WO2019208081A1

WO2019208081A1 - Motor unit and vehicle drive device

Info

Publication number: WO2019208081A1
Application number: PCT/JP2019/013508
Authority: WO
Inventors: 山口　康夫; 久嗣藤原; 中村　圭吾; 隆宏檜皮
Original assignee: 日本電産株式会社
Priority date: 2018-04-27
Filing date: 2019-03-28
Publication date: 2019-10-31
Also published as: CN112088262A

Abstract

An embodiment of the present invention provides a motor unit which rotates an axle of a vehicle. The motor unit is provided with: a motor which has a motor shaft rotating about a motor axis; a transmitting mechanism which is connected to the motor shaft and which transmits the power of the motor to an output shaft; a housing which contains the motor and the transmitting mechanism; an oil passage provided within the housing; an electrically driven oil pump which circulates oil through the oil passage; and an oil cooler in which part of the oil passage is disposed and which cools the oil. The oil cooler is disposed on the upper part of the housing, which is on the side vertically opposite a road surface.

Description

Motor unit and vehicle drive device

The present invention relates to a motor unit and a vehicle drive device. This application is based on US Provisional Application No. 62 / 663,324 filed on Apr. 27, 2018 and Japanese Patent Application No. 2018-150702 filed on Aug. 9, 2018. This application claims the benefit of priority to that application. The entire contents of which are hereby incorporated by reference.

A motor unit that rotates the axle of a vehicle is known. The vehicle cooling device of Patent Document 1 is mounted on a vehicle including an electric motor, an inverter, and a power transmission mechanism, and cools oil in an oil circulation circuit.

JP 2017-114477 A

When installing a motor unit in a vehicle, the motor unit is often installed in a subframe. For this reason, it may be difficult to connect a motor unit and another apparatus by piping, a hose, etc.

In view of the above circumstances, an object of the present invention is to provide a motor unit and a vehicle drive device that can be easily connected to another device provided in a vehicle.

One aspect of the present invention is a motor unit that rotates an axle of a vehicle, the motor having a motor shaft that rotates about the motor shaft, and the motor shaft that is connected to the motor shaft, and transmits the power of the motor to the output shaft. A transmission mechanism, a housing that houses the motor and the transmission mechanism, an oil passage provided inside the housing, an electric oil pump that circulates oil through the oil passage, and a part of the oil passage. An oil cooler that cools the oil, and the oil cooler is disposed in an upper portion of the housing opposite to a road surface in a vertical direction.

According to another aspect of the present invention, the motor unit described above, a subframe that supports the motor unit and is attached to the vehicle, an inverter electrically connected to the motor unit, and the inverter are accommodated. An inverter case, wherein the sub-frame has a portion facing the motor unit from an axial direction and a front-rear direction of the vehicle, and the inverter case is disposed above the sub-frame. The oil cooler is disposed at least partially above the subframe, and can receive the coolant flowing through the inverter case.

According to the motor unit and the vehicle drive device of one aspect of the present invention, it is easy to connect to another device provided in the vehicle.

FIG. 1 is a schematic diagram showing a motor unit and a vehicle drive device of an embodiment mounted on a vehicle. FIG. 2 is a perspective view showing the motor unit and the vehicle drive device. FIG. 3 is a side view showing the motor unit and the vehicle drive device. FIG. 4 is a perspective view showing the motor unit. FIG. 5 is a cross-sectional view showing the motor unit. FIG. 6 is a diagram schematically showing the direction of oil flowing through the oil passage of the motor unit. FIG. 7 is a schematic view showing an oil passage of the motor unit. FIG. 8 is a schematic view showing the direction of oil flowing through the oil passage. FIG. 9 is a schematic view showing the direction of oil flowing through the oil passage. FIG. 10 is a schematic diagram illustrating an oil passage of a motor unit according to a modification of the embodiment.

The motor unit 1 and the vehicle drive device 10 of the present embodiment will be described with reference to the drawings. In the following description, the vertical direction is defined and described based on the positional relationship when the motor unit 1 of the present embodiment shown in each drawing is mounted on a vehicle 100 located on a horizontal road surface. 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 present embodiment, the upper side in the vertical direction is simply referred to as “upper side”, and the lower side in the vertical direction is simply referred to as “lower side”. The X-axis direction is a direction orthogonal to the Z-axis direction and is the front-rear direction of the vehicle 100 on which the motor unit 1 is mounted. In the present embodiment, the + X side is the front side of the vehicle 100, and the −X side is the rear side of the vehicle 100. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction, and is the left-right direction (vehicle width direction) of the vehicle 100. In the present embodiment, the + Y side is the left side of the vehicle 100, and the −Y side is the right side of the vehicle 100. The positional relationship in the front-rear direction is not limited to the positional relationship of the present embodiment, and the + X side may be the rear side of the vehicle 100 and the −X side may be the front side of the vehicle 100. In this case, the + Y side is the right side of the vehicle 100, and the −Y side is the left side of the vehicle 100.

The motor shaft J2 shown as appropriate in each drawing extends in the Y-axis direction, that is, the left-right direction of the vehicle. In the following description, unless otherwise specified, a direction parallel to the motor shaft J2 is simply referred to as “axial direction”. Of the axial directions, a direction from the motor 20 to the transmission mechanism 30 (to be described later) of the motor unit 1 is referred to as one axial direction, and a direction from the transmission mechanism 30 to the motor 20 is referred to as the other axial direction. Specifically, in the present embodiment, in one motor unit 1 located on the left side (+ Y side) of the vehicle 100 among a pair of motor units 1 described later, one axial side is the + Y side and the other axial side is -Y side. In the other motor unit 1 located on the right side (−Y side) of the vehicle 100, one axial side is the −Y side, and the other axial side is the + Y side. The radial direction around the motor shaft J2 is simply referred to as “radial direction”. Of the radial directions, a direction approaching the motor shaft J2 is referred to as a radially inner side, and a direction away from the motor shaft J2 is referred to as a radially outer side. The circumferential direction around the motor axis J2, that is, the circumference of the motor axis J2, is simply referred to as “circumferential direction”. In the present embodiment, the “parallel direction” includes a substantially parallel direction, and the “perpendicular direction” includes a substantially orthogonal direction.

As shown in FIG. 1, the vehicle 100 includes two

vehicle drive devices

10 and 101 as power generation means for rotating the axle. That is, the vehicle 100 has a power train, and the power train includes two

vehicle drive devices

10 and 101 and a battery (not shown). The vehicle 100 of the present embodiment is an electric vehicle (EV) that uses a motor as power generation means. The vehicle 100 includes a front vehicle drive device 101 and a rear vehicle drive device 10. The front vehicle drive device 101 drives the front left wheel and the front right wheel. The rear vehicle drive device 10 includes a pair of rear motor units 1. Of the pair of rear motor units 1, one motor unit 1 drives the rear left wheel, and the other motor unit 1 drives the rear right wheel.

The rear vehicle drive device 10 is disposed at a substantially central portion of the vehicle 100 in the vehicle width direction. The two motor units 1 of the vehicle drive device 10 face each other in the vehicle width direction and are arranged side by side in the vehicle width direction. The two motor units 1 have a symmetrical structure with respect to each other about a virtual vertical plane that includes the central axis J1 in the vehicle width direction of the vehicle 100 and is perpendicular to the motor axis J2.

As shown in FIGS. 2 and 3, the vehicle drive device 10 of this embodiment includes a motor unit 1, a subframe 2, an inverter 3, and an inverter case 4. The subframe 2 is attached to the vehicle 100. The sub frame 2 supports the motor unit 1. In the present embodiment, the subframe 2 also supports the inverter case 4. The subframe 2 includes a front frame portion 2a, a rear frame portion 2b, and a pair of horizontal frame portions 2c.

The front frame portion 2a extends in the axial direction (vehicle width direction) and faces the motor unit 1 from the front side. The front frame portion 2a comes into contact with a housing 11 (described later) of the motor unit 1 from the front side. The rear frame portion 2b extends in the axial direction and faces the motor unit 1 from the rear side. The rear frame portion 2b contacts the housing 11 of the motor unit 1 from the rear side. The motor unit 1 is sandwiched between the front frame part 2a and the rear frame part 2b from the front-rear direction.

A pair of horizontal frame part 2c is arrange | positioned at intervals in the axial direction. The pair of horizontal frame portions 2c extend in the front-rear direction and face the motor unit 1 from the axial direction. In the example of this embodiment, the horizontal frame portion 2 c faces the housing 11 of the motor unit 1 with a gap in the axial direction. However, the present invention is not limited thereto, and the horizontal frame portion 2c may contact the housing 11 of the motor unit 1 from the axial direction. The pair of motor units 1 are disposed between the pair of horizontal frame portions 2c in the axial direction. As described above, the subframe 2 has a portion facing the motor unit 1 from the axial direction and the front-rear direction.

The inverter 3 is electrically connected to the motor unit 1. In the present embodiment, the inverter 3 is electrically connected to the pair of motor units 1. The inverter 3 is electrically connected to a stator 26 of the motor 20 described later of the motor unit 1. The inverter 3 can adjust the power supplied to the stator 26. The inverter 3 is controlled by an electronic control device (not shown).

The inverter case 4 accommodates the inverter 3. That is, the inverter 3 is disposed inside the inverter case 4. The inverter case 4 has a container shape that can accommodate the inverter 3. In the example of the present embodiment, the inverter case 4 has a rectangular parallelepiped shape. However, the present invention is not limited to this, and the inverter case 4 may have a shape other than a rectangular parallelepiped shape. The inverter case 4 is disposed on the upper part of the subframe 2. The inverter case 4 is disposed at a substantially central portion in the axial direction of the subframe 2 and is supported by the subframe 2. The inverter case 4 has a water channel (not shown) through which the coolant flows. The water channel of the inverter case 4 is connected to a radiator (not shown) provided in the vehicle 100. The coolant cooled by the radiator is supplied to the water channel of the inverter case 4. As the coolant flows through the water channel of the inverter case 4, the inverter 3 is cooled.

The motor unit 1 rotates the axle of the vehicle 100. 4 to 7, the motor unit 1 includes a housing 11, a plurality of

bearings

14, 15, 16, a motor 20, a transmission mechanism 30, an oil passage 40, oil pumps 61, 62, An oil cooler 65, a first temperature sensor 70, a second temperature sensor (not shown), and a rotation sensor 80 are provided. The

bearings

14, 15, and 16 are, for example, ball bearings.

As shown in FIG. 5, the housing 11 houses the motor 20 and the transmission mechanism 30. The housing 11 includes a motor housing portion 12, a gear housing portion 13, and a partition wall portion 17. The motor housing portion 12 and the gear housing portion 13 face each other in the axial direction and are arranged side by side in the axial direction.

The motor housing portion 12 is a portion of the housing 11 that houses the motor 20. The motor housing portion 12 has a cylindrical shape extending in the axial direction. In this embodiment, the motor accommodating part 12 is a bottomed cylindrical shape. The motor housing portion 12 opens on one side in the axial direction. The motor housing part 12 has a peripheral wall part 12a and a bottom wall part 12b. The bottom wall portion 12 b holds the bearing 14. The bottom wall portion 12b supports the motor shaft 22 through the bearing 14 so as to be rotatable around the motor axis J2. That is, the housing 11 rotatably supports the motor shaft 22 via the bearing 14.

The gear housing portion 13 is a portion of the housing 11 that houses the transmission mechanism 30. The gear accommodating part 13 is a cylinder shape extended in an axial direction. The gear accommodating part 13 has the surrounding wall part 13a. The peripheral wall portion 13a holds the bearing 15 therein. The peripheral wall portion 13a supports the output shaft 38 via the bearing 15 so as to be rotatable around the motor axis J2. That is, the housing 11 rotatably supports the output shaft 38 via the bearing 15.

The partition wall 17 has a plate shape that extends in a direction perpendicular to the motor shaft J2. The plate surface of the partition wall portion 17 faces the axial direction. The partition wall portion 17 has an annular plate shape centered on the motor shaft J2. The partition wall portion 17 is disposed in the gear housing portion 13. The partition wall portion 17 is located on the other side in the axial direction from the bearing 15. The outer peripheral part of the partition wall part 17 is fixed to the inner peripheral surface of the peripheral wall part 13a. An inner peripheral portion of the partition wall portion 17 is connected to an outer peripheral portion of an internal gear 34 described later of the transmission mechanism 30. The partition wall part 17 has an oil circulation hole 17a that penetrates the partition wall part 17 in the axial direction. The oil circulation hole 17 a is disposed in at least the lower part of the partition wall portion 17. Only one oil circulation hole 17a may be provided in the partition wall 17 or a plurality of oil circulation holes 17a may be provided.

The motor 20 outputs torque that rotates the axle of the vehicle 100. Torque of the motor 20 is transmitted to the axle via the transmission mechanism 30. The motor 20 includes a rotor 21 and a stator 26. The rotor 21 includes a motor shaft 22, a rotor holder 23, a rotor core 24, and a rotor magnet 25.

The motor shaft 22 extends in the axial direction around the motor shaft J2. The motor shaft 22 is cylindrical. The motor shaft 22 is a hollow shaft that opens on both sides in the axial direction. The motor shaft 22 rotates about the motor shaft J2. The motor shaft 22 is supported by a pair of

bearings

14 and 16 so as to be rotatable around the motor axis J2. The bearing 14 supports an end portion on the other axial side of the motor shaft 22. The bearing 16 supports a portion on one side of the motor shaft 22 in the axial direction. The bearing 16 is held by a bearing holder 35 described later of the transmission mechanism 30.

The motor shaft 22 has a recess 22a. The recess 22a opens to an end surface on one axial side of the motor shaft 22, and is recessed from the end surface to the other axial side. The recess 22a has a hole shape extending in the axial direction. A connecting shaft 31 (described later) of the transmission mechanism 30 is fitted into the recess 22a. Of the motor shaft 22, the inner diameter of the portion located on the other axial side of the recess 22a is smaller than the inner diameter of the recess 22a. In the present embodiment, the largest inner diameter portion of the inner peripheral surface of the motor shaft 22 is the recess 22a. According to the present embodiment, it is possible to ensure a large thickness of the motor shaft 22 in a portion other than the recess 22 a of the motor shaft 22. Therefore, the rigidity of the motor shaft 22 can be increased.

The rotor holder 23 is fixed to the motor shaft 22. The rotor holder 23 has a portion located on the radially outer side of the motor shaft 22. The rotor holder 23 holds the rotor core 24 and the rotor magnet 25. The rotor holder 23 has a bottomed cylindrical shape. The rotor holder 23 opens to one side in the axial direction. The rotor holder 23 includes a bottom portion 23a, a cylinder portion 23b, and a sensor support portion 23c.

The bottom 23a is a ring extending in the circumferential direction around the motor shaft J2. In the present embodiment, the bottom portion 23a has a plate shape extending perpendicularly to the motor shaft J2, and the plate surface faces the axial direction. The bottom portion 23a has an annular plate shape. The inner peripheral portion of the bottom portion 23 a is fixed to the outer peripheral portion of the motor shaft 22. The axial position of the bottom 23 a is on one side in the axial direction with respect to the axial position of the bearing 14, and on the other side in the axial direction with respect to the axial position of the bearing 16.

The cylinder portion 23b extends in the axial direction. The cylinder portion 23b has a cylindrical shape centered on the motor shaft J2. A space is provided between the inner peripheral surface of the cylindrical portion 23 b and the outer peripheral surface of the motor shaft 22. Of the inner peripheral surface of the cylindrical portion 23b, the end portion on the other side in the axial direction is connected to the outer peripheral portion of the bottom portion 23a. The inner diameter of the cylindrical portion 23b increases as it goes from the portion connected to the bottom portion 23a toward one side in the axial direction. The inner peripheral surface of the cylindrical portion 23b has a tapered surface-shaped portion whose inner diameter increases as it goes toward one side in the axial direction. When viewed from the radial direction, the end portion on one side in the axial direction of the cylindrical portion 23b and the bearing 16 are disposed so as to overlap each other. When viewed from the radial direction, the end of the cylindrical portion 23b on the other side in the axial direction and the bearing 14 are disposed so as to overlap each other.

The sensor support portion 23c protrudes from the plate surface facing the other side in the axial direction of the bottom portion 23a to the other side in the axial direction. The sensor support 23c has a cylindrical shape that extends in the axial direction about the motor shaft J2. The sensor support portion 23c has a portion that protrudes to the other side in the axial direction than the end portion on the other side in the axial direction of the cylindrical portion 23b. A resolver rotor 80a, which will be described later, of the rotation sensor 80 is fixed to the other end of the sensor support 23c in the axial direction. In the illustrated example, the resolver rotor 80a is fixed to the outer peripheral surface of the sensor support portion 23c.

The rotor core 24 is fixed to the outer peripheral surface of the cylindrical portion 23b. The rotor core 24 has an annular shape that extends in the circumferential direction about the motor shaft J2. In the present embodiment, the rotor core 24 has a cylindrical shape extending in the axial direction. The rotor core 24 is, for example, a laminated steel plate configured by laminating a plurality of electromagnetic steel plates in the axial direction. The rotor core 24 has a holding hole 24 a that penetrates the rotor core 24 in the axial direction at the radially outer end of the rotor core 24. A plurality of holding holes 24 a are disposed at the radially outer end of the rotor core 24 at intervals in the circumferential direction. The rotor magnets 25 are respectively held in the plurality of holding holes 24a. The plurality of rotor magnets 25 are arranged in the circumferential direction at the radially outer end of the rotor core 24. The rotor magnet 25 is fixed to the radially outer end of the rotor core 24. In addition, the rotor magnet 25 may be comprised from the annular ring magnet.

The stator 26 faces the rotor 21 with a gap in the radial direction. The stator 26 is located on the radially outer side of the rotor 21. The stator 26 includes a stator core 27, an insulator (not shown), and a plurality of coils 28. The stator core 27 has an annular shape that extends in the circumferential direction about the motor shaft J2. In the present embodiment, the stator core 27 has a cylindrical shape extending in the axial direction. The stator core 27 is fixed to the inner peripheral surface of the motor housing portion 12. The inner peripheral portion of the stator core 27 faces the outer peripheral portion of the rotor core 24 with a gap in the radial direction. The stator core 27 is, for example, a laminated steel plate configured by laminating a plurality of electromagnetic steel plates in the axial direction. The insulator material is, for example, an insulating material such as resin. The plurality of coils 28 are attached to the stator core 27 via insulators. The lower end portion of the stator 26 is disposed in an oil storage portion 50 (described later) of the oil passage 40.

The transmission mechanism 30 is connected to the motor shaft 22 and transmits the power of the motor 20 to the output shaft 38. The transmission mechanism 30 is connected to an end portion on one side in the axial direction of the motor shaft 22. The transmission mechanism 30 decelerates the rotation of the motor 20 to increase the torque, and outputs the rotation as a rotation around the output shaft J4 of the output shaft 38. The transmission mechanism 30 is a speed reduction mechanism, and is a planetary gear mechanism in the present embodiment. The output shaft J4 of the output shaft 38 is disposed coaxially with the motor shaft J2. According to this embodiment, the motor unit 1 can be reduced in size.

The transmission mechanism 30 includes a connecting shaft 31, a sun gear 32, a planetary gear 33, an internal gear 34, a bearing holder 35, a carrier pin 36, a carrier 37, an output shaft 38, and a plurality of

bearings

39a and 39b. Have. The

bearings

39a and 39b are, for example, needle roller bearings.

The connecting shaft 31 has a cylindrical shape extending in the axial direction. The connection shaft 31 is a hollow shaft that opens on both sides in the axial direction. One end of the coupling shaft 31 in the axial direction is rotatably supported around the motor axis J2 by the output shaft 38 via the bearing 39a. That is, the connecting shaft 31 and the output shaft 38 are rotatable in the circumferential direction via the bearing 39a.

The connecting shaft 31 is inserted into the recess 22a at the other end in the axial direction. The connecting shaft 31 is fitted in the recess 22a at the other end in the axial direction. In the present embodiment, a portion located on one axial side of the end portion on the other axial side of the outer peripheral surface of the connecting shaft 31 and a portion located on one axial side of the inner peripheral surface of the recess 22a are: They fit in the circumferential direction so as not to rotate with each other. That is, the connecting shaft 31 and the motor shaft 22 are not mutually rotatable in the circumferential direction. According to this embodiment, the inner diameter of the recess 22a is large as described above. As the inner diameter of the recess 22a is larger, the outer diameter of the connecting shaft 31 fitted into the recess 22a can be increased. Therefore, the rigidity of the connecting shaft 31 can be increased while increasing the rigidity of the motor shaft 22 as described above.

In the present embodiment, the connecting shaft 31 is fitted such that the other end in the axial direction is movably movable in the axial direction with respect to the recess 22a. Specifically, the other axial end of the connecting shaft 31 is splined into the recess 22a. For this reason, the connecting shaft 31 is movable in the axial direction with respect to the motor shaft 22. The end surface of the coupling shaft 31 facing the other side in the axial direction is in contact with the bottom surface of the recess 22a facing the one side in the axial direction or is opposed with a gap. In the illustrated example, the inner diameter of the inner peripheral surface of the motor shaft 22 and the inner diameter of the inner peripheral surface of the connecting shaft 31 are substantially the same. Although not shown in FIGS. 5 and 6, a second orifice 58 described later is provided between the inside of the motor shaft 22 and the inside of the connecting shaft 31.

The sun gear 32 is provided on the connecting shaft 31. The sun gear 32 is an external gear whose central axis is the motor shaft J2. The sun gear 32 is positioned on one side in the axial direction from the recess 22a. The sun gear 32 is disposed in an intermediate portion located between the end portion on one side in the axial direction and the end portion on the other side in the axial direction in the outer peripheral portion of the connecting shaft 31. In the present embodiment, the connecting shaft 31 and the sun gear 32 are part of a single member. The sun gear 32 is a helical gear. In other words, the gear teeth of the sun gear 32 extend around the motor shaft J2 in the axial direction. When viewed from the radial direction, the gear teeth of the sun gear 32 extend while being inclined with respect to the motor shaft J2.

The planetary gear 33 is disposed radially outside the sun gear 32 and meshes with the sun gear 32. A plurality of planetary gears 33 are provided on the outer side in the radial direction of the sun gear 32 at intervals in the circumferential direction. That is, the transmission mechanism 30 has a plurality of planetary gears 33. In the present embodiment, the transmission mechanism 30 includes three planetary gears 33 that are arranged at equal intervals in the circumferential direction. However, the number of planetary gears 33 included in the transmission mechanism 30 is not limited to three.

The planetary gear 33 has an annular shape around the rotation axis J3. The planetary gear 33 is an external gear whose central axis is the rotation axis J3. The rotating shaft J3 is located radially outside the motor shaft J2 and extends in parallel with the motor shaft J2. The rotation axis J3 is also the center axis of the carrier pin 36. In the present embodiment, the planetary gear 33 has a cylindrical shape extending in the axial direction. The planetary gear 33 rotates about the rotation axis J3. That is, the planetary gear 33 rotates around the rotation axis J3. The planetary gear 33 rotates about the motor shaft J2. That is, the planetary gear 33 revolves around the motor shaft J2. The planetary gear 33 revolves while rotating around the sun gear 32.

The planetary gear 33 has a first gear portion 33a and a second gear portion 33b. The diameter (outer diameter) of the first gear portion 33a is larger than the diameter of the second gear portion 33b. That is, in this embodiment, the planetary gear 33 is a stepped pinion type. Therefore, the transmission mechanism 30 further increases the reduction ratio of the rotation of the motor 20. The first gear portion 33 a has a portion located on the radially outer side than the internal gear 34. The first gear portion 33 a has a portion facing the inner peripheral surface of the peripheral wall portion 13 a of the gear housing portion 13 with a gap from the radially inner side. When viewed from the axial direction, the first gear portion 33a and the partition wall portion 17 are arranged to overlap each other.

The first gear portion 33a has a cylindrical shape centered on the rotation axis J3. When viewed from the radial direction, the first gear portion 33a and the sun gear 32 are arranged to overlap each other. The first gear portion 33 a meshes with the sun gear 32. The diameter of the first gear portion 33 a is larger than the diameter of the sun gear 32. The first gear portion 33a is a helical gear. That is, the gear teeth of the first gear portion 33a extend around the rotation axis J3 in the axial direction. When viewed from the direction perpendicular to the rotation axis J3, the gear teeth of the first gear portion 33a extend while being inclined with respect to the rotation axis J3.

The second gear portion 33b is cylindrical with the rotation axis J3 as the center. The second gear portion 33 b meshes with the internal gear 34. The second gear portion 33b is a helical gear. That is, the gear teeth of the second gear portion 33b extend around the rotation axis J3 in the axial direction. When viewed from a direction orthogonal to the rotation axis J3, the gear teeth of the second gear portion 33b extend while being inclined with respect to the rotation axis J3.

Specifically, the second gear portion 33b has a meshing portion 33c and a fitting portion 33d. The meshing portion 33c and the fitting portion 33d are arranged side by side in the axial direction. When viewed from the radial direction, the meshing portion 33c and the internal gear 34 are arranged to overlap each other. The meshing portion 33c is a portion that meshes with the internal gear 34 in the second gear portion 33b. That is, the gear of the 2nd gear part 33b is provided in the outer periphery of the meshing part 33c. The meshing part 33c is located on the other side in the axial direction from the fitting part 33d. The diameter of the meshing part 33c is smaller than the diameter of the first gear part 33a. In the example of the present embodiment, the axial length of the meshing portion 33c is larger than the axial length of the first gear portion 33a. When viewed from the radial direction, the meshing portion 33 c is disposed so as to overlap with the end portion on the one axial side of the motor shaft 22, the end portion on the other axial side of the concave portion 22 a and the connecting shaft 31.

The fitting portion 33d is a portion that fits with the first gear portion 33a in the second gear portion 33b. In the present embodiment, the inner peripheral portion of the first gear portion 33a is fitted to the outer peripheral portion of the fitting portion 33d so as to be movable in the axial direction. That is, the first gear portion 33a has a portion that is movably fitted in the axial direction with respect to the second gear portion 33b. Specifically, the inner peripheral portion of the first gear portion 33a is spline-fitted to the outer peripheral portion of the fitting portion 33d. For this reason, the first gear portion 33a is movable in the axial direction with respect to the second gear portion 33b.

In the present embodiment, as described above, the other axial end of the connecting shaft 31 is spline-fitted into the recess 22a. The first gear portion 33a of the planetary gear 33 is spline-fitted with the second gear portion 33b. Therefore, when the motor unit 1 is manufactured, the assembly is assembled with the first gear portion 33a of the planetary gear 33 and the sun gear 32 of the connecting shaft 31 engaged with each other, and this assembly is assembled with the motor shaft 22 and the second gear portion. 33b can be attached. Therefore, assembly of the motor 20 and the transmission mechanism 30 is easy. In particular, as in the present embodiment, when the sun gear 32 and the first gear portion 33a are helical gears, the above configuration makes assembly easier.

The internal gear 34 has an annular shape centered on the motor shaft J2. The internal gear 34 is an internal gear whose central axis is the motor shaft J2. The internal gear 34 has a cylindrical shape extending in the axial direction. The internal gear 34 is disposed on the outer side in the radial direction of the planetary gear 33 and meshes with the planetary gear 33. In this embodiment, the internal gear 34 is arrange | positioned in the radial direction outer side of the meshing part 33c of the 2nd gear part 33b, and meshes with the meshing part 33c. The internal gear 34 is a helical gear. That is, the gear teeth of the internal gear 34 extend around the motor shaft J2 in the axial direction. When viewed from the radial direction, the gear teeth of the internal gear 34 are inclined and extend with respect to the motor shaft J2.

The internal gear 34 is fixed to the housing 11. The internal gear 34 is connected to the partition wall portion 17. Specifically, the end on the one axial side of the outer peripheral portion of the internal gear 34 is connected to the inner peripheral portion of the partition wall portion 17. In the present embodiment, the internal gear 34 and the partition wall portion 17 are part of a single member.

The bearing holder 35 has a flange portion 35a and a holder tube portion 35b. The flange portion 35a has a plate shape extending in a direction perpendicular to the motor shaft J2. The plate surface of the flange portion 35a faces the axial direction. The flange portion 35a has an annular plate shape centered on the motor shaft J2. The outer peripheral portion of the flange portion 35 a is fixed to the end portion on the other axial side of the internal gear 34. That is, the bearing holder 35 is fixed to the internal gear 34.

The holder cylinder portion 35b has a cylindrical shape extending in the axial direction around the motor shaft J2. One end of the holder tube portion 35b in the axial direction is connected to the inner peripheral portion of the flange portion 35a. A space is provided between the inner peripheral surface of the holder cylinder portion 35 b and the outer peripheral surface of the motor shaft 22. The holder cylinder portion 35b holds the bearing 16 therein. That is, the bearing holder 35 holds the bearing 16. The holder cylinder portion 35 b holds the motor shaft 22 via the bearing 16. The bearing holder 35 supports the motor shaft 22 through the bearing 16 so as to be rotatable around the motor axis J2.

The carrier pin 36 is disposed on the radially outer side of the sun gear 32 and the connecting shaft 31. A plurality of carrier pins 36 are provided on the outer side in the radial direction of the sun gear 32 at intervals in the circumferential direction. That is, the transmission mechanism 30 has a plurality of carrier pins 36. In the present embodiment, the transmission mechanism 30 includes three carrier pins 36 that are arranged at equal intervals in the circumferential direction.

The carrier pin 36 has a cylindrical shape extending in the axial direction around the rotation axis J3. The carrier pin 36 is a hollow pin that opens on both sides in the axial direction. The carrier pin 36 is inserted into the planetary gear 33. The carrier pin 36 extends in the planetary gear 33 in the axial direction. The carrier pin 36 rotatably supports the planetary gear 33 via a bearing 39b. That is, the planetary gear 33 is rotatable about the rotation axis J3 with respect to the carrier pin 36. The carrier pin 36 rotatably supports the second gear portion 33b via the bearing 39b. In the present embodiment, a plurality of bearings 39b are arranged in the axial direction between the carrier pin 36 and the second gear portion 33b.

The carrier 37 supports the carrier pin 36. The carrier 37 is fixed to the carrier pin 36. The carrier 37 rotates around the motor shaft J2 as the planetary gear 33 and the carrier pin 36 rotate (revolve) around the motor shaft J2.

The carrier 37 includes a first wall portion 37a, a second wall portion 37b, and a connecting portion 37c. The first wall portion 37a has a plate shape extending in a direction perpendicular to the motor shaft J2. The plate surface of the first wall portion 37a faces the axial direction. The first wall portion 37a has an annular plate shape centered on the motor shaft J2. The first wall portion 37 a supports the end portion on the other axial side of the carrier pin 36. The ends on the other axial side of the plurality of carrier pins 36 are fixed to the first wall portion 37a. The first wall portion 37a faces the flange portion 35a of the bearing holder 35 from one side in the axial direction. A space is provided between the first wall portion 37a and the flange portion 35a. The first wall portion 37a has a hole 37d that is located on the motor shaft J2 and penetrates the first wall portion 37a in the axial direction. An end on one axial side of the motor shaft 22 and an end on the other axial side of the connecting shaft 31 are inserted into the hole 37d. When viewed from the radial direction, the first wall portion 37 a is disposed so as to overlap with the end portion on one axial side of the motor shaft 22 and the end portion on the other axial side of the connecting shaft 31.

The second wall portion 37b is disposed on one side in the axial direction from the first wall portion 37a. The first wall portion 37a and the second wall portion 37b are arranged with a space therebetween in the axial direction. The planetary gear 33 is disposed between the first wall portion 37a and the second wall portion 37b in the axial direction. The second wall portion 37b has a plate shape that extends in a direction perpendicular to the motor shaft J2. The plate surface of the second wall portion 37b faces the axial direction. The second wall portion 37b has an annular plate shape centered on the motor shaft J2. The second wall portion 37 b supports the end portion on one side of the carrier pin 36 in the axial direction. End portions on one axial side of the plurality of carrier pins 36 are fixed to the second wall portion 37b. That is, the first wall portion 37a and the second wall portion 37b support both end portions of the carrier pin 36 in the axial direction. In the present embodiment, the second wall portion 37b is located on one axial side of the sun gear 32.

The connecting portion 37c extends in the axial direction and connects the first wall portion 37a and the second wall portion 37b. In this embodiment, the connection part 37c is plate shape extended in an axial direction. However, the present invention is not limited thereto, and the connecting portion 37c may have an axial shape that extends in the axial direction. The plate surface of the connecting portion 37c faces the radial direction. The end portion on the other axial side of the connecting portion 37c is connected to the outer peripheral portion of the first wall portion 37a. One end of the connecting portion 37c in the axial direction is connected to the outer peripheral portion of the second wall portion 37b. In this embodiment, the connection part 37c and the 1st wall part 37a are parts of a single member.

A plurality of connecting portions 37c are provided at intervals in the circumferential direction. In the present embodiment, the carrier 37 has three connecting portions 37c. The connecting portion 37c is disposed adjacent to the planetary gear 33 in the circumferential direction. The plurality of connecting portions 37c and the plurality of planetary gears 33 are alternately arranged in the circumferential direction. The connecting portion 37 c is disposed on the radially inner side of the planetary gear 33 with respect to the most radially outer portion. That is, the planetary gear 33 has a portion that protrudes radially outward from the connecting portion 37c. In the present embodiment, at least the first gear portion 33a of the first gear portion 33a and the second gear portion 33b protrudes radially outward from the connecting portion 37c.

The output shaft 38 is arranged coaxially with the motor shaft J2. In the present embodiment, the output shaft 38 has a cylindrical shape extending in the axial direction. The output shaft 38 is disposed on one side of the carrier 37 in the axial direction. The output shaft 38 is connected to the carrier 37. The output shaft 38 is connected to the second wall portion 37 b of the carrier 37 at the other axial end. In the present embodiment, the output shaft 38 and the second wall portion 37b are part of a single member and are integrally provided. That is, the output shaft 38 and a part of the carrier 37 are part of a single member. The output shaft 38 rotates about the motor axis J2 as the carrier 37 rotates about the motor axis J2.

A space is provided between the outer peripheral surface of the output shaft 38 and the inner peripheral surface of the peripheral wall portion 13 a of the gear housing portion 13. The output shaft 38 is supported by the peripheral wall portion 13 a via the bearing 15. In the illustrated example, the end portion on one side in the axial direction of the output shaft 38 projects from the peripheral wall portion 13a toward the one side in the axial direction. However, the present invention is not limited to this, and the output shaft 38 may not protrude from the peripheral wall portion 13a to the one side in the axial direction. The output shaft 38 is directly or indirectly connected to the axle of the vehicle 100.

In this embodiment, the circulation structure of the oil O includes an oil passage 40 and oil pumps 61 and 62. The oil passage 40 is provided inside the housing 11. The oil pumps 61 and 62 circulate the oil O through the oil passage 40. That is, in the present embodiment, the motor unit 1 includes the first oil pump 61 and the second oil pump 62 that circulate the oil O through the oil passage 40. That is, the motor unit 1 includes a plurality of oil pumps 61 and 62. The first oil pump 61 and the second oil pump 62 can supply the oil O to the transmission mechanism 30. In the present embodiment, the first oil pump 61 and the second oil pump 62 can supply the oil O to the transmission mechanism 30 through the inside of the motor shaft 22. The first oil pump 61 and the second oil pump 62 will be described later separately.

The oil passage 40 includes an oil passage portion 41 in the motor shaft, an oil passage portion 42 in the connecting shaft, an annular oil passage portion 43, a first radial oil passage portion 44, a second radial oil passage portion 45, The carrier pin internal oil passage portion 46, the connecting oil passage portion 47, the third radial oil passage portion 48, the fourth radial oil passage portion 49, and the oil storage portion 50 are provided.

As shown in FIG. 5, the oil passage portion 41 in the motor shaft extends in the axial direction inside the motor shaft 22. The oil passage portion 41 in the motor shaft is located on the motor shaft J2. The oil passage portion 41 in the motor shaft is configured by a through hole that penetrates the motor shaft 22 in the axial direction. The motor shaft oil passage 41 opens at the bottom of the recess 22a. That is, the end portion on one side in the axial direction of the oil passage portion 41 in the motor shaft opens to the bottom surface facing the one side in the axial direction of the recess 22a.

The connection shaft oil passage portion 42 extends in the axial direction inside the connection shaft 31. The connecting shaft oil passage portion 42 is located on the motor shaft J2. The connecting shaft internal oil passage portion 42 is configured by a through-hole penetrating the connecting shaft 31 in the axial direction. The connecting shaft oil passage portion 42 is connected to the motor shaft oil passage portion 41. In other words, the end portion on the other side in the axial direction of the coupling shaft oil passage portion 42 is connected to the end portion on the one side in the axial direction of the oil passage portion 41 in the motor shaft. In the example of this embodiment, the inner diameter of the connecting shaft oil passage portion 42 and the inner diameter of the motor shaft oil passage portion 41 are substantially the same. In this embodiment, since the motor shaft 22 is provided with the recess 22a as described above, the outer diameter of the connecting shaft 31 can be increased, so that the inner diameter of the connecting shaft 31 and the inner diameter of the motor shaft 22 can be made substantially the same. . Therefore, the pressure loss of the oil O flowing from the inside of the motor shaft 22 into the inside of the connecting shaft 31 can be reduced.

The annular oil passage portion 43 is disposed between the outer peripheral surface of the end portion on the other axial side of the connecting shaft 31 and the inner peripheral surface of the recess 22a. The annular oil passage 43 is a ring extending in the circumferential direction. The annular oil passage 43 is a cylindrical space centered on the motor shaft J2, and is provided in the recess 22a. The annular oil passage portion 43 is located on the other side in the axial direction from a portion where the end portion on the other side in the axial direction of the connecting shaft 31 and the recess 22a are fitted.

The first radial oil passage portion 44 is disposed at the other axial end of the connecting shaft 31 and extends in the radial direction, and opens to the connecting shaft inner oil passage portion 42 and the annular oil passage portion 43. The first radial oil passage 44 is a through hole that extends radially inside the connecting shaft 31 at the other axial end of the connecting shaft 31 and opens to the inner and outer peripheral surfaces of the connecting shaft 31. Consists of. In the present embodiment, a plurality of first radial oil passage portions 44 are provided at intervals in the circumferential direction.

The second radial oil passage portion 45 is disposed at the end portion on the one axial side of the motor shaft 22 and extends in the radial direction, and opens to the outer peripheral surface of the annular oil passage portion 43 and the motor shaft 22. The second radial oil passage 45 extends radially inside the motor shaft 22 at one end in the axial direction of the motor shaft 22, and opens to the inner peripheral surface of the recess 22 a and the outer peripheral surface of the motor shaft 22. It is constituted by a through-hole. The radially outer end of the second radial oil passage portion 45 opens toward the space between the first wall portion 37a along the axial direction, the flange portion 35a, and the bearing 16. In the present embodiment, a plurality of second radial oil passage portions 45 are provided at intervals in the circumferential direction.

The carrier pin oil passage 46 is provided inside the carrier pin 36 and opens to the end surface of the carrier pin 36 in the axial direction and the outer peripheral surface of the carrier pin 36. The carrier pin oil passage 46 has a pin axial oil passage 46a and a pin radial oil passage 46b.

The pin axial oil passage 46a extends in the axial direction inside the carrier pin 36. The pin axial direction oil passage 46a is located on the rotation axis J3. The pin axial oil passage 46a is formed by a through hole that penetrates the carrier pin 36 in the axial direction. The pin axial oil passage portion 46a opens on an end surface of the carrier pin 36 facing the one side in the axial direction and an end surface facing the other side of the axial direction.

The pin radial direction oil passage 46b extends inside the carrier pin 36 in a direction perpendicular to the rotation axis J3. The pin radial direction oil passage 46 b opens on the outer peripheral surfaces of the pin axial direction oil passage 46 a and the carrier pin 36. The pin radial direction oil passage portion 46 b extends through the inside of the carrier pin 36 in a direction orthogonal to the rotation axis J <b> 3, and is configured by a through hole that opens to the inner peripheral surface and outer peripheral surface of the carrier pin 36. Specifically, the pin radial direction oil passage portion 46b is disposed in the carrier pin 36 inside in the radial direction from the rotation axis J3, that is, in the direction away from the motor shaft J2 along the radial direction from the rotation axis J3. That is, the pin radial oil passage 46b extends from the portion connected to the pin axial oil passage 46a in a direction away from the motor shaft J2 along the radial direction. In the present embodiment, the carrier pin oil passage 46 has a plurality of pin radial oil passages 46b that are spaced apart from each other in the axial direction. The plurality of pin radial direction oil passage portions 46 b open toward the plurality of bearings 39 b provided on the outer peripheral portion of the carrier pin 36. According to the present embodiment, the oil O flowing inside the carrier pin 36 is stably supplied to the bearing 39b by the action of centrifugal force when the carrier pin 36 rotates (revolves) around the motor shaft J2.

The connecting oil passage portion 47 connects a portion of the carrier pin inner oil passage portion 46 that opens to the end face in the axial direction of the carrier pin 36 and the second radial oil passage portion 45. The connecting oil passage portion 47 connects the end portion on the other axial side of the pin axial oil passage portion 46 a and the radially outer end portion of the second radial oil passage portion 45. The connecting oil passage portion 47 is disposed between the first wall portion 37 a along the axial direction, the flange portion 35 a and the bearing 16. The connecting oil passage portion 47 is an annular space (chamber) centered on the motor shaft J2. That is, the connecting oil passage portion 47 is configured by an annular chamber provided between the first wall portion 37 a along the axial direction, the flange portion 35 a and the bearing 16.

In this embodiment, the oil O flowing through the motor shaft oil passage portion 41 is connected to the connecting shaft oil passage portion 42, the first radial oil passage portion 44, the annular oil passage portion 43, the second radial oil passage portion 45, and The oil flows into the carrier pin oil passage 46 through the connection oil passage 47. The oil O flowing into the carrier pin internal oil passage 46 flows out to the outer peripheral surface of the carrier pin 36 and lubricates and cools the bearing 39b located between the carrier pin 36 and the planetary gear 33. According to the present embodiment, the oil passage 40 has the annular oil passage portion 43 disposed in the recess 22a. Accordingly, when the motor unit 1 is manufactured, when the end portion on the other axial side of the connecting shaft 31 is fitted into the recess 22a of the motor shaft 22, the first radial oil passage 44 and the second radial direction are fitted. The work of aligning the oil passage 45 can be reduced. That is, since the first radial oil passage portion 44 and the second radial oil passage portion 45 are connected through the annular oil passage portion 43, the circumferential position of the first radial oil passage portion 44 and the second radial oil passage portion. The oil O is stably supplied from the connecting shaft inner oil passage portion 42 inside the connecting shaft 31 to the carrier pin inner oil passage portion 46 without matching the circumferential position of 45. Even if the axial position of the first radial oil passage portion 44 and the axial position of the second radial oil passage portion 45 do not coincide with each other, the same effect as described above can be obtained. In other words, according to the present embodiment, the oil O can be stably supplied from the connection shaft 31 to the members of the transmission mechanism 30.

The third radial oil passage portion 48 is disposed at a portion located on the other side in the axial direction from the concave portion 22a of the motor shaft 22, and extends in the radial direction. That is, the third radial oil passage portion 48 is disposed in a portion of the motor shaft 22 that is located on the other axial side than the end on the one axial side. The third radial oil passage portion 48 opens on the outer peripheral surfaces of the motor shaft oil passage portion 41 and the motor shaft 22. The third radial oil passage portion 48 extends through the inside of the motor shaft 22 in the radial direction, and includes a through hole that opens to the inner peripheral surface and the outer peripheral surface of the motor shaft 22. The third radial oil passage portion 48 is located between the pair of

bearings

14 and 16 that are arranged with a space therebetween in the axial direction. The third radial oil passage portion 48 is disposed in an intermediate portion located between both end portions in the axial direction of the motor shaft 22. The radially outer end of the third radial oil passage portion 48 opens toward the inner peripheral surface of the cylindrical portion 23 b of the rotor holder 23. When viewed from the radial direction, the rotor holder 23, the rotor core 24, the rotor magnet 25, the stator core 27, and the third radial oil passage portion 48 are arranged to overlap each other. In the present embodiment, a plurality of third radial oil passage portions 48 are provided at intervals in the circumferential direction. According to the present embodiment, the oil O flowing through the oil passage portion 41 in the motor shaft is supplied to each member of the motor 20 such as the rotor 21 and the stator 26 through the third radial oil passage portion 48. Thereby, each member of the motor 20 can be stably cooled and lubricated.

The fourth radial oil passage portion 49 is disposed in a portion of the connecting shaft 31 that is located on one side in the axial direction with respect to the recess 22a, and extends in the radial direction. That is, the fourth radial oil passage portion 49 is disposed in a portion of the connecting shaft 31 that is located on the one axial side relative to the end portion on the other axial side. The fourth radial oil passage portion 49 opens in the outer peripheral surface of the connection shaft oil passage portion 42 and the connection shaft 31. The fourth radial oil passage portion 49 is configured by a through hole that extends radially inside the connecting shaft 31 and opens to the inner peripheral surface and the outer peripheral surface of the connecting shaft 31. The fourth radial oil passage portion 49 is located between the pair of

bearings

15 and 16 that are arranged with a space therebetween in the axial direction. The fourth radial oil passage portion 49 is disposed in an intermediate portion located between both end portions in the axial direction of the connecting shaft 31. The radially outer end of the fourth radial oil passage portion 49 opens toward the planetary gear 33. The fourth radial oil passage portion 49 opens toward the outer peripheral portion of the meshing portion 33c of the second gear portion 33b. When viewed from the radial direction, the internal gear 34 and the planetary gear 33 and the fourth radial oil passage portion 49 are disposed so as to overlap each other. In the present embodiment, a plurality of fourth radial oil passage portions 49 are provided at intervals in the circumferential direction. According to the present embodiment, the oil O flowing through the connecting shaft oil passage portion 42 passes through the fourth radial oil passage portion 49, and each member of the transmission mechanism 30 such as the planetary gear 33, the internal gear 34, and the sun gear 32. To be supplied. Thereby, each member of the transmission mechanism 30 can be stably lubricated and cooled.

In the present embodiment, as described above, the oil O flowing inside the motor shaft 22 is supplied to the motor 20 and the transmission mechanism 30. According to this embodiment, the oil O can be stably supplied to the motor 20 and the transmission mechanism 30 through the motor shaft 22. That is, the oil O is distributed over a wide range by circulating in the motor shaft 22, and the oil O can be easily distributed to each member in the housing 11.

The oil storage part 50 is arranged at the lower part (bottom part) of the housing 11. The oil storage part 50 is located in the lower part of the housing 11. Oil O is stored in the oil storage unit 50. The oil reservoir 50 includes a motor oil reservoir 50a and a gear oil reservoir 50b. The motor oil storage part 50 a is a part of the oil storage part 50 that is located on the other side in the axial direction from the partition wall part 17. The lower part of the stator 26 is arrange | positioned at the motor oil storage part 50a. That is, the lower part of the stator 26 is immersed in the oil O of the motor oil storage part 50a.

The gear oil storage part 50 b is a part of the oil storage part 50 that is located on one side in the axial direction from the partition wall part 17. A rotation locus (not shown) around the motor shaft J2 of the planetary gear 33 is disposed in the gear oil storage unit 50b. Specifically, of the first gear portion 33a and the second gear portion 33b of the planetary gear 33, at least the rotation locus centering on the motor shaft J2 of the first gear portion 33a passes through the gear oil storage portion 50b. That is, the rotation locus centering on the motor shaft J <b> 2 of the planetary gear 33 passes through the oil storage unit 50. According to the present embodiment, when the planetary gear 33 passes through the oil storage unit 50, the oil O of the oil storage unit 50 is lifted up, and the oil O is also supplied to the upper portion of the housing 11. Thereby, lubrication and cooling of each member such as the transmission mechanism 30 can be stably performed.

The arrows OF1, OF2, OF3 shown in FIG. 6 simply represent the flow of the oil O in the housing 11. OF1 indicates the flow of oil O supplied from the oil cooler 65. The flow OF1 cools, for example, the stator 26 and the like. OF2 indicates the flow of the oil O supplied from the first oil pump 61. The flow OF2 cools, for example, the rotor 21 and the stator 26, and lubricates the sun gear 32, the planetary gear 33, the internal gear 34, and the

bearings

14, 15, 16, 39a, 39b, and the like. OF3 indicates the flow of the oil O supplied by the oil pumping action by the revolution of the planetary gear 33 around the motor shaft J2. The flow OF3 lubricates, for example, the sun gear 32, the planetary gear 33, the internal gear 34, the

bearings

15, 16, 39a, and 39b.

As shown in FIG. 7, the oil passage 40 further includes a first oil passage portion 51, a second oil passage portion 52, an oil chamber 53, a third oil passage portion 54, a first orifice 55, and a catch tank. 56, a fourth oil passage portion 57, a second orifice 58, a pump housing portion 59, and a strainer 60. That is, the motor unit 1 of the present embodiment includes the first orifice 55, the catch tank 56, the second orifice 58, and the strainer 60. The first orifice 55, the catch tank 56, the second orifice 58 and the strainer 60 are provided inside the housing 11.

The first oil passage portion 51 connects the first oil pump 61 and the inside of the motor shaft 22. The first oil passage portion 51 includes a check valve 51 a between the first oil pump 61 and the inside of the motor shaft 22. That is, the motor unit 1 includes a check valve 51 a inside the housing 11. The check valve 51a has a structure that allows the oil O to pass only in one direction by suppressing the back flow of the valve body by the back pressure of the fluid. Specifically, the check valve 51 a allows the flow of oil O from the first oil pump 61 toward the motor shaft 22 in the first oil passage 51, but from the motor shaft 22 to the first oil pump 61. The directed oil O flow is not allowed.

The first oil pump 61 is an electric oil pump. According to the present embodiment, the oil O can be stably supplied into the motor shaft 22 through the first oil passage portion 51 by the first oil pump 61 which is an electric oil pump. For example, unlike the present embodiment, when the first oil pump 61 is a mechanical oil pump coupled to the motor shaft 22, the oil O is not supplied into the motor shaft 22 when the rotation of the motor 20 is stopped. . Further, when the rotational speed of the motor 20 is low, oil is not easily supplied into the motor shaft 22. On the other hand, according to the present embodiment, even when the rotation of the motor 20 is stopped, for example, the first oil pump 61 is operated at the timing when the ignition of the vehicle 100 is turned on, and the oil is put into the motor shaft 22. O can be supplied. Even when the rotational speed of the motor 20 is low, a predetermined amount of oil O can be supplied into the motor shaft 22. The oil O can be supplied to the transmission mechanism 30 by the first oil pump 61. Accordingly, it is possible to reduce the load applied to the members of the transmission mechanism 30 when starting the motor.

As shown in FIGS. 2 to 6, the first oil pump 61 is disposed on the upper portion of the housing 11. According to the present embodiment, since the first oil pump 61 is disposed on the upper portion of the housing 11, it is easy to electrically connect the first oil pump 61 to the inverter 3. That is, the wiring (not shown) for connecting the inverter 3 and the first oil pump 61 can be easily routed, and the wiring length can be shortened. In the present embodiment, the first oil pump 61 is provided inside the housing 11. That is, since the first oil pump 61 is a built-in type, the entire first oil pump 61 and the oil passage 40 can be disposed in the housing 11. Therefore, for example, in accordance with this embodiment, it is possible to suppress a problem that oil leakage occurs from the oil passage or the electric oil pump outside the housing.

As shown in FIG. 7, the second oil passage portion 52 connects the second oil pump 62 and the inside of the motor shaft 22. According to the present embodiment, the oil O can be supplied more stably in the motor shaft 22 by the second oil pump 62. The second oil pump 62 is a mechanical oil pump connected to the motor shaft 22. As shown in FIG. 5, the second oil pump 62 is disposed on the bottom wall portion 12 b of the motor housing portion 12. The second oil pump 62 is disposed coaxially with the motor shaft 22 on the other axial side of the motor shaft 22. The second oil pump 62 is, for example, a trochoid pump. According to the present embodiment, the first oil pump 61 that is an electric oil pump can be selectively used according to the rotation state, temperature, and the like of the motor 20. For example, the operation of the first oil pump (electric oil pump) 61 is performed when the rotational speed of the motor 20 is stable at a low speed when the vehicle 100 is traveling, or when the temperature of the motor 20 and the oil O is low. The oil O may be supplied into the motor shaft 22 only by the second oil pump (mechanical oil pump) 62.

The amount of oil O discharged from the first oil pump 61 is smaller than the amount of oil O discharged from the second oil pump 62. In other words, the discharge amount of oil O discharged from the second oil pump 62 is larger than the discharge amount of oil O discharged from the first oil pump 61. Specifically, the cross-sectional area of the oil passage at the discharge port of the second oil pump 62 is larger than the cross-sectional area of the oil passage at the discharge port of the first oil pump 61. In the present embodiment, the second oil pump 62 can be used as a main pump, and the first oil pump 61 can be selectively used as a sub pump.

The first oil pump 61 can supply oil O to the second oil pump 62. In the present embodiment, the first oil pump 61 can supply the oil O to the second oil pump 62 through the oil chamber 53. In the control method of the motor unit 1 of the present embodiment, the oil O is supplied to the second oil pump 62 by the first oil pump 61 when the motor 20 is started. In general, when the rotation of the motor is stopped, no oil is supplied to the mechanical oil pump. For this reason, conventionally, the load applied to the mechanical oil pump at the time of starting the motor is large. On the other hand, according to the present embodiment, even when the rotation of the motor 20 is stopped, the second oil pump (mechanical oil pump) 61 is used by the first oil pump (electric oil pump) 61 when the motor 20 is started. Oil O can be supplied to the (type oil pump) 62. For example, the oil O can be supplied to the second oil pump 62 by the first oil pump 61 at the timing when the ignition of the vehicle 100 is turned on. Accordingly, it is possible to reduce the load applied to the second oil pump 62 when starting the motor.

The oil chamber 53 is disposed on the bottom wall portion 12b of the motor housing portion 12 and extends in the axial direction. The oil chamber 53 is located on the motor shaft J2. The oil chamber 53 is a space located between the oil passage portion 41 in the motor shaft and the second oil pump 62 in the axial direction. The oil chamber 53 faces the discharge port of the second oil pump 62. As shown in FIG. 7, the oil chamber 53 is disposed at a portion where the first oil passage portion 51 and the second oil passage portion 52 are connected. According to the present embodiment, the first oil passage portion 51 and the second oil passage portion 52 are merged in the oil chamber 53. Therefore, for example, compared with a configuration in which the

oil passage portions

51 and 52 are connected to the motor shaft 22, respectively. Thus, the structure of the oil passage 40 can be simplified. In the present embodiment, since the first oil passage 51 has the check valve 51a as described above, when the oil O is supplied into the motor shaft 22 by the second oil pump 62, the first oil passage 51 The oil O can be prevented from flowing back to the first oil pump 61 through the first oil pump 61. Further, since the first oil passage 51 is connected to the oil chamber 53 facing the discharge port instead of the suction port of the second oil pump 62, the oil O flowing through the first oil passage 51 is transferred to the second oil pump. Backflow to the upstream side of 62 can be suppressed.

The third oil passage portion 54 connects the first oil pump 61 and the oil cooler 65. That is, in the present embodiment, the oil path branches from the first oil pump 61 toward the downstream side. Specifically, the oil O discharged from the first oil pump 61 flows into the first oil passage portion 51 connected to the motor shaft 22 and the third oil passage portion 54 connected to the oil cooler 65. The third oil passage portion 54 is disposed on the upper portion of the housing 11. That is, the oil passage 40 has a portion that is disposed at the upper portion of the housing 11 by connecting the first oil pump 61 and the oil cooler 65. According to the present embodiment, as described above, the first oil pump 61 is disposed on the upper portion of the housing 11, and a portion of the oil passage 40 that connects the first oil pump 61 and the oil cooler 65 (that is, the third oil passage). The part 54) is also arranged at the top of the housing 11. Therefore, the length of the third oil passage portion 54 can be kept short, and the oil O can be efficiently cooled and circulated to the oil passage 40.

The first orifice 55 is provided in the third oil passage portion 54. The first orifice 55 narrows the oil passage of the third oil passage portion 54. Specifically, in the present embodiment, the inner diameter of the portion of the oil passage 40 located on the downstream side of the first orifice 55 is smaller than the inner diameter of the portion of the oil passage 40 located on the upstream side of the first orifice 55. According to the present embodiment, the pressure loss in the third oil passage portion 54 is increased by the first orifice 55, so that the oil O discharged from the first oil pump 61 flows preferentially to the first oil passage portion 51. It is. For this reason, for example, at the time of starting the motor where the necessity of cooling the oil O is low, the flow rate of the oil O flowing from the first oil pump 61 to the oil cooler 65 flows from the first oil pump 61 into the motor shaft 22. A large amount of oil O can be secured.

The catch tank 56 is disposed at the top of the motor 20. The catch tank 56 can temporarily store the oil O. A plurality of holes are provided in the bottom wall of the catch tank 56. The catch tank 56 stores the oil O and can be dropped onto the motor 20. The fourth oil passage portion 57 connects the oil cooler 65 and the catch tank 56. According to the present embodiment, the oil O cooled by the oil cooler 65 is supplied to the catch tank 56 through the fourth oil passage portion 57. By dripping the cooled oil O from the catch tank 56, the motor 20 can be efficiently cooled.

The second orifice 58 narrows the oil passage at the portion connecting the inside of the motor shaft 22 and the transmission mechanism 30. According to the present embodiment, the second orifice 58 increases the pressure loss in the portion of the oil passage 40 that connects the inside of the motor shaft 22 and the transmission mechanism 30, so that the oil O in the motor shaft 22 is transferred to the transmission mechanism. 30 is preferentially flowed to the motor 20. That is, since the amount of oil O required to cool the motor 20 is larger than the amount of oil O required to lubricate the transmission mechanism 30, the oil O flows preferentially to the motor 20. Thereby, each member of the motor 20 can be cooled and lubricated stably.

The first oil pump 61 is accommodated in the pump accommodating portion 59. The pump housing portion 59 is a space (chamber) provided in the wall portion of the housing 11. In the present embodiment, the first oil pump 61 has a substantially cylindrical shape, and the pump housing portion 59 that houses the first oil pump 61 is a substantially cylindrical space. The pump housing part 59 has a cylindrical hole shape extending in the axial direction. However, not limited to this, the pump housing portion 59 may have a shape other than the cylindrical hole shape. The pump housing portion 59 is disposed on the upper portion of the housing 11. The pump housing part 59 houses at least a part of the first oil pump 61. The inner diameter of the pump housing part 59 is larger than the outer diameter of the portion of the first oil pump 61 housed in the pump housing part 59. Oil O is stored in the pump housing portion 59. According to the present embodiment, the oil O can be efficiently circulated through the oil passage 40 by the first oil pump 61 while the arrangement space of the oil passage 40 near the first oil pump 61 is kept small.

The strainer 60 collects impurities from the oil O. The strainer 60 is at least partially disposed in the oil storage unit 50. The strainer 60 is at least partially immersed in the oil O of the oil storage unit 50. However, the present invention is not limited to this, and the strainer 60 may be provided in a portion of the oil passage 40 located between the first oil pump 61 and the second oil pump 62 and the oil storage unit 50, for example. The first oil pump 61 sucks oil O from the oil storage section 50 through the strainer 60. In the present embodiment, the second oil pump 62 also sucks the oil O from the oil storage unit 50 through the strainer 60. The first oil pump 61 sends the oil O sucked from the oil storage section 50 through the strainer 60 to the oil cooler 65. According to this embodiment, the strainer 60 can collect and remove impurities such as solid components in the oil O. Therefore, the motor 20 and the transmission mechanism 30 etc. operate stably. Since the first oil pump 61 pumps the oil O to the oil cooler 65, the cooling efficiency of the oil O is increased, and the motor 20 and the transmission mechanism 30 can be efficiently cooled and lubricated.

The oil cooler 65 has a water channel through which coolant flows. The oil cooler 65 is connected to the inverter case 4 by piping or a hose. The oil cooler 65 can receive the coolant flowing in the inverter case 4 inside. A part of the oil passage 40 is disposed in the oil cooler 65. The oil O is cooled by heat exchange between the coolant flowing through the water passage of the oil cooler 65 and the oil O flowing through a part of the oil passage 40. That is, the oil cooler 65 cools the oil O. According to the present embodiment, the temperature of the oil O circulating in the oil passage 40 can be lowered by the oil cooler 65. Accordingly, the motor 20 and the transmission mechanism 30 can be efficiently cooled by the cooled oil O. The oil cooler 65 has a plurality of fin portions exposed to the outside of the oil cooler 65. The oil O is cooled by heat exchange between the outside air and the oil O through the plurality of fin portions.

As shown in FIGS. 2 to 6, the oil cooler 65 is disposed in the upper portion of the housing 11 opposite to the road surface in the vertical direction. That is, the oil cooler 65 is disposed on the upper portion of the housing 11. The road surface is an upper surface of a road or the like on which the vehicle 100 travels or stops, that is, an upper surface of a road or the like on which the vehicle 100 is located. When the subframe 2, the motor unit 1, and the inverter case 4 are provided in the vehicle 100 as in the present embodiment, the inverter case 4 is arranged at the top of the subframe 2 in consideration of, for example, water intrusion from the road surface. Placed in. According to the present embodiment, the oil cooler 65 of the motor unit 1 is disposed on the top (top) of the housing 11, so that the oil cooler 65 can be easily connected to the inverter case 4. That is, it is easy to connect the oil cooler 65 and the inverter case 4 with pipes or hoses, and the coolant that has cooled the inverter 3 is easily drawn into the oil cooler 65. Further, the oil O cooled by the oil cooler 65 can be easily supplied to the motor 20 by dropping from the upper portion of the housing 11.

In the present embodiment, the first oil pump 61 is arranged in the front-rear direction of the oil cooler 65 and the vehicle 100. In the twin motor type in which the two motor units 1 are installed in the subframe 2 as in the present embodiment, the arrangement space for the members is reduced in the front-rear direction and the vehicle width direction (axial direction) of the vehicle 100 in the motor unit 1. Hard to secure. Specifically, since the motor unit 1 is sandwiched between the subframes 2 from the front-rear direction of the vehicle 100, a space for installing a member cannot be secured in a region adjacent to the motor unit 1 in the front-rear direction. In addition, since another motor unit 1, an axle, a part of the subframe 2, and the like are arranged in the vehicle width direction of the motor unit 1, members are installed in areas adjacent to the motor unit 1 in the vehicle width direction. The space to do is not secured. Therefore, as in the present embodiment, when the first oil pump 61 and the oil cooler 65 are arranged at the top of the motor unit 1 and these members are arranged in the front-rear direction of the vehicle 100, the first oil pump 61 and the oil cooler It is easy to secure a space for disposing the cooler 65. In the example of this embodiment, the vertical position of the oil cooler 65, the vertical position of the first oil pump 61, and the vertical position of the inverter case 4 are substantially the same. A first oil pump 61 is disposed between the oil cooler 65 and the inverter case 4 in the front-rear direction of the vehicle 100.

As shown in FIG. 3, at least a part of the oil cooler 65 is disposed above the subframe 2. According to the present embodiment, since the oil cooler 65 is disposed so as to protrude above the subframe 2, the oil cooler 65 and the inverter case 4 can be more easily connected by piping. In the present embodiment, the entire oil cooler 65 is disposed above the subframe 2.

As shown in FIG. 7, the first temperature sensor 70 is provided in the motor 20. In the present embodiment, the first temperature sensor 70 detects the temperature of the stator 26. That is, the first temperature sensor 70 detects the temperature of the motor 20. The first temperature sensor 70 is, for example, a thermistor. The first temperature sensor 70 is electrically connected to, for example, the inverter 3. According to the present embodiment, when the temperature of the motor 20 becomes equal to or higher than a predetermined value, the first oil pump 61 can be operated to cool the motor 20 and the like with the oil O.

Although not particularly illustrated, the second temperature sensor is disposed in a part of the oil passage 40. The second temperature sensor is disposed in the oil storage unit 50, for example. The second temperature sensor detects the temperature of the oil O. The second temperature sensor is electrically connected to, for example, the inverter 3. According to the present embodiment, when the temperature of the oil O in the oil passage 40 becomes equal to or higher than a predetermined value, the oil O is circulated by operating the first oil pump 61 and circulating the oil O through the oil passage 40. By cooling, each member of the motor unit 1 can be cooled with the oil O.

As shown in FIGS. 5 to 7, the rotation sensor 80 is provided at the end of the motor 20 in the axial direction. In the present embodiment, the rotation sensor 80 is disposed at the end on the other axial side of the motor 20. When viewed from the radial direction, the rotation sensor 80 and the bearing 14 are arranged to overlap each other. The rotation sensor 80 detects the rotation of the motor 20. In the present embodiment, the rotation sensor 80 is a resolver. The rotation sensor 80 includes a resolver rotor 80a and a resolver stator 80b. The resolver rotor 80 a is fixed to the rotor 21. In the present embodiment, the resolver rotor 80 a is fixed to the sensor support portion 23 c of the rotor holder 23. The resolver stator 80 b is fixed to the housing 11. In the present embodiment, the resolver stator 80 b is fixed to the bottom wall portion 12 b of the motor housing portion 12. The rotation sensor 80 is electrically connected to the inverter 3. According to the present embodiment, when the rotation speed of the motor 20 becomes a predetermined value or more, the first oil pump 61 is operated to circulate the oil O through the oil passage 40, whereby each member is made of oil O. Can be cooled.

8 indicates the flow of the oil O that circulates through the oil passage 40 when the first oil pump 61 and the second oil pump 62 are operating. For example, when the load of the motor 20 is larger than a predetermined value when the motor is started, when the vehicle 100 is traveling, etc., when the temperature of the motor 20 is higher than a predetermined value, and when the temperature of the oil O is higher than a predetermined value For example, the inverter 3 operates the first oil pump 61. The white arrow shown in FIG. 9 simply represents the flow of the oil O circulating through the oil passage 40 when the operation of the first oil pump 61 is stopped and the second oil pump 62 is operating. Yes. For example, when the load of the motor 20 is small below a predetermined value when the vehicle 100 is traveling, etc., when the temperature of the motor 20 is low below a predetermined value, and when the temperature of the oil O is low below a predetermined value, etc. The inverter 3 stops the operation of the first oil pump 61.

It should be noted that the present invention is not limited to the above-described embodiment, and, for example, as described below, the configuration can be changed without departing from the spirit of the present invention.

In the above-described embodiment, the motor unit 1 is a rear motor unit of the vehicle 100, but is not limited thereto. The motor unit 1 may be a front motor unit of the vehicle 100. Further, the shape of the subframe 2 is not limited to the shape described in the above embodiment.

In the above-described embodiment, the example in which the second oil pump 62 is a mechanical oil pump has been described, but the present invention is not limited thereto. The second oil pump 62 may be an electric oil pump. In this case, the first oil pump 61 and the second oil pump 62, which are electric oil pumps, can be selectively used as appropriate according to the rotational state and load of the motor 20, the temperature of the motor 20, the temperature of the oil O, and the like. For example, the second oil pump 62 may be used when the load on the motor 20 is larger than a predetermined value, and the first oil pump 61 may be used when the load on the motor 20 is smaller than a predetermined value. In this case, it is preferable that the second oil pump 62 is disposed on the upper portion of the housing 11.

FIG. 10 shows a modification of the motor unit 1 of the above-described embodiment. As in this modification, the motor unit 1 may not include the second oil pump 62. Further, the check valve 51 a may not be provided in the first oil passage portion 51. In this case, the structure of the motor unit 1 can be simplified while the operational effects described in the above-described embodiment are obtained.

In the above-described embodiment, the example in which the motor unit 1 includes the first temperature sensor 70 and the second temperature sensor has been described, but the present invention is not limited thereto. The motor unit 1 may not include any of the first temperature sensor 70 and the second temperature sensor. A plurality of first temperature sensors 70 may be provided. A plurality of second temperature sensors may be provided.

In the above-described embodiment, the example in which the motor unit 1 and the vehicle driving device 10 are mounted on an electric vehicle (EV) has been described, but the present invention is not limited thereto. The motor unit 1 and the vehicle drive device 10 may be mounted on, for example, a plug-in hybrid vehicle (PHEV), a hybrid vehicle (HEV), or the like.

In addition, in the range which does not deviate from the meaning of this invention, you may combine each structure (component) demonstrated by the above-mentioned embodiment, a modification, and a note, etc., and addition of a structure, omission, replacement, and other changes are possible. Is possible. The present invention is not limited by the above-described embodiments, but only by the claims.

DESCRIPTION OF SYMBOLS 1 ... Motor unit, 2 ... Sub-frame, 3 ... Inverter, 4 ... Inverter case, 10 ... Vehicle drive device, 11 ... Housing, 20 ... Motor, 22 ... Motor shaft, 30 ... Transmission mechanism, 38 ... Output shaft, 40 ... Oil passage, 50 ... Oil storage part, 59 ... Pump housing part, 60 ... Strainer, 61 ... First oil pump (electric oil pump), 65 ... Oil cooler, 100 ... Vehicle, J2 ... Motor shaft, O ... Oil

Claims

A motor unit for rotating the axle of a vehicle,
A motor having a motor shaft that rotates about the motor shaft;
A transmission mechanism connected to the motor shaft and transmitting the power of the motor to an output shaft;
A housing that houses the motor and the transmission mechanism;
An oil passage provided inside the housing;
An electric oil pump for circulating oil in the oil passage;
An oil cooler in which a part of the oil passage is arranged and cools the oil,
The oil cooler is a motor unit that is disposed in an upper portion of the housing on the opposite side to the road surface in the vertical direction.
The motor unit according to claim 1,
The electric oil pump is a motor unit disposed at an upper part of the housing.
The motor unit according to claim 2,
The electric oil pump is a motor unit arranged in the front-rear direction of the oil cooler and the vehicle.
The motor unit according to claim 2 or 3,
The oil passage has a portion arranged on an upper portion of the housing by connecting the electric oil pump and the oil cooler.
The motor unit according to any one of claims 2 to 4,
The oil passage has a pump housing portion in which the electric oil pump is housed,
A motor unit in which the oil is stored in the pump housing portion.
The motor unit according to any one of claims 1 to 5,
The electric oil pump is a motor unit provided inside the housing.
The motor unit according to any one of claims 1 to 6,
The oil passage is
An oil storage part disposed at a lower part of the housing and storing the oil;
A strainer for collecting impurities from the oil,
The electric oil pump is a motor unit that sends the oil sucked from the oil storage section through the strainer to the oil cooler.
The motor unit according to any one of claims 1 to 7,
A subframe that supports the motor unit and is attached to the vehicle;
An inverter electrically connected to the motor unit;
An inverter case in which the inverter is accommodated, and a vehicle drive device comprising:
The sub-frame has a portion facing the motor unit from the axial direction and the front-rear direction of the vehicle,
The inverter case is disposed on an upper part of the subframe,
The oil cooler is a vehicle drive device, wherein at least a part of the oil cooler is disposed above the subframe and can receive a coolant flowing in the inverter case.