CN112840537A

CN112840537A - motor unit

Info

Publication number: CN112840537A
Application number: CN201980062998.9A
Authority: CN
Inventors: 福永庆介; 宫田阳平; 村田大辅; 水谷真澄; 斋藤恒之; 铃木理世
Original assignee: Nidec Corp; Nidec Elesys Corp
Current assignee: Nidec Corp
Priority date: 2018-09-28
Filing date: 2019-09-26
Publication date: 2021-05-25
Anticipated expiration: 2039-09-26
Also published as: JPWO2020067280A1; DE112019004896T5; CN113765300B; CN112840537B; JP2023169192A; JP7342877B2; CN113765300A; WO2020067280A1

Abstract

A motor unit according to one embodiment of the present invention includes a motor, a transmission mechanism, a case, and an inverter unit. The transmission mechanism has: a motor drive shaft; a motor drive gear, which is fixed to the motor drive shaft; a countershaft, which extends along the secondary axis; a countershaft gear and a drive gear, which are fixed to the countershaft; a ring gear, which meshes with the drive gear , which rotates around the output axis; and an output shaft, which is connected with the ring gear and rotates around the output axis. The motor drive shaft is a hollow shaft opened on both sides in the axial direction of the motor axis. An output shaft passes through the inside of the motor drive shaft. The inverter unit is located directly above the motor. At least a portion of the inverter unit overlaps the countershaft gear when viewed in the axial direction of the motor axis.

Description

Motor unit

Technical Field

The present invention relates to a motor unit.

Background

In recent years, a drive device mounted on an electric vehicle has been actively developed. In japanese laid-open gazette: japanese patent application laid-open No. 2010-268633 describes a motor unit connected to a PDU (power drive unit) that houses an inverter. In recent years, a motor unit in which an inverter is integrated has been developed.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open gazette: japanese patent application laid-open No. 2010-268633

Disclosure of Invention

Problems to be solved by the invention

If the inverter is integrated with the motor unit, there is a problem that the size of the motor unit is likely to increase.

An object of one embodiment of the present invention is to provide a motor unit in which an inverter is integrated and which can be reduced in size.

Means for solving the problems

A motor unit according to an aspect of the present invention is mounted on a vehicle to drive the vehicle. The motor unit has: a motor; a transmission mechanism that transmits power of the motor and outputs the power from an output shaft; a housing that houses the motor and the transmission mechanism; and an inverter unit that supplies power to the motor. The transmission mechanism includes: a motor drive shaft extending along a motor axis and rotated by the motor; a motor drive gear fixed to the motor drive shaft and rotating about the motor axis; a secondary shaft extending along a secondary axis; a counter gear fixed to the counter shaft, meshed with the motor drive gear, and rotated about the counter axis; a drive gear fixed to the counter shaft and rotating about the counter axis; a ring gear engaged with the drive gear and rotating about an output axis; and the output shaft is connected with the gear ring and rotates around the output axis. The motor axis, the secondary axis and the output axis extend parallel to each other. The motor drive shaft is a hollow shaft that is open on both sides in the axial direction of the motor axis. The output shaft is introduced into the motor drive shaft. The secondary axis is located above the motor axis with respect to the direction of gravity. The inverter unit is located directly above the motor. At least a portion of the inverter unit overlaps the counter gear when viewed from the axial direction of the motor axis.

Effects of the invention

According to one embodiment of the present invention, a motor unit is provided in which an inverter is integrated and which can be reduced in size.

Drawings

Fig. 1 is a conceptual diagram of a motor unit according to an embodiment.

Fig. 2 is a perspective view of a motor unit according to an embodiment.

FIG. 3 is a side view of one embodiment of a motor unit.

Fig. 4 is an exploded perspective view of a motor unit according to an embodiment.

Fig. 5 is an exploded perspective view of a motor unit according to an embodiment.

Fig. 6 is a schematic cross-sectional view of the motor unit.

Detailed Description

Hereinafter, a motor unit according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. In the drawings below, in order to facilitate understanding of each structure, the actual structure may be different from the scale, the number, and the like of each structure.

In the following description, the direction of gravity is defined based on the positional relationship when the motor unit 10 is mounted on a vehicle 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 represents the vertical direction (i.e., the vertical direction), + Z direction is the upper side (the opposite side to the direction of gravity), and-Z direction is the lower side (the direction of gravity). Therefore, in the present specification, the term "upper side" means an upper side with respect to the direction of gravity. The X-axis direction is a direction perpendicular to the Z-axis direction, and indicates the front-rear direction of the vehicle on which the motor unit 10 is mounted, + X direction is the front of the vehicle, and-X direction is the rear of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and indicates the width direction (left-right direction) of the vehicle, + Y direction is the left direction of the vehicle, and-Y direction is the right direction of the vehicle.

Fig. 1 is a conceptual diagram of a motor unit 10 according to an embodiment. Fig. 2 is a perspective view of the motor unit 10. The motor axis J1, the sub axis J3, the output axis J4, the rotation axis J6, the 1 st central axis J7c, and the 2 nd central axis J7e, which will be described later, are virtual axes that do not actually exist.

The motor unit 10 is mounted on a vehicle, and drives the vehicle by rotating the wheel H. The motor unit 10 is mounted on, for example, an Electric Vehicle (EV). The motor unit 10 may be mounted on a vehicle having a motor as a power source, such as a Hybrid Electric Vehicle (HEV) or a plug-in hybrid electric vehicle (PHV).

As shown in fig. 1, the motor unit 10 includes a motor 1, a transmission mechanism (transaxle) 5, a case 6 housing the motor 1 and the transmission mechanism 5, an oil pump 96, an oil cooler 97, a parking lock mechanism 7, oil O, and an inverter unit 8.

(case)

The housing 6 is made of, for example, aluminum die casting. The housing 6 is formed by connecting a plurality of members arranged in the vehicle width direction. A housing space 6S for housing the motor 1 and the transmission mechanism 5 is provided inside the housing 6. The housing 6 holds the motor 1 and the transmission mechanism 5 in the housing space 6S. The housing space 6S is divided into a motor chamber 6A housing the motor 1 and a gear chamber 6B housing the transmission mechanism 5.

The housing 6 has: a motor housing 62 in which the motor chamber 6A is provided and which houses the motor 1; a gear housing section 63 in which a gear chamber 6B is provided and which houses the transmission mechanism 5; and a partition wall portion 61 that partitions the motor chamber 6A and the gear chamber 6B. The partition wall 61 is located between the motor housing 62 and the gear housing 63 in the axial direction.

An oil reservoir P in which the oil O is stored is provided in a lower region in the housing space 6S. A partition wall opening 61a is provided in a partition wall portion 61 that partitions the motor chamber 6A and the gear chamber 6B. The partition wall opening 61a communicates the motor chamber 6A and the gear chamber 6B. The oil O in the housing space 6S moves between the motor chamber 6A and the gear chamber 6B through the partition wall opening 61 a.

An oil passage 90 through which the oil supply O circulates is provided in the housing space 6S. The oil O is supplied from the oil reservoir P to each part of the motor unit 10 through the oil passage 90. The oil passage 90 will be described in detail later.

(oil)

The oil O is accumulated inside the casing. The oil O circulates through an oil passage 90 provided in the casing 6. The oil O is used for lubricating the transmission mechanism 5 and for cooling the motor 1. The oil O is accumulated in a lower region of the housing space 6S (i.e., the oil reservoir P). In order to achieve the functions of the lubricating oil and the cooling oil, it is preferable to use an oil similar to an Automatic Transmission lubricating oil (ATF) having a low viscosity as the oil O.

A part of the motor 1 is immersed in the oil O accumulated in the oil reservoir P. More specifically, a part of the stator 32 of the motor 1 is immersed in the oil O in the oil reservoir P. Thereby, the oil O cools the stator 32.

Further, a part of the transmission mechanism 5 is immersed in the oil O in the oil reservoir P. More specifically, a part of the ring gear 51 of the transmission mechanism 5 is immersed in the oil O in the oil reservoir P. The oil O accumulated in the oil reservoir P is lifted by the operation of the ring gear 51 and diffused into the gear chamber 6B. The oil O diffused into the gear chamber 6B is supplied to each gear of the transmission mechanism 5 in the gear chamber 6B so that the oil O spreads over the tooth surfaces of the gears. The oil O supplied to the transmission mechanism 5 for lubrication is dropped and collected in the oil reservoir P.

(oil circuit)

The oil passage 90 is provided in the housing 6. The oil passage 90 is formed across the motor chamber 6A and the gear chamber 6B of the housing space 6S. The oil passage 90 is a path of the oil O that is supplied from the oil reservoir P to the motor 1 and is guided to the oil reservoir P again.

In the present specification, the "oil passage" refers to a path of the oil O circulating in the housing space 6S. Therefore, the "oil passage" is a concept as follows: the oil supply device includes not only a "flow path" for forming a stable flow of oil stably in one direction, but also a path (for example, an oil reservoir P) where the oil supply temporarily stays and a path where the oil supply drops.

The oil passage 90 is provided with an oil pump 96 and an oil cooler 97. In the oil passage 90, the oil O circulates in the order of the oil reservoir P, the oil pump 96, the oil cooler 97, and the motor 1, and returns to the oil reservoir P.

The oil pump 96 is provided in the path of the oil passage 90 and pumps the oil O. The oil pump 96 is an electric pump driven by electricity. The oil pump 96 is fixed to the gear housing 63 of the housing 6.

As shown in fig. 2, the oil pump 96 is provided to the housing 6 and is housed in the oil pump housing hole 69. The oil pump receiving hole 69 extends in the axial direction. The oil pump receiving hole 69 opens to the left side (+ Y direction) in the vehicle width direction. An intake port (not shown) for taking the oil O into the oil pump 96 and a discharge port (not shown) for pressure-feeding the oil O to the downstream side are opened in the inner peripheral surface of the oil pump receiving hole 69.

The oil pump 96 includes a pump motor 96m and a pump mechanism portion (not shown) driven by the pump motor 96 m. The pump motor 96m is exposed outside the opening of the oil pump receiving hole 69. The pump mechanism portion is housed inside the oil pump housing hole 69.

The pump motor 96m has a rotational axis J6 parallel to the motor axis J1. That is, the pump motor 96m rotates about the rotation axis J6 parallel to the motor axis J1. The oil pump 96 having the pump motor 96m is easily elongated in the direction of the rotation axis J6. According to the present embodiment, by making the rotation axis J6 of the pump motor 96m parallel to the motor axis J1, the size of the motor unit 10 can be miniaturized in the radial direction of the motor axis J1.

The pump mechanism portion is, for example, a trochoid pump in which an external gear and an internal gear are meshed and rotate. In this case, the internal gear of the pump mechanism portion is rotated by the pump motor 96 m. A gap between an internal gear and an external gear of the pump mechanism portion is connected to the suction port and the discharge port.

As shown in fig. 1, the oil pump 96 sucks up the oil O from the oil reservoir P via a flow path provided in the casing. The oil pump 96 supplies the sucked oil O to the oil cooler 97.

The oil cooler 97 is provided in a path of the oil passage 90, and cools the oil O passing through the oil passage 90. The oil cooler 97 is fixed to the gear housing 63 of the housing 6. A refrigerant pipe 97j through which the refrigerant cooled by a radiator (not shown) passes is connected to the oil cooler 97. The oil O passing through the inside of the oil cooler 97 exchanges heat with the refrigerant passing through the refrigerant pipe 97j to be cooled. Further, an inverter unit 8 is provided in a path of the refrigerant pipe 97 j. That is, the inverter unit 8 and the oil cooler 97 are connected to each other by a pipe (a refrigerant pipe 97j) constituting a refrigerant passage. The refrigerant passing through the refrigerant pipe 97j cools not only the oil O passing through the oil cooler 97 but also the inverter unit 8.

The oil O having passed through the oil cooler 97 is supplied to the motor 1 above the motor chamber 6A via a flow path provided in the casing 6. The oil O supplied to the motor 1 flows along the outer circumferential surface of the motor 1 and the coil surface of the stator 32 from the upper side to the lower side, and takes heat from the motor 1. This enables the entire motor 1 to be cooled. The oil O that has cooled the motor 1 drops downward and is accumulated in the lower region in the motor chamber 6A. The oil O stored in the lower region of the motor chamber 6A moves to the gear chamber 6B through the partition wall opening 61a provided in the partition wall portion 61.

(Motor)

The motor 1 is a motor generator having both a function as an electric motor and a function as a generator. The motor 1 mainly functions as an electric motor to drive the vehicle, and functions as a generator during regeneration.

As shown in fig. 1, the motor 1 has a rotor 31 and a stator 32 surrounding the rotor 31. The rotor 31 is rotatable about a motor axis J1. The stator 32 is annular. The stator 32 surrounds the rotor 31 from radially outside of the motor axis J1.

The rotor 31 is fixed to a motor drive shaft 11 described later. The rotor 31 rotates about a motor axis J1. The rotor 31 has a rotor core and a rotor magnet held by the rotor core.

The stator 32 has a stator core and a coil. The stator core has a plurality of teeth protruding radially inward of the motor axis J1. The coils are wound around the teeth of the stator core.

The motor 1 is connected to an inverter 8 a. The inverter 8a converts a direct current supplied from a battery, not shown, into an alternating current, and supplies the alternating current to the motor 1. The respective rotation speeds of the motor 1 are controlled by controlling the inverter 8 a.

(transfer mechanism)

The transmission mechanism 5 transmits the power of the motor 1 and outputs the power from the output shaft 55. The transmission mechanism 5 incorporates a plurality of mechanisms that transmit power between the drive source and the driven device.

The transmission mechanism 5 includes a motor drive shaft 11, a motor drive gear 21, a counter shaft 13, a counter gear (large gear portion) 23, a drive gear (small gear portion) 24, a ring gear 51, an output shaft (axle) 55, and a differential device (differential gear) 50.

The gears and the shafts of the transmission mechanism 5 are rotatable about any one of the motor axis J1, the sub axis J3, and the output axis J4. In the present embodiment, the motor axis J1, the secondary axis J3, and the output axis J4 extend parallel to each other. In addition, the motor axis J1, the sub axis J3, and the output axis J4 are parallel to the width direction of the vehicle. In the following description, the axial direction refers to the axial direction of the motor axis J1. That is, the axial direction refers to a direction parallel to the motor axis J1 and refers to the vehicle width direction.

The motor drive shaft 11 extends along a motor axis J1. The motor drive shaft 11 is fixed to the rotor 31. The motor drive shaft 11 is rotated by the motor 1. A motor drive gear 21 is fixed to the motor drive shaft 11.

The motor drive shaft 11 extends in the axial direction about a motor axis J1. The motor drive shaft 11 is a hollow shaft that opens on both sides in the axial direction of the motor axis J1. The outer shape of the motor drive shaft 11 as viewed in the axial direction is a cylindrical shape centered on the motor axis J1. The motor drive shaft 11 is bearing-supported so as to be rotatable about a motor axis J1. An output shaft 55 is inserted into the motor drive shaft 11.

The motor drive gear 21 is fixed to the motor drive shaft 11. The motor drive gear 21 rotates with the motor drive shaft 11 about the motor axis J1.

The secondary shaft 13 extends along a secondary axis J3. The countershaft 13 rotates about a countershaft axis J3. The counter shaft 13 is rotatably held by a housing (not shown) that houses the transmission mechanism 5, for example, via a bearing (not shown). A counter gear 23, a drive gear 24, and a parking lock gear 7a are fixed to the counter shaft 13.

The counter gear 23 is fixed to the counter shaft 13. The counter gear 23 rotates together with the counter shaft 13 about the counter axis J3. The counter gear 23 meshes with the motor drive gear 21.

The drive gear 24 is fixed to the counter shaft 13. Drive gear 24 rotates with countershaft 13 and countershaft gear 23 about countershaft axis J3. The drive gear 24 is disposed on the opposite side of the counter gear 23 from the motor 1 in the axial direction.

The parking lock gear 7a is a part of the parking lock mechanism 7. The parking lock gear 7a is fixed to the counter shaft 13. The parking lock gear 7a rotates about the secondary axis J3 together with the counter shaft 13, the counter gear 23, and the drive gear 24. The parking lock gear 7a is disposed between the counter gear 23 and the drive gear 24 in the axial direction.

The ring gear 51 is fixed to the differential device 50. The ring gear 51 rotates about the output axis J4. The ring gear 51 meshes with the drive gear 24. The ring gear 51 transmits the power of the motor 1 transmitted via the drive gear 24 to the differential device 50.

The differential device 50 is a device for transmitting torque output from the motor 1 to the wheels H of the vehicle. The differential device 5 has the following functions: when the vehicle turns, the same torque is transmitted to the output shafts 55 of the left and right wheels while absorbing the speed difference between the left and right wheels H.

The differential device 50 has a gear housing (not shown) fixed to the ring gear 51, a pair of pinion gears (not shown), a pinion shaft (not shown), and a pair of side gears (not shown). The gear housing rotates together with the ring gear 51 about the output axis J4. The gear housing houses a pair of pinions, a pinion shaft, and a pair of side gears. The pair of pinions are bevel gears opposite to each other. A pair of pinion gears are supported on the pinion shaft. The pair of side gears are bevel gears vertically meshed with the pair of pinions. The pair of side gears are fixed to the output shaft 55, respectively.

The output shaft 55 rotates about an output axis J4. In the motor unit 10, a pair of output shafts 55 are provided. A pair of output shafts 55 are connected at one end portion to the side gears of the differential device 50, respectively. That is, the output shaft 55 is connected to the ring gear 51 via the differential device 50. The power of the motor 1 is transmitted to the output shaft 55 via the gears. In addition, the pair of output shafts 55 protrude outward of the housing 6 at the other end portions, respectively. A wheel H is mounted on the other end of the output shaft 55. The output shaft 55 outputs power to the outside (to the road surface via the wheels H).

In the present embodiment, the output axis J4 coincides with the motor axis J1. One of the pair of output shafts 55 passes through the inside of the motor drive shaft 11, which is a hollow shaft. Therefore, the motor unit 10 of the present embodiment can be reduced in size in the radial direction of the motor axis J1, as compared with a motor unit having a structure in which the motor axis J1 and the output axis J4 are not coaxially arranged.

Fig. 3 is a side view of one embodiment of the motor unit 10.

The transmission mechanism 5 constitutes a power transmission path from the motor 1 to the output shaft 55. In the power transmission path of the transmission mechanism 5, the power of the motor 1 is first transmitted from the motor drive gear 21 to the counter gear 23. The counter gear 23 is disposed coaxially with the drive gear 24 and rotates together with the drive gear 24. The power of the motor 1 is transmitted from the drive gear 24 to the ring gear 51, and is transmitted to the output shaft 55 via the differential device 50.

(positional relationship of axes)

As shown in fig. 3, the sub-axis J3 is located above the motor axis J1. Further, since the motor axis J1 coincides with the output axis J4, the sub axis J3 is located above the output axis J4. According to the present embodiment, the centers of the counter gear 23 and the drive gear 24 are arranged offset from the centers of the motor 1 and the ring gear 51 in the vertical direction when viewed from the axial direction. Since the drive gear 24 and the ring gear 51 mesh with each other, the absolute distance therebetween is uniquely determined. Therefore, by disposing the motor axis J1 and the sub axis J3 so as to be offset in the vertical direction, the dimension components of the sub axis J3 and the motor axis J1 in the vehicle longitudinal direction can be reduced. As a result, the size of the motor unit 10 in the vehicle front-rear direction can be reduced, and a large impact area can be ensured in the vehicle.

In the present embodiment, the counter gear 23 and the drive gear 24 are located above the motor axis J1. That is, the lower ends of the counter gear 23 and the drive gear 24 are both located above the motor axis J1. Therefore, the drive gear 24 can be disposed to overlap the ring gear 51 in a large size when viewed in the vertical direction, and the dimension of the motor unit 10 in the vehicle longitudinal direction can be further reduced in size.

As shown in fig. 3, a line segment virtually connecting the motor axis J1 and the sub axis J3 is a 1 st line segment L1 when viewed from the axial direction. The 1 st line segment L1 makes an angle α with a vertical line VL extending in the vertical direction. The angle α is preferably within 45 °. That is, the 1 st line segment L1 preferably extends in a direction within 45 ° from the vertical direction (the direction of gravity). This enables further reduction in the vehicle longitudinal dimension of the motor unit 10. Further, the angle α is more preferably within 20 °. That is, the 1 st line segment L1 more preferably extends in a direction within 20 ° from the vertical direction. This enables further reduction in the vehicle longitudinal dimension of the motor unit 10.

The sub-axis J3 is located on the rear side of the vehicle (in the (-X direction) with respect to the motor axis J1. As described above, a part of the ring gear 51 is immersed in the oil O in the oil reservoir P, and the oil O is lifted by the ring gear 51. When the vehicle advances, the ring gear 51 rotates in the direction of rotation T1 shown in fig. 3. The rotation direction T1 is a direction in which the ring gear 51 rotates to the upper side on the vehicle rear side. Therefore, the oil O lifted by the ring gear 51 is more effectively scattered on the vehicle rear side. According to the present embodiment, by positioning the sub-axis J3 on the rear side of the vehicle with respect to the motor axis J1, the oil O kicked up by the ring gear 51 can be efficiently supplied to the counter gear 23 and the drive gear 24. This improves the lubricity of the tooth surfaces of the counter gear 23 and the drive gear 24, thereby improving the power transmission efficiency of the transmission mechanism 5.

As shown in fig. 3, the oil pump 96 is located above the motor axis J1. That is, the lower end of the oil pump 96 is located above the motor axis J1. According to the present embodiment, the dimension of the motor unit 10 in the vehicle longitudinal direction can be further reduced as compared with the case where the oil pump and the motor axis J1 are arranged in the vehicle longitudinal direction. As a result, the size of the motor unit 10 in the vehicle front-rear direction can be reduced, and a large impact area can be ensured in the vehicle.

The oil pump 96 is disposed diagonally upward in front of the vehicle with respect to the motor axis J1. That is, the oil pump 96 is located above the motor axis J1 and on the front side (+ X direction) of the vehicle relative to the motor axis J1. As described above, the counter gear 23 and the drive gear 24 are located on the vehicle rear side (-X direction) with respect to the motor axis J1 on the upper side of the motor axis J1. Therefore, in the present embodiment, the oil pump 96, the counter gear 23, and the drive gear 24 can be arranged offset in the front-rear direction of the vehicle above the motor axis J1. This can reduce the size of the motor unit 10.

As described above, the oil pump 96 has the pump motor 96m that rotates about the rotation axis J6 parallel to the motor axis J1. As shown in fig. 3, a line segment virtually connecting the motor axis J1 and the rotation axis J6 is a 2 nd line segment L2 when viewed from the axial direction. The 2 nd line segment L2 makes an angle β with a vertical line VL extending in the vertical direction. The angle β is preferably within 45 °. That is, the 2 nd line segment L2 preferably extends in a direction within 45 ° from the vertical direction. This enables further reduction in the vehicle longitudinal dimension of the motor unit 10. Further, the angle β is more preferably within 35 °. That is, the 2 nd line segment L2 more preferably extends in a direction within 35 ° from the vertical direction. This enables further reduction in the vehicle longitudinal dimension of the motor unit 10.

The oil cooler 97 is located above the motor axis J1. That is, the lower end of the oil cooler 97 is located above the motor axis J1. According to the present embodiment, the dimension of the motor unit 10 in the vehicle longitudinal direction can be further reduced as compared with the case where the oil cooler and the motor axis J1 are arranged in the vehicle longitudinal direction.

The oil cooler 97 is disposed adjacent to the oil pump 96 on the upper side of the motor axis J1. The oil cooler 97 and the oil pump 96 are connected to each other via a flow path provided in the housing 6. By disposing the oil cooler 97 and the oil pump 96 adjacent to each other, a flow path connecting the oil cooler 97 and the oil pump 96 can be shortened. This can shorten the flow path constituting the oil passage 90, and can improve the circulation efficiency of the oil O in the oil passage 90.

The oil cooler 97 is located on the front side (+ X direction) of the vehicle relative to the motor axis J1. That is, the oil cooler 97 is disposed diagonally upward in the front of the vehicle with respect to the motor axis J1. According to the present embodiment, the oil cooler 97 can be cooled down by air when the vehicle is moving forward, and the cooling efficiency of the oil cooler 97 for the oil O can be improved.

(parking lock mechanism)

The parking lock mechanism 7 is driven in accordance with a shift operation by the driver. The parking lock mechanism 7 is switched between a locked state in which transmission of power in the transmission mechanism 5 is restricted and an unlocked state in which the restriction is released.

As shown in fig. 3, the parking lock mechanism 7 has a parking lock gear 7a, a parking lock arm 7b, an arm support shaft 7e, a parking lock actuator 7c, and a parking lock power transmission mechanism 7 d.

The parking lock gear 7a is fixed to the counter shaft 13. The parking lock gear 7a rotates together with the counter shaft 13 about the counter axis J3. The parking lock gear 7a has a plurality of teeth portions projecting radially outward of the sub-axis J3 and arranged in the circumferential direction of the sub-axis J3 on the outer circumferential surface thereof.

The parking lock arm 7b has a plate shape extending along a plane perpendicular to the axial direction. The parking lock arm 7b is rotatably supported by an arm support shaft 7e centering on a 2 nd central axis J7e extending in the axial direction. The parking lock arm 7b extends upward from the arm support shaft 7 e.

The parking lock arm 7b extends along the outer peripheral surface of the parking lock gear 7 a. The parking lock arm 7b is opposed to the tooth portion of the parking lock gear 7a in the radial direction of the sub axis J3. The parking lock arm 7b has an engaging portion 7ba opposed to the tooth portion of the parking lock gear 7 a. The engagement portion 7ba projects toward the radially inner side of the minor axis J3. The meshing portion 7ba meshes with the tooth portion of the parking lock gear 7 a. That is, the parking lock arm 7b is engaged with the parking lock gear at the engaging portion 7 ba.

The parking lock arm 7b is driven by the parking lock actuator 7c and rotates within a predetermined range around the 2 nd center axis J7 e. When the parking lock mechanism 7 is locked by the operation of the driver, the parking lock arm 7b rotates counterclockwise about the 2 nd center axis J7e in fig. 3, and the meshing portion 7ba meshes with the tooth portion of the parking lock gear 7 a. This suppresses the rotation of the counter shaft 13, and restricts the transmission of power in the transmission mechanism 5. On the other hand, when the parking lock mechanism 7 is in the unlocked state by the driver's operation, the parking lock arm 7b rotates clockwise about the 2 nd center axis J7e, and the meshing portion 7ba is released from the tooth portion of the parking lock gear 7 a. Thereby, the counter shaft 13 is freely rotatable, and the transmission mechanism 5 is in a state capable of transmitting power.

According to the present embodiment, the parking lock arm 7b extends in the up-down direction. The counter shaft 13 and the parking lock arm 7b are arranged in the vehicle front-rear direction when viewed in the axial direction. Therefore, the vertical dimension of the motor unit 10 can be suppressed. In addition, a part of the parking lock arm 7b overlaps the counter gear 23 when viewed in the axial direction. Therefore, even if the parking lock arm 7b and the counter shaft 13 are arranged in the vehicle front-rear direction, the motor unit 10 can be prevented from increasing in size in the vehicle front-rear direction.

The parking lock power transmission mechanism 7d is located between the parking lock actuator 7c and the parking lock arm 7 b. The parking lock power transmission mechanism 7d transmits power of the manual shaft 7ca rotating about the 1 st center axis J7c to the parking lock arm 7b, and rotates the parking lock arm 7b about the 2 nd center axis J7 e.

The parking lock actuator 7c has a manual shaft 7ca centered on a 1 st central axis J7c extending in the up-down direction. The parking lock actuator 7c rotates the manual shaft 7ca about the 1 st center axis J7 c. The parking lock actuator 7c drives the parking lock arm 7b via the parking lock power transmission mechanism 7 d.

The parking lock actuator 7c is fixed to the upper side of the housing 6. More specifically, the parking lock actuator 7c is located directly above the secondary axis J3. That is, the parking lock actuator 7c overlaps the sub-axis J3 as viewed in the up-down direction. This can reduce the horizontal dimension of the motor unit 10.

As shown in fig. 2, the parking lock actuator 7c is fixed to an outer side surface of the gear housing portion 63 of the housing 6. The parking lock actuator 7c is located on the gear housing 63 side with respect to the partition wall portion 61 of the housing 6. That is, according to the present embodiment, the parking lock actuator 7c does not overlap the partition wall portion 61 when viewed in the up-down direction. In order to maintain the strength of the entire housing 6, the partition wall portion 61 has a shape that protrudes radially outward of the motor axis J1 with respect to the motor 1 and the transmission mechanism 5. According to the present embodiment, since the parking lock actuator 7c and the partition wall portion 61 do not overlap each other when viewed in the vertical direction, an increase in the projection area of the motor unit 10 in the axial direction can be suppressed, and the motor unit 10 can be downsized.

As shown in fig. 1, the parking lock gear 7a is located between the counter gear 23 and the drive gear 24 in the axial direction of the counter axis J3. According to the present embodiment, the parking lock gear 7a can be disposed close to the partition wall portion 61, as compared with the case where the parking lock gear is disposed on the opposite side of the partition wall portion 61 with respect to the counter gear 23 and the drive gear 24. This can suppress the parking lock arm 7b disposed along the outer periphery of the parking lock gear 7a from being disposed to project outward in the radial direction of the sub-axis J3, thereby achieving downsizing of the motor unit 10.

(inverter unit)

As shown in fig. 2, the inverter unit 8 has an inverter 8a and an inverter case 8b that houses the inverter 8 a. Although not shown, the inverter unit 8 further includes a circuit board and a capacitor.

The inverter unit 8 has a substantially rectangular shape when viewed in the vertical direction. The inverter unit 8 is fixed to an outer side surface of the case 6. More specifically, the inverter unit 8 is fixed to the outer surface of the motor housing 62 of the case 6 in the inverter case 8 b. The inverter unit 8 is connected to a bus bar (not shown) of the motor 1 above the motor 1. The inverter unit 8 supplies an alternating current to the motor 1 via the bus bar. Thereby, the inverter unit 8 supplies electric power to the motor 1.

The inverter unit 8 is located directly above the motor 1. That is, the inverter unit 8 is located above the motor 1 and overlaps the motor 1 when viewed in the vertical direction. Thus, the dimension of the motor unit 10 in the vehicle longitudinal direction can be reduced as compared with the case where the inverter unit 8 is disposed in the vehicle longitudinal direction with respect to the motor 1. As a result, the impact region in the vehicle can be secured to be large.

Generally, the area of the motor housing 62 projected in the axial direction is smaller than the area of the gear housing 63 projected in the axial direction. According to the present embodiment, since the inverter unit 8 is disposed radially outward of the motor housing portion 62, the inverter unit 8 and the gear housing portion 63 are easily disposed to overlap each other when viewed in the axial direction. This can reduce the projection area of the entire motor unit 10 in the axial direction, and can reduce the size of the motor unit 10.

As shown in fig. 3, at least a part of the inverter unit 8 overlaps the counter gear 23 when viewed from the axial direction. By disposing the inverter unit 8 to overlap the counter gear 23, the projection area of the motor unit 10 in the axial direction can be reduced, and the motor unit 10 can be downsized.

At least a part of the inverter unit 8 overlaps the oil pump 96 when viewed from the axial direction. Likewise, at least a part of the inverter unit 8 overlaps the oil cooler 97 as viewed from the axial direction. By disposing the inverter unit 8 so as to overlap the oil pump 96 and the oil cooler 97, the projection area of the motor unit 10 in the axial direction can be reduced, and the motor unit 10 can be downsized.

Fig. 4 and 5 are exploded perspective views of the motor unit 10, and are views of separating the inverter unit 8 from the housing 6. In fig. 4 and 5, the motor unit 10 is different from each other in the perspective view direction.

As shown in fig. 4 and 5, the inverter unit 8 is fixed to the housing 6 of the motor unit 10 in the plurality of fixing

portions

40, 45. The plurality of fixing

portions

40 and 45 are classified into a 1 st fixing portion 40 (see fig. 4) and a 2 nd fixing portion 45 (see fig. 5). The 1 st fixing portion 40 is located on the vehicle front side with respect to the motor axis J1, and the 2 nd fixing portion 45 is located on the vehicle rear side with respect to the motor axis J1.

As shown in fig. 4, the 1 st fixing portion 40 includes a brim 42 provided in the inverter unit 8, an opposite surface 43 provided in the case 6, and a fixing bolt 41.

The eaves 42 of the 1 st fixing portion 40 horizontally protrudes on the outer surface of the inverter case 8b of the inverter unit 8. The brim 42 is provided with a through hole 42a penetrating in the vertical direction.

The facing surface 43 of the 1 st fixing portion 40 faces the brim 42 in the vertical direction. In the present embodiment, the facing surface 43 is provided on the case 6 located below the inverter unit 8. Therefore, in the present embodiment, the facing surface 43 of the 1 st fixing portion 40 faces upward. The facing surface 43 is provided with a screw hole 43a extending in the vertical direction and opening toward the brim 42 (i.e., the upper side).

The fixing bolt 41 of the 1 st fixing portion 40 is screwed into the screw hole 43a of the facing surface 43 through the through hole 42a of the flange 42. Thereby, the lower surface of the brim 42 and the facing surface 43 come into contact with each other, and the inverter unit 8 and the case 6 are fixed to each other.

As shown in fig. 5, the 2 nd fixing portion 45 includes a brim portion 47 provided on the case 6, an opposite surface 48 provided on the inverter unit 8, and a fixing bolt 46.

The brim 47 of the 2 nd fixing portion 45 extends horizontally on the outer surface of the motor housing 62 of the case 6. The brim 47 is provided with a through hole 47a penetrating in the vertical direction.

The facing surface 48 of the 2 nd fixing portion 45 faces the brim portion 47 in the vertical direction. In the present embodiment, the facing surface 48 is provided on the inverter unit 8 positioned above the housing 6. Therefore, in the present embodiment, the facing surface 48 of the 2 nd fixing portion 45 faces downward. The facing surface 48 is provided with a screw hole 48a extending in the vertical direction and opening toward the brim 47 (i.e., downward).

The fixing bolt 46 of the 2 nd fixing portion 45 is screwed into the screw hole 48a of the facing surface 48 through the through hole 47a of the flange 47. Thereby, the upper surface of the brim 47 and the facing surface 48 are in contact, and the inverter unit 8 and the case 6 are fixed to each other.

The 1 st fixing portion 40 and the 2 nd fixing portion 45 are disposed on opposite sides of the motor axis J1 as viewed in the vertical direction. Moreover, the

eaves

42 and 47 of the 1 st and 2

nd fixing portions

40 and 45 protrude in directions away from the motor axis J1, respectively, when viewed in the vertical direction.

According to the present embodiment, the

eaves

42 and 47 of the 1 st and 2

nd fixing portions

40 and 45, which are located on opposite sides of the motor axis J1 from each other, are provided separately in the inverter unit 8 and the case 6, respectively. Therefore, the dimension of the motor unit 10 in the vehicle longitudinal direction can be reduced as compared with a case where all the eaves are provided on either one of the inverter unit 8 and the case 6.

Fig. 6 is a schematic sectional view of the motor unit 10. In fig. 6, the detailed structure of each part (for example, the coil of the stator 32, the rotor magnet of the rotor 31, and the like) is omitted.

The inverter unit 8 has a lower surface 8s facing the case 6. The lower surface 8s is a flat surface along the horizontal direction. The lower surface 8s of the inverter unit 8 is surrounded by a plurality of fixing portions (the 1 st fixing portion 40 and the 2 nd fixing portion 45) when viewed from the vertical direction. That is, the plurality of fixing

portions

40 and 45 are arranged around the lower surface 8 s.

As shown in fig. 4 and 5, a 1 st rib 62a and a 2 nd rib 62b protruding in the radial direction of the motor axis J1 are provided on the outer surface of the motor housing 62 of the housing 6. The 1 st rib 62a extends in the axial direction of the motor axis J1. The 1 st rib 62a is located directly above the motor 1. The 2 nd rib 62b extends along the circumferential direction of the motor axis J1.

As shown in fig. 6, the 1 st rib 62a and the 2 nd rib 62b are provided with notch surfaces 62s cut along the lower surface 8s of the inverter unit 8. That is, the notch surface 62s is provided on the outer surface of the case 6. The notch face 62s is a flat face in the horizontal direction. The notch surface 62s faces the lower surface 8s of the inverter unit 8 in the vertical direction with a gap therebetween.

The surface pressure is applied to the contact surface of the case 6 and the inverter unit 8 in the 1 st fixing portion 40 and the 2 nd fixing portion 45 by the fixing

bolts

41, 46. Therefore, in the 1 st fixing portion 40 and the 2 nd fixing portion 45, the case 6 and the inverter unit 8 are integrally joined. On the other hand, in a region where the surface pressure is not applied, when the case 6 and the inverter unit 8 are in contact, the vibration of the case 6 accompanying the operation of the motor 1 and the transmission mechanism 5 is transmitted to the inverter unit 8, and the inverter unit 8 may be excited. When the inverter unit 8 is excited, there is a possibility that each part (the inverter 8a, the circuit board, the capacitor, and the like) of the inverter unit 8 is damaged. According to the present embodiment, the case 6 and the inverter unit 8 are separated in the vertical direction in the region surrounded by the fixing

portions

40, 45 when viewed in the vertical direction. This can suppress the transmission of vibration of the case 6 to the inverter unit 8 and the excitation of the inverter unit 8.

While the embodiment and the modification of the present invention have been described above, the configurations and combinations thereof in the embodiment and the modification are examples, and addition, omission, replacement, and other modifications of the configurations can be made within the scope not departing from the gist of the present invention. The present invention is not limited to the embodiments.

Description of the reference symbols

1: a motor; 5: a transfer mechanism; 6: a housing; 7: a parking lock mechanism; 7 a: a parking lock gear; 7 b: a parking lock arm; 7 c: a parking lock actuator; 8: an inverter unit; 8 a: an inverter; 8 s: a lower surface; 10: a motor unit; 11: a motor drive shaft; 13: a counter shaft; 21: a motor driving gear; 23: a counter gear; 24: a drive gear; 40: 1 st fixed part (fixed part); 45: a 2 nd fixing part (fixing part); 41. 46: fixing the bolt; 42. 47: an eave portion; 42a, 47 a: a through hole; 43. 48: opposite surfaces; 43a, 48 a: a threaded hole; 51: a ring gear; 55: an output shaft; 61: a partition wall portion; 62: a motor storage section; 62 s: a notch surface; 63: a gear housing section; 90: an oil path; 96: an oil pump; 96 m: a pump motor; 97: an oil cooler; j1: a motor axis; j3: a minor axis; j4: an output axis; j6: a rotation axis; l1: a 1 st line segment; l2: a 2 nd line segment; o: an oil; p: an oil reservoir.

Claims

1. A motor unit mounted on a vehicle to drive the vehicle, wherein:

The motor unit has:

motor;

a transmission mechanism that transmits the power of the motor and outputs it from the output shaft;

a housing that houses the motor and the transmission mechanism; and

an inverter unit that provides power to the motor,

The transfer mechanism has:

a motor drive shaft extending along the motor axis for rotation by the motor;

a motor drive gear, which is fixed to the motor drive shaft and rotates around the motor axis;

a secondary shaft extending along the secondary axis;

a countershaft gear, which is fixed to the countershaft, meshes with the motor drive gear, and rotates about the countershaft;

a drive gear, which is fixed to the secondary shaft and rotates around the secondary axis;

a ring gear meshing with the drive gear for rotation about the output axis; and

the output shaft, which is connected to the ring gear and rotates around the output axis,

the motor axis, the secondary axis and the output axis extend parallel to each other,

The motor drive shaft is a hollow shaft opened on both sides in the axial direction of the motor axis,

The output shaft passes through the inside of the motor drive shaft,

The secondary axis is positioned above the motor axis with respect to the direction of gravity,

the inverter unit is located directly above the motor,

At least a portion of the inverter unit overlaps the countershaft gear when viewed in the axial direction of the motor axis.

2. The motor unit of claim 1, wherein,

The motor unit has:

oil, which circulates in an oil circuit provided in the housing; and

an oil pump, which is provided in the path of the oil passage and pressurizes the oil,

At least a portion of the inverter unit overlaps the oil pump when viewed from the axial direction of the motor axis.

3. The motor unit of claim 1 or 2, wherein,

The motor unit has:

oil, which circulates in an oil circuit provided in the housing; and

an oil cooler provided in the path of the oil passage to cool the oil,

At least a portion of the inverter unit overlaps the oil cooler when viewed in the axial direction of the motor axis.

4. The motor unit of claim 3, wherein,

The inverter unit and the oil cooler are connected to each other by pipes constituting a refrigerant passage.

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

The inverter unit has a lower surface opposed to the housing,

The inverter unit is fixed to the casing at a plurality of fixing portions arranged around the lower surface,

A notch surface cut along the lower surface of the inverter unit is provided on the outer surface,

The cutout surface is opposed to the lower surface of the inverter unit in the vertical direction with a gap therebetween.

6. The motor unit of claim 5, wherein,

The fixed part has:

an eaves part, which is provided on one of the casing and the inverter unit and protrudes in a horizontal direction;

an opposing surface provided on the other of the housing and the inverter unit and facing the eaves in the up-down direction; and

Fixing bolts,

A through hole penetrating in the up-down direction is provided on the eaves,

A threaded hole is provided on the opposite surface,

The fixing bolt is screwed into the screw hole of the opposing surface through the through hole of the eaves portion.

7. The motor unit of claim 6, wherein,

The plurality of fixing parts are classified into a first fixing part and a second fixing part,

In the first fixing portion, the eaves portion is provided on the inverter unit, the opposing surface is provided on the housing,

In the second fixing portion, the eaves portion is provided on the housing, the opposing surface is provided on the inverter unit,

The first fixing portion and the second fixing portion are arranged on opposite sides of each other with respect to the motor axis when viewed from the up-down direction,

When viewed from the up-down direction, the eaves of the first fixing portion and the second fixing portion protrude in directions away from the motor axis, respectively.