surface of the second flange portion 63, respectively.

The engine drive gear 64 is fixed to the left end of the clutch shaft 61. The engine drive gear 64 rotates about the engine axis J2 together with the clutch shaft 61. With the clutch mechanism 60 connected to the generator 40, the engine drive gear 64 is rotated by the engine 2 via the generator 40. The engine drive gear 64 meshes with the counter gear 32. Thereby, the generator 40 is connected to the reduction gear 30.

The movable portion 65 is moved in the axial direction by the driving portion 66. Although not shown, the movable portion 65 has a cylindrical shape surrounding the engine axis J2. Although not shown, an internal spline is provided on the inner peripheral surface of the movable portion 65. The movable portion 65 surrounds the outside of the second flange portion 63 in the radial direction of the engine axis J2, so that the internal spline meshes with the external spline of the second flange portion 63. Thereby, the movable portion 65 rotates together with the clutch shaft 61, the second flange portion 63, and the engine drive gear 64.

The movable portion 65 is moved in the axial direction by the driving portion 66, thereby switching the connection and disconnection between the clutch mechanism 60 and the generator 40. Fig. 1 and 2 show a state in which the generator 40 and the reduction gear 30 are disconnected, and fig. 3 shows a state in which the generator 40 and the reduction gear 30 are connected. As shown in fig. 3, when the movable portion 65 moves to the right from the state shown in fig. 1 and 2, the internal splines of the movable portion 65 mesh with the external splines of the first flange portion 62. Thereby, the first flange portion 62 is connected to the second flange portion 63 via the movable portion 65, and the engine drive shaft 42 is connected to the clutch shaft 61. Therefore, the generator 40 is connected to the reduction gear unit 30 via the clutch mechanism 60.

On the other hand, as shown in fig. 1 and 2, when the movable portion 65 moves to the left side from the state shown in fig. 2, the internal splines of the movable portion 65 disengage from the external splines of the first flange portion 62, and the connection between the first flange portion 62 and the second flange portion 63 is cut off. Therefore, the connection between the engine drive shaft 42 and the clutch shaft 61 is disconnected, and the connection between the generator 40 and the reduction gear unit 30 is disconnected.

As described above, in the clutch mechanism 60, the movable portion 65 is moved in the axial direction by the driving portion 66, and thus the connection and disconnection between the generator 40 and the reduction gear unit 30 can be switched. In the present embodiment, when the generator 40 and the reduction gear 30 are connected by the clutch mechanism 60, the power of the engine 2 is transmitted to the differential device 50 via the generator 40, the clutch mechanism 60, and the reduction gear 30. On the other hand, when the clutch mechanism 60 is disconnected from the generator 40, the power of the engine 2 is not transmitted to the differential device 50.

A synchronizer ring, not shown, is fixed to the movable portion 65. The synchronizer ring moves in the axial direction together with the movable portion 65. The synchronizer ring has a contact surface that comes into contact with the first flange portion 62 before the internal spline of the movable portion 65 meshes with the external spline of the first flange portion 62 when the movable portion 65 moves to the right side to connect the generator 40 to the reduction gear 30. Thereby, the synchronizer ring rotates in synchronization with the first flange portion 62 by the frictional force between the synchronizer ring and the first flange portion 62, and the engine drive shaft 42 rotates in synchronization with the clutch shaft 61. Therefore, the engine drive shaft 42 and the clutch shaft 61 can be connected via the movable portion 65 in a state where the engine drive shaft 42 and the clutch shaft 61 rotate in synchronization. Therefore, when the generator 40 and the reduction gear 30 are connected by the clutch mechanism 60, it is possible to suppress a large shock from being applied to the engine drive shaft 42 and the clutch shaft 61.

As shown in fig. 7, the motor unit 10 further has a reservoir 70. The reservoir 70 is located inside the gear housing 13. The reservoir 70 is open upward and can store oil O. In the present embodiment, the storage section 70 has, for example, a rectangular parallelepiped box shape having an upward opening. The oil O in the gear housing 13 is stored in the storage section 70. Here, in the present embodiment, as described above, the lower end portion of the ring gear 51 is immersed in the oil reservoir OR2, and therefore the oil O in the oil reservoir OR2 is lifted by the ring gear 51. Thus, the oil O lifted by the ring gear 51 is scattered in the gear housing portion 13 and easily accumulated in the reservoir portion 70. Therefore, the oil O in the gear housing 13 can be efficiently collected in the reservoir 70. A part of the oil O that falls after being supplied to the generator 40 by an oil pump, not shown, to be described later, and the like is also stored in the storage unit 70.

The reservoir 70 covers the right end of the motor shaft 22. That is, the right end of the motor shaft 22 is located inside the reservoir 70. Thus, at least a part of the radial gap between the motor shaft 22 and the axle AX in the opening on the right side of the motor shaft 22 is located inside the reservoir 70. Therefore, the oil O is accumulated in the reservoir 70, and when the oil level of the oil O in the reservoir 70 reaches the radial gap between the motor shaft 22 and the axle AX, the oil O in the reservoir 70 is sucked into the radial gap between the motor shaft 22 and the axle AX by the negative pressure. Thus, the oil O and the like scattered in the gear housing portion 13 can be efficiently collected by the ring gear 51 and supplied to the inside of the motor shaft 22. Therefore, according to the present embodiment, even if the axle AX is inserted into the hollow motor shaft 22, the supply amount of the oil O into the motor shaft 22 can be increased. This enables the motor 20 to be appropriately cooled.

In the present embodiment, the entire gap in the radial direction between the motor shaft 22 and the axle AX in the opening on the right side of the motor shaft 22 is located inside the reservoir 70. Therefore, the oil O stored in the reservoir 70 is more easily sucked into the motor shaft 22. The oil O sucked into the motor shaft 22 flows to the left side through a gap in the radial direction between the motor shaft 22 and the axle AX.

Here, according to the present embodiment, the motor shaft 22 has shaft through

holes

22a, 22b, 22c, and 22d that connect the inside of the motor shaft 22 and the outer peripheral surface of the motor shaft 22. Therefore, the oil O supplied into the motor shaft 22 is discharged radially outward of the motor shaft 22 through the shaft through

holes

22a, 22b, 22c, and 22 d. Thereby, the oil O can be supplied to the stator 24 and the

bearings

27a, 27 b. Therefore, the stator 24 can be appropriately cooled by the oil O, and lubricating oil can be appropriately supplied to the

bearings

27a and 27 b. In the present embodiment, the oil O discharged from the shaft through

holes

22a, 22b is supplied to the coil 26. The oil O discharged from the shaft through

holes

22c, 22d is supplied to the

bearings

27a, 27 b.

The oil O discharged from the shaft through

holes

22a, 22b, 22c, and 22d is supplied to each portion, and then falls into the oil reservoir OR1 of the motor housing 12. Among the oil O supplied into the motor shaft 22, the oil O not discharged from the shaft through

holes

22a, 22b, 22c, and 22d is discharged from the left opening of the motor shaft 22. The oil O discharged from the left opening of the motor shaft 22 falls to the left side of the bearing holding wall 15 in the oil reservoir OR1 of the motor housing 12. At least a part of the oil O stored in the motor housing 12, that is, at least a part of the oil O in the oil reservoir OR1 flows into the gear housing 13 through the oil passage 14 b. This allows the oil O supplied from the oil reservoir OR2 in the gear housing 13 to the motor 20 to be returned to the gear housing 13.

In the present embodiment, the motor drive gear 31 is housed inside the storage section 70. In the present embodiment, the upper end of the motor drive gear 31 protrudes upward from the opening of the reservoir 70, for example. As shown in fig. 7 and 8, in the present embodiment, the storage section 70 includes a bottom wall portion 71, axial

side wall portions

72 and 73, and front-rear direction

side wall portions

74 and 75. As shown in fig. 7, the bottom wall portion 71 extends rightward from a portion of the partition wall portion 14 above the oil passage 14 b. The bottom wall portion 71 is located above the oil level of the oil reservoir OR2 in the gear housing portion 13.

The

axial side walls

72, 73 extend upward from the axial ends of the bottom wall 71. The axial side wall portion 72 extends upward from the right end of the partition wall portion 14. The axial side wall portion 72 has a hole portion 72a that penetrates the axial side wall portion 72 in the axial direction. Although not shown, hole 72a has a circular shape centered on motor axis J1. The axle AX is inserted into the hole 72 a.

The axial side wall portion 73 extends upward from the left end of the bottom wall portion 71. In the present embodiment, the axial side wall portion 73 is a portion of the partition wall portion 14 that overlaps the axial side wall portion 72 when viewed in the axial direction. That is, in the present embodiment, a part of the wall portion constituting the reservoir portion 70 is a part of the partition wall portion 14. In this way, since the reservoir 70 is formed by using a part of the partition wall 14, the reservoir 70 can be easily formed. The axial side wall portion 73 is provided with a hole portion 14 a.

As shown in fig. 8, the front-rear

direction side walls

74, 75 extend upward from the front-rear direction both side ends of the bottom wall 71. The front-rear direction side wall portion 74 extends upward from the front end of the bottom wall portion 71. The front-rear direction side wall portion 74 connects front end portions of the axial

side wall portions

72, 73 to each other. The front-rear direction side wall portion 75 extends upward from the rear end of the bottom wall portion 71. The front-rear direction side wall portion 75 connects rear end portions of the axial

side wall portions

72, 73 to each other.

The bottom wall portion 71, the axial side wall portion 72, and the front-rear direction

side wall portions

74, 75 are each plate-shaped. The bottom wall portion 71, the axial side wall portion 72, and the front-rear direction

side wall portions

74, 75 are part of the same single component. In the present embodiment, the storage portion 70 can be easily manufactured by fixing one member having the bottom wall portion 71, the axial side wall portion 72, and the front-rear direction

side wall portions

74 and 75 to the partition wall portion 14.

The motor unit 10 further includes an oil pump not shown. The oil pump is, for example, a mechanical pump attached to the engine drive shaft 42. The oil pump sucks the oil O from the oil reservoir OR2 in the gear housing 13 and supplies the oil O to an oil passage, not shown, provided inside the engine drive shaft 42 and inside the clutch shaft 61. This enables cooling of the rotor 41 of the generator 40. The oil O supplied to the oil passage inside the engine drive shaft 42 is discharged to the outside of the engine drive shaft 42 from a shaft through hole connecting the oil passage inside the engine drive shaft 42 and the outer peripheral surface of the engine drive shaft 42. The discharged oil O is supplied to a stator 44 of the generator 40 and a bearing, not shown, that supports the engine drive shaft 42. This allows the stator 44 to be cooled and lubricating oil to be supplied to bearings, not shown. The oil O supplied to the stator 44 and the bearings, not shown, falls into the oil reservoir OR2 in the gear housing 13.

The oil pump also supplies oil O to the motor 20. The oil pump supplies oil O to the stator 24 from above via an oil passage, not shown, provided in an upper wall portion of the motor housing portion 12. This enables further cooling of the stator 24. The oil O supplied to the motor 20 by the oil pump falls into the oil reservoir OR1 in the motor housing 12.

In the present embodiment, the oil pump is driven by the power of the engine 2. Therefore, even in a state where the clutch mechanism 60 is disconnected from the generator 40, the oil pump can be freely driven as long as the engine 2 can be driven. Further, the oil pump may be an electric oil pump.

The power train 1 also has an inverter, not shown. An inverter, not shown, is electrically connected to the stator 24 of the motor 20 and the stator 44 of the generator 40. The power supplied to the

stators

24 and 44 can be adjusted by the inverter. The inverter is housed in an inverter case housing the inverter, for example. The inverter case is fixed to an outer side surface of the case 11. The inverter is controlled by an electronic control device not shown.

A vehicle equipped with the motor unit 10 is prepared to have three traveling modes, i.e., an EV mode, a serial mode, and a parallel mode. These traveling modes are alternatively selected by an electronic control device, not shown, in accordance with a vehicle state, a traveling state, a request output of a driver, and the like. Fig. 1 shows the powertrain 1 in the EV mode. Fig. 2 shows the powertrain 1 in series mode. Fig. 3 shows the powertrain 1 in parallel mode.

As shown in fig. 1, the EV mode is a running mode in which the vehicle is driven only by the motor 20 using the charging power of the battery 3 while keeping the engine 2 and the generator 40 stopped. The EV mode is selected when the running load is low or when the charge level of the battery is high. In the EV mode, the clutch mechanism 60 is in a state in which the generator 40 and the reduction gear 30 are disconnected. When the rotor 21 is rotated by the supply of electric power from the battery 3, the rotation of the motor shaft 22 is transmitted to the motor drive gear 31, the counter gear 32, the counter shaft 34, the drive gear 33, the ring gear 51, and the axle AX in this order. Thus, the axle AX and the wheel H can be rotated by the motor 20, and the vehicle can be driven.

As shown in fig. 2, the series mode is a running mode in which the vehicle is driven by the motor 20 using the electric power while the generator 40 is driven by the engine 2 to generate electric power. In the series mode, the electric power generated by the generator 40 is supplied to both the battery 3 and the motor 20, for example. This enables the battery 3 to be charged. The serial mode is selected when the running load is medium or when the charge level of the battery is low. In the series mode, the clutch mechanism 60 is in a state in which the generator 40 is disconnected from the reduction gear unit 30. In the series mode, the transmission of rotation from the motor 20 to the axle AX is the same as in the EV mode.

In the present embodiment, since the clutch mechanism 60 is provided, the transmission of the power of the motor 20 to the generator 40 and the engine 2 can be suppressed in the EV mode and the series mode. Therefore, it is possible to suppress an increase in load applied to the motor 20, and it is possible to appropriately generate power by the generator 40 in the series mode.

As shown in fig. 3, the parallel mode is a running mode in which the vehicle is driven mainly by the engine 2 and the driving of the vehicle is assisted by the motor 20 as necessary, and is selected in the case where the running load is high. In the parallel mode, the clutch mechanism 60 is in a state of connecting the generator 40 with the reduction gear 30. Thereby, the power of the engine 2 is transmitted to the axle AX via the generator 40, the clutch mechanism 60, the reduction gear device 30, and the differential device 50. More specifically, when the rotor 41 of the generator 40 is rotated by the engine 2, the rotation of the engine drive shaft 42 is transmitted to the first flange portion 62, the movable portion 65, the second flange portion 63, the clutch shaft 61, the engine drive gear 64, the counter gear 32, the counter shaft 34, the drive gear 33, the ring gear 51, and the axle AX in this order. Thus, the axle AX and the wheel H can be rotated by the engine 2, and the vehicle can be driven.

In parallel mode, rotation of the motor shaft 22 is transmitted from the motor drive gear 31 to the counter gear 32. This can assist the rotation of the engine 2 by the motor 20. As described above, according to the present embodiment, since the counter gear 32 meshes with both the engine drive gear 64 and the motor drive gear 31, both the power of the engine 2 and the power of the motor 20 are transmitted to the counter gear 32 in the parallel mode. Therefore, a power transmission path from the counter gear 32 to the axle AX can be provided through a power transmission path from the engine 2 to the axle AX and a power transmission path from the motor 20 to the axle AX. Thereby, the number of shafts and gears required to transmit power from the motor 20 and the engine 2 to the axle AX can be reduced. Therefore, the motor unit 10 can be further downsized and lightened.

In addition, according to the present embodiment, the reduction ratio of the rotation of the motor 20 can be changed by changing the number of teeth of the motor drive gear 31, and the reduction ratio of the rotation of the engine 2 can be changed by changing the number of teeth of the engine drive gear 64. That is, by changing the number of teeth of each drive gear, the reduction ratio of the motor 20 and the reduction ratio of the engine 2 can be changed individually so as to be different from each other. This allows the reduction gear ratio of the motor 20 and the reduction gear ratio of the engine 2 to be set to appropriate values. Therefore, the vehicle can be driven efficiently in any case where the vehicle is driven by either one or both of the motor 20 and the engine 2.

As described above, in the present embodiment, the oil pump, not shown, is driven by the power of the engine 2, and therefore is not driven in the EV mode in which the engine 2 is stopped. In this case, the oil O is not supplied to the motor 20 by the oil pump, and therefore cooling of the motor 20 may be insufficient. On the other hand, since the ring gear 51 is driven in any mode, cooling by the oil O lifted by the ring gear 51 can be performed in any mode. However, it is difficult to supply the oil O to the gap between the motor shaft 22 and the axle AX only by raising the oil O by the ring gear 51.

In contrast, according to the present embodiment, as described above, the oil O can be efficiently supplied to the gap between the motor shaft 22 and the axle AX through the reservoir portion 70. Therefore, the oil O lifted by the ring gear 51 can be efficiently collected and supplied to the motor 20. This makes it easy to sufficiently supply the oil O to the motor 20 even in the EV mode and the series mode in which the oil pump is not driven, and thus insufficient cooling of the motor 20 can be suppressed.

The present invention is not limited to the above embodiment, and other configurations may be adopted. The wall portion constituting the storage portion may not include a part of the partition wall portion. Only a part of the radial gap between the motor shaft and the axle in the opening on the right side of the motor shaft may be located inside the reservoir. The reservoir may also be supplied with oil O by an oil pump. The housing may not have a partition wall portion. The structure of the clutch mechanism is not particularly limited. The clutch mechanism may not be provided. In this case, the power of the engine may be used only for power generation by the generator without being transmitted to the differential device. The structure of the speed reducing mechanism is not particularly limited. The structure of the differential device is not particularly limited. In the reduction gear, the gear to which the motor drive gear is engaged and the gear to which the engine drive gear is engaged may be different gears. The structure of the generator is not particularly limited. The generator may not be provided. The oil pump may not be provided.

The vehicle on which the motor unit of the above embodiment is mounted is not particularly limited as long as the axle is rotated by the motor unit, and may be a vehicle other than a vehicle having the motor unit and the engine as power sources. For example, the motor unit of the above embodiment may be mounted on an Electric Vehicle (EV) without an engine. In addition, the respective configurations described in the present specification can be appropriately combined within a range not inconsistent with each other.

Claims

1. A motor unit for rotating an axle of a vehicle, wherein,

the motor unit includes:

a motor having a motor shaft that rotates about a motor axis;

a reduction gear connected to the motor shaft;

a differential device connected to the reduction gear device and configured to rotate the axle about a differential axis;

a housing having a motor housing portion that houses the motor and a gear housing portion that houses the reduction gear and the differential gear and houses oil therein; and

a reservoir portion that is opened upward in the vertical direction inside the gear housing portion and that is capable of storing oil,

the differential axis is coincident with the motor axis,

The motor shaft is a hollow shaft opened at both sides in the axial direction,

the axle is connected to the inside of the motor shaft,

one end of the motor shaft in the axial direction protrudes into the gear housing,

at least a part of a radial gap between the motor shaft and the axle in the opening on one axial side of the motor shaft is located inside the reservoir.

2. The motor unit according to claim 1,

the differential device has a ring gear that rotates about the differential axis,

an oil reservoir for storing oil is provided in a region below the gear housing portion in the vertical direction,

the end portion on the lower side in the vertical direction of the ring gear is immersed in the oil reservoir.

3. The motor unit according to claim 1 or 2, wherein,

the motor shaft has a shaft through hole connecting an inside of the motor shaft and an outer peripheral surface of the motor shaft.

4. The motor unit according to any one of claims 1 to 3,

the housing has a partition wall portion that partitions the motor housing portion and the gear housing portion,

a part of the wall portion constituting the storage portion is a part of the partition wall portion.

5. The motor unit according to claim 4,

oil is contained in the motor containing part,

the partition wall portion has an oil passage connecting an inside of the motor housing portion and an inside of the gear housing portion,

the oil in the motor housing section is movable into the gear housing section through the oil passage.