Motor unit

Abstract

The present invention provides a motor unit, which is mounted on a vehicle to drive the vehicle, wherein the motor unit comprises: a motor having a rotor and a stator, wherein the rotor can rotate around the motor axis; a transmission mechanism, which transmits the power of the motor and outputs it from an output shaft; a housing, which has a motor housing portion for housing the motor and a gear housing portion for housing the transmission mechanism; an inverter unit, which supplies power to the motor; oil, which circulates in an oil circuit provided in the housing; and an oil cooler, which is provided in the path of the oil circuit to cool the oil, and when viewed from the axial direction of the motor axis, at least a portion of the inverter unit overlaps with the oil cooler.

Description

[0001] This application is a divisional application of the invention patent application with application number 201980062998.9 (international application number PCT / JP2019 / 037835), application date September 26, 2019, and invention name “Motor Unit”. Technical Field

[0002] The invention relates to a motor unit. Background Art

[0003] In recent years, the development of drive devices mounted on electric vehicles has been in full swing. Japanese Patent Publication No. 2010-268633 describes a motor unit connected to a PDU (power drive unit) that houses an inverter. In recent years, the development of a motor unit that integrates an inverter is underway.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication: Japanese Patent Application Publication No. 2010-268633 Summary of the invention

[0007] Problems to be solved by the invention

[0008] If the inverter and the motor unit are integrated, there is a problem that the size of the motor unit tends to increase.

[0009] One object of one embodiment of the present invention is to provide a motor unit that can be downsized by integrating an inverter.

[0010] Means for solving problems

[0011] A motor unit according to one embodiment of the present invention is mounted on a vehicle to drive the vehicle. The motor unit includes: a motor having a rotor and a stator, the rotor being rotatable around a motor axis; a transmission mechanism that transmits power of the motor and outputs it from an output shaft; a housing having a motor housing portion that houses the motor and a gear housing portion that houses the transmission mechanism; an inverter unit that supplies power to the motor; oil that circulates in an oil path provided in the housing; and an oil cooler provided in a path of the oil path to cool the oil, wherein at least a portion of the inverter unit overlaps with the oil cooler when viewed from the axial direction of the motor axis.

[0012] A motor unit according to another embodiment of the present invention is mounted on a vehicle to drive the vehicle. The motor unit includes: a motor; a transmission mechanism that transmits the power of the motor and outputs it from an output shaft; a housing that accommodates the motor and the transmission mechanism; and an inverter unit that supplies power to the motor. The transmission mechanism includes: a motor drive shaft that extends along the motor axis and is rotated by the motor; a motor drive gear that is fixed to the motor drive shaft and rotates around the motor axis; a secondary shaft that extends along the secondary axis; a secondary shaft gear that is fixed to the secondary shaft and meshes with the motor drive gear, and the secondary shaft gear rotates around the secondary axis; a drive gear that is fixed to the secondary shaft and rotates around the secondary axis; a ring gear that meshes with the drive gear and rotates around the output axis; and the output shaft that 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 that is open on both sides of the axial direction of the motor axis. The output shaft is passed through the inside of the motor drive shaft. The secondary axis is located above the motor axis relative to the gravity direction. The inverter unit is located directly above the motor. When viewed from the axial direction of the motor axis, at least a portion of the inverter unit overlaps with the secondary shaft gear.

[0013] Effects of the Invention

[0014] According to one aspect of the present invention, there is provided a motor unit that is capable of being miniaturized by integrating an inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a conceptual diagram of a motor unit according to one embodiment.

[0016] Figure 2 It is a perspective view of a motor unit according to one embodiment.

[0017] Figure 3 is a side view of a motor unit according to one embodiment.

[0018] Figure 4 It is an exploded perspective view of a motor unit according to one embodiment.

[0019] Figure 5 It is an exploded perspective view of a motor unit according to one embodiment.

[0020] Figure 6 It is a schematic cross-sectional view of the motor unit. DETAILED DESCRIPTION

[0021] Hereinafter, the motor unit of the embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical concept of the present invention. In addition, in the following drawings, in order to facilitate the understanding of each structure, the actual structure is sometimes different from the scale, quantity, etc. in each structure.

[0022] In the following description, the gravity direction is defined based on the positional relationship when the motor unit 10 is mounted on a vehicle located on a horizontal road surface. In addition, in the accompanying 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 up and down direction), the +Z direction is the upper side (the opposite side of the gravity direction), and the -Z direction is the lower side (the gravity direction). Therefore, in this specification, when it is simply referred to as the upper side, it means the upper side relative to the gravity direction. In addition, the X-axis direction is a direction perpendicular to the Z-axis direction, indicating the front and rear direction of the vehicle equipped with the motor unit 10, the +X direction is the front of the vehicle, and the -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, indicating the width direction (left and right direction) of the vehicle, the +Y direction is the left side of the vehicle, and the -Y direction is the right side of the vehicle.

[0023] Figure 1 This is a conceptual diagram of a motor unit 10 according to one embodiment. Figure 2 It is a perspective view of the motor unit 10. In addition, the motor axis J1, the auxiliary axis J3, the output axis J4, the rotation axis J6, the first center axis J7c, and the second center axis J7e described later are virtual axes that do not actually exist.

[0024] The motor unit 10 is mounted on a vehicle and drives the vehicle by rotating the wheels H. The motor unit 10 is mounted on an electric vehicle (EV), for example. In addition, the motor unit 10 can be mounted on any vehicle that uses a motor as a power source, such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHV).

[0025] like Figure 1 As shown, the motor unit 10 includes a motor 1 , a transmission mechanism (speed change axle) 5 , a housing 6 accommodating 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 .

[0026] (case)

[0027] The housing 6 is made of, for example, aluminum die casting. The housing 6 is formed by connecting a plurality of components arranged in the vehicle width direction. A storage space 6S for storing 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 storage space 6S. The storage space 6S is divided into a motor chamber 6A for storing the motor 1 and a gear chamber 6B for storing the transmission mechanism 5.

[0028] The housing 6 includes a motor housing portion 62 having a motor chamber 6A therein for housing the motor 1, a gear housing portion 63 having a gear chamber 6B therein for housing the transmission mechanism 5, and a partition wall portion 61 for dividing the motor chamber 6A and the gear chamber 6B. The partition wall portion 61 is located between the motor housing portion 62 and the gear housing portion 63 in the axial direction.

[0029] An oil reservoir P for storing oil O is provided in the lower region of the storage space 6S. A partition wall opening 61a is provided on the partition wall portion 61 that divides the motor chamber 6A and the gear chamber 6B. The partition wall opening 61a connects the motor chamber 6A and the gear chamber 6B. The oil O in the storage space 6S moves between the motor chamber 6A and the gear chamber 6B via the partition wall opening 61a.

[0030] The storage space 6S is provided with an oil passage 90 through which the oil O circulates. The oil O is supplied from the oil reservoir P to each part of the motor unit 10 in the oil passage 90. The oil passage 90 will be described in detail later.

[0031] (Oil)

[0032] The oil O is stored inside the housing. In addition, the oil O circulates in the oil passage 90 provided in the housing 6. The oil O is used to lubricate the transmission mechanism 5 and to cool the motor 1. The oil O is stored in the lower region of the storage space 6S (i.e., the oil reservoir P). In order to realize the functions of lubricating oil and cooling oil, the oil O is preferably an oil equivalent to the automatic transmission lubricating oil (ATF: Automatic Transmission Fluid) with low viscosity.

[0033] A part of the motor 1 is immersed in the oil O stored 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. Thus, the oil O cools the stator 32 .

[0034] In addition, 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 up by the movement of the ring gear 51 and diffuses 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 is spread over the tooth surface of the gear. The oil O supplied to the transmission mechanism 5 for lubrication drips and is recovered in the oil reservoir P.

[0035] (Oil circuit)

[0036] 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 for supplying the oil O from the oil reservoir P to the motor 1 and guiding the oil O to the oil reservoir P again.

[0037] In addition, in this specification, "oil path" refers to the path of the oil O that circulates in the storage space 6S. Therefore, "oil path" is a concept that includes not only a "flow path" that forms a stable flow of oil in one direction, but also a path where the oil temporarily stays (such as the oil reservoir P) and a path where the oil drips.

[0038] The oil circuit 90 is provided with an oil pump 96 and an oil cooler 97. In the oil circuit 90, the oil O circulates through the oil reservoir P, the oil pump 96, the oil cooler 97, and the motor 1 in this order, and returns to the oil reservoir P.

[0039] The oil pump 96 is provided in the oil passage 90 and pressure-feeds the oil O. The oil pump 96 is an electric pump driven by electricity. The oil pump 96 is fixed to the gear housing portion 63 of the housing 6 .

[0040] like Figure 2 As shown, the oil pump 96 is provided in the housing 6 and is housed in the oil pump housing hole 69. The oil pump housing hole 69 extends in the axial direction. The oil pump housing hole 69 opens to the left side in the vehicle width direction (+Y direction). The inner peripheral surface of the oil pump housing hole 69 opens a suction port (not shown) for sucking the oil O into the oil pump 96 and a discharge port (not shown) for pressurizing the oil O to the downstream side.

[0041] The oil pump 96 includes a pump motor 96m and a pump mechanism (not shown) driven by the pump motor 96m. The pump motor 96m is exposed outside the opening of the oil pump housing hole 69. The pump mechanism is housed inside the oil pump housing hole 69.

[0042] The rotation axis J6 of the pump motor 96m is parallel to the motor axis J1. That is, the pump motor 96m rotates around the rotation axis J6 parallel to the motor axis J1. The oil pump 96 having the pump motor 96m tends to become 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.

[0043] The pump mechanism is, for example, a trochoid pump in which an external gear and an internal gear mesh and rotate. In this case, the internal gear of the pump mechanism is rotated by the pump motor 96m. The gap between the internal gear and the external gear of the pump mechanism is connected to the suction port and the discharge port.

[0044] like Figure 1 As shown, the oil pump 96 sucks up the oil O from the oil reservoir P via a flow path provided in the housing. The oil pump 96 supplies the sucked-up oil O to the oil cooler 97 .

[0045] The oil cooler 97 is provided in the path of the oil circuit 90, and cools the oil O passing through the oil circuit 90. The oil cooler 97 is fixed to the gear storage portion 63 of the housing 6. The oil cooler 97 is connected to a refrigerant pipe 97j through which the refrigerant cooled by the radiator (not shown) passes. The oil O passing through the inside of the oil cooler 97 is cooled by heat exchange with the refrigerant passing through the refrigerant pipe 97j. In addition, the inverter unit 8 is provided in the path of the refrigerant pipe 97j. That is, the inverter unit 8 and the oil cooler 97 are connected to each other by the pipe (refrigerant pipe 97j) constituting the refrigerant path. The refrigerant passing through the refrigerant pipe 97j not only cools the oil O passing through the oil cooler 97, but also cools the inverter unit 8.

[0046] The oil O that has passed through the oil cooler 97 is supplied to the motor 1 at the upper side of the motor chamber 6A via the flow path provided in the housing 6. The oil O supplied to the motor 1 flows from the upper side to the lower side along the outer peripheral surface of the motor 1 and the coil surface of the stator 32 to remove the heat of the motor 1. Thus, the entire motor 1 can be cooled. The oil O that has cooled the motor 1 drips downward and accumulates in the lower area of ​​the motor chamber 6A. The oil O accumulated in the lower area of ​​the motor chamber 6A moves to the gear chamber 6B via the partition wall opening 61a provided in the partition wall portion 61.

[0047] (motor)

[0048] The motor 1 is a motor generator having both the function of an electric motor and the function of a generator. The motor 1 mainly functions as a motor to drive the vehicle, and functions as a generator during regeneration.

[0049] like Figure 1 As shown, the motor 1 includes a rotor 31 and a stator 32 surrounding the rotor 31. The rotor 31 is rotatable about the motor axis J1. The stator 32 is annular and surrounds the rotor 31 from the radially outer side of the motor axis J1.

[0050] The rotor 31 is fixed to a motor drive shaft 11 described later. The rotor 31 rotates around the motor axis J1. The rotor 31 includes a rotor core and a rotor magnet held on the rotor core.

[0051] The stator 32 includes a stator core and a coil. The stator core includes a plurality of teeth protruding radially inward of the motor axis J1. The coil is wound around the teeth of the stator core.

[0052] The motor 1 is connected to an inverter 8a. 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 rotation speed of the motor 1 is controlled by controlling the inverter 8a.

[0053] (Transfer Agency)

[0054] The transmission mechanism 5 transmits the power of the motor 1 and outputs it from the output shaft 55. The transmission mechanism 5 has a plurality of mechanisms built therein that are responsible for transmitting the power between the driving source and the driven device.

[0055] 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 .

[0056] Each gear and each shaft of the transmission mechanism 5 can rotate around any one of the motor axis J1, the secondary 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 secondary 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 the direction parallel to the motor axis J1 and refers to the vehicle width direction.

[0057] The motor drive shaft 11 extends along the 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. The motor drive gear 21 is fixed to the motor drive shaft 11.

[0058] The motor drive shaft 11 extends axially with the motor axis J1 as the center. The motor drive shaft 11 is a hollow shaft that is open on both axial sides of the motor axis J1. The outer shape of the motor drive shaft 11 observed along the axial direction is a cylindrical shape centered on the motor axis J1. The motor drive shaft 11 is supported by bearings so as to be rotatable around the motor axis J1. An output shaft 55 is passed through the interior of the motor drive shaft 11.

[0059] The motor driving gear 21 is fixed to the motor driving shaft 11. The motor driving gear 21 rotates together with the motor driving shaft 11 around the motor axis J1.

[0060] The secondary shaft 13 extends along the secondary axis J3. The secondary shaft 13 rotates around the secondary axis J3. The secondary shaft 13 is rotatably held on a housing (not shown) that accommodates the transmission mechanism 5, for example, via a bearing (not shown). The secondary shaft 13 has a secondary gear 23, a drive gear 24, and a parking lock gear 7a fixed thereto.

[0061] The counter gear 23 is fixed to the counter shaft 13 . The counter gear 23 rotates around the counter axis J3 together with the counter shaft 13 . The counter gear 23 meshes with the motor drive gear 21 .

[0062] The drive gear 24 is fixed to the counter shaft 13. The drive gear 24 rotates around the counter axis J3 together with the counter shaft 13 and the counter gear 23. The drive gear 24 is arranged on the opposite side of the motor 1 with respect to the counter gear 23 in the axial direction.

[0063] 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 around the counter axis J3 together with the counter shaft 13, the counter gear 23 and the drive gear 24. The parking lock gear 7a is arranged between the counter gear 23 and the drive gear 24 in the axial direction.

[0064] The ring gear 51 is fixed to the differential device 50 . The ring gear 51 rotates around 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 .

[0065] The differential device 50 is a device for transmitting torque output from the motor 1 to the vehicle wheels H. The differential device 50 has a function of transmitting the same torque to the output shafts 55 of the left and right wheels while absorbing the speed difference between the left and right wheels H when the vehicle turns.

[0066] The differential device 50 has a gear housing (not shown) fixed to the ring gear 51, a pair of pinions (not shown), a pinion shaft (not shown) and a pair of side gears (not shown). The gear housing rotates with the ring gear 51 around the output axis J4. The gear housing accommodates a pair of pinions, a pinion shaft and a pair of side gears. The pair of pinions are bevel gears opposite to each other. The pair of pinions are supported on the pinion shaft. The pair of side gears are bevel gears that mesh vertically with the pair of pinions. The pair of side gears are respectively fixed to the output shaft 55.

[0067] The output shaft 55 rotates around the output axis J4. In the motor unit 10, a pair of output shafts 55 are provided. The pair of output shafts 55 are connected to the side gear of the differential device 50 at one end, 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 each gear. In addition, the pair of output shafts 55 protrude to the outside of the housing 6 at the other end, respectively. A wheel H is installed at the other end of the output shaft 55. The output shaft 55 outputs power to the outside (to the road surface via the wheel H).

[0068] In the present embodiment, the output axis J4 is consistent with the motor axis J1. In addition, 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 miniaturized in the radial direction of the motor axis J1 compared to a motor unit having a structure in which the motor axis J1 and the output axis J4 are not coaxially arranged.

[0069] Figure 3 1 is a side view of the motor unit 10 according to one embodiment.

[0070] 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 countershaft gear 23. The countershaft gear 23 is arranged on the same axis as 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.

[0071] (Positional relationship of each axis)

[0072] like Figure 3 As shown, the secondary axis J3 is located above the motor axis J1. In addition, since the motor axis J1 is consistent with the output axis J4, the secondary axis J3 is located above the output axis J4. According to the present embodiment, when viewed from the axial direction, the centers of the secondary shaft gear 23 and the drive gear 24 are offset in the up-down direction relative to the centers of the motor 1 and the ring gear 51. Since the drive gear 24 and the ring gear 51 are meshed with each other, the absolute distance between them is uniquely determined. Therefore, by offsetting the motor axis J1 and the secondary axis J3 in the up-down direction, the dimensional components of the secondary axis J3 and the motor axis J1 in the vehicle front-to-back direction can be shortened. As a result, the dimensions of the motor unit 10 in the vehicle front-to-back direction can be miniaturized, and a larger impact area in the vehicle can be ensured.

[0073] In addition, in the present embodiment, the countershaft gear 23 and the drive gear 24 are located above the motor axis J1. That is, the lower ends of the countershaft gear 23 and the drive gear 24 are both located above the motor axis J1. Therefore, when viewed from the top and bottom directions, the drive gear 24 can be arranged to overlap the ring gear 51 to a large extent, and the size of the motor unit 10 in the vehicle front-rear direction can be further miniaturized.

[0074] like Figure 3As shown, when viewed from the axial direction, the line segment that virtually connects the motor axis J1 and the secondary axis J3 is set as the first line segment L1. The first line segment L1 forms an angle α with the plumb line VL extending in the vertical direction. The angle α is preferably within 45°. That is, the first line segment L1 preferably extends in a direction within 45° relative to the vertical direction (gravity direction). Thus, the dimension of the motor unit 10 in the vehicle front-to-back direction can be further miniaturized. In addition, the angle α is more preferably within 20°. That is, the first line segment L1 more preferably extends in a direction within 20° relative to the vertical direction. Thus, the dimension of the motor unit 10 in the vehicle front-to-back direction can be further miniaturized.

[0075] The secondary axis J3 is located at the rear side (-X direction) of the vehicle relative to the motor axis J1. As described above, a portion of the ring gear 51 is immersed in the oil O in the oil reservoir P, and the oil O is lifted up by the ring gear 51. When the vehicle moves forward, the ring gear 51 moves Figure 3 The ring gear 51 rotates in the direction of rotation T1 shown. The rotation direction T1 is the direction in which the ring gear 51 rotates upward on the rear side of the vehicle. Therefore, the oil O lifted up by the ring gear 51 is more effectively scattered on the rear side of the vehicle. According to the present embodiment, by positioning the secondary axis J3 at a position closer to the rear side of the vehicle than the motor axis J1, the oil O lifted up by the ring gear 51 can be effectively provided to the secondary shaft gear 23 and the drive gear 24. As a result, the lubricity of the tooth surfaces of the secondary shaft gear 23 and the drive gear 24 can be improved, thereby improving the power transmission efficiency of the transmission mechanism 5.

[0076] like Figure 3 As shown, 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 this embodiment, compared with the case where the oil pump and the motor axis J1 are arranged in the vehicle front-to-back direction, the size of the motor unit 10 in the vehicle front-to-back direction can be further reduced. As a result, the size of the motor unit 10 in the vehicle front-to-back direction can be reduced, and a larger collision area in the vehicle can be ensured.

[0077] The oil pump 96 is arranged on the upper side obliquely in front of the vehicle relative to the motor axis J1. That is, the oil pump 96 is located above the motor axis J1 and closer to the front side of the vehicle (+X direction) than the motor axis J1. As described above, on the upper side of the motor axis J1, the countershaft gear 23 and the drive gear 24 are located closer to the rear side of the vehicle (-X direction) than the motor axis J1. Therefore, in the present embodiment, the oil pump 96, the countershaft gear 23 and the drive gear 24 can be arranged in a staggered manner along the front-rear direction of the vehicle on the upper side of the motor axis J1. Thereby, the motor unit 10 can be miniaturized.

[0078] As described above, the oil pump 96 includes the pump motor 96m that rotates around the rotation axis J6 parallel to the motor axis J1. Figure 3 As shown, when viewed from the axial direction, the line segment that virtually connects the motor axis J1 and the rotation axis J6 is set as the second line segment L2. The second line segment L2 forms an angle β with the plumb line VL extending in the vertical direction. The angle β is preferably within 45°. That is, the second line segment L2 preferably extends in a direction within 45° relative to the vertical direction. Thus, the dimension of the motor unit 10 in the vehicle front-to-back direction can be further miniaturized. In addition, the angle β is more preferably within 35°. That is, the second line segment L2 more preferably extends in a direction within 35° relative to the vertical direction. Thus, the dimension of the motor unit 10 in the vehicle front-to-back direction can be further miniaturized.

[0079] 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 this embodiment, the size of the motor unit 10 in the vehicle front-to-back direction can be further reduced compared to the case where the oil cooler and the motor axis J1 are arranged in the vehicle front-to-back direction.

[0080] The oil cooler 97 is arranged 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 arranging the oil cooler 97 and the oil pump 96 adjacent to each other, the flow path connecting the oil cooler 97 and the oil pump 96 can be shortened. Thus, the flow path constituting the oil path 90 can be shortened, and the circulation efficiency of the oil O in the oil path 90 can be improved.

[0081] The oil cooler 97 is located at a position closer to the front side of the vehicle (+X direction) than the motor axis J1. That is, the oil cooler 97 is arranged on the upper side of the front of the vehicle relative to the motor axis J1. According to this embodiment, the oil cooler 97 can be air-cooled when the vehicle is moving forward, and the cooling efficiency of the oil cooler 97 for the oil O can be improved.

[0082] (Parking lock mechanism)

[0083] The parking lock mechanism 7 is driven in accordance with a shift operation by the driver and switches between a locked state in which the transmission of power in the transmission mechanism 5 is restricted and an unlocked state in which the restriction is released.

[0084] like Figure 3 As shown, the parking lock mechanism 7 includes 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 7d.

[0085] The parking lock gear 7a is fixed to the secondary shaft 13. The parking lock gear 7a rotates around the secondary axis J3 together with the secondary shaft 13. The parking lock gear 7a has a plurality of teeth on its outer peripheral surface that protrude radially outward from the secondary axis J3 and are arranged in the circumferential direction of the secondary axis J3.

[0086] The parking lock arm 7b is in 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 centered on a second central axis J7e extending in the axial direction. The parking lock arm 7b extends upward from the arm support shaft 7e.

[0087] The parking lock arm 7b extends along the outer peripheral surface of the parking lock gear 7a. The parking lock arm 7b is opposed to the tooth portion of the parking lock gear 7a in the radial direction of the secondary axis J3. The parking lock arm 7b has a meshing portion 7ba opposed to the tooth portion of the parking lock gear 7a. The meshing portion 7ba protrudes toward the radial inner side of the secondary axis J3. The meshing portion 7ba meshes with the tooth portion of the parking lock gear 7a. That is, the parking lock arm 7b meshes with the parking lock gear at the meshing portion 7ba.

[0088] The parking lock arm 7b is driven by the parking lock actuator 7c to rotate within a predetermined range around the second central axis J7e. When the parking lock mechanism 7 is locked by the driver's operation, Figure 3 In the process of unlocking the parking lock mechanism 7, the parking lock arm 7b rotates counterclockwise around the second center axis J7e, and the meshing portion 7ba meshes with the teeth of the parking lock gear 7a. As a result, the rotation of the secondary shaft 13 is suppressed, and the transmission of power in the transmission mechanism 5 is restricted. On the other hand, when the parking lock mechanism 7 is unlocked by the driver's operation, the parking lock arm 7b rotates clockwise around the second center axis J7e, and the meshing portion 7ba is released from the teeth of the parking lock gear 7a. As a result, the secondary shaft 13 can rotate freely, and the transmission mechanism 5 can transmit power.

[0089] According to the present embodiment, the parking lock arm 7b extends in the up-down direction. When viewed from the axial direction, the countershaft 13 and the parking lock arm 7b are arranged side by side in the vehicle front-rear direction. Therefore, the up-down dimension of the motor unit 10 can be suppressed. In addition, when viewed from the axial direction, a portion of the parking lock arm 7b overlaps with the countershaft gear 23. Therefore, even if the parking lock arm 7b and the countershaft 13 are arranged side by side in the vehicle front-rear direction, the vehicle front-rear dimension of the motor unit 10 can be suppressed from becoming larger.

[0090] The parking lock power transmission mechanism 7d is located between the parking lock actuator 7c and the parking lock arm 7b and transmits the power of the manual shaft 7ca rotating about the first center axis J7c to the parking lock arm 7b to rotate the parking lock arm 7b about the second center axis J7e.

[0091] The parking lock actuator 7c has a manual shaft 7ca centered on a first central axis J7c extending in the vertical direction. The parking lock actuator 7c rotates the manual shaft 7ca around the first central axis J7c. The parking lock actuator 7c drives the parking lock arm 7b via the parking lock power transmission mechanism 7d.

[0092] 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 secondary axis J3 when viewed from the top and bottom. This can reduce the horizontal dimension of the motor unit 10.

[0093] like Figure 2 As shown, the parking lock actuator 7c is fixed to the outer side surface of the gear housing portion 63 of the housing 6. The parking lock actuator 7c is located on the gear housing portion 63 side relative 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 with the partition wall portion 61 when viewed from the top and bottom. In order to maintain the overall strength of the housing 6, the partition wall portion 61 has a shape that protrudes radially outward from the motor axis J1 relative to the motor 1 and the transmission mechanism 5. According to the present embodiment, since the parking lock actuator 7c does not overlap with the partition wall portion 61 when viewed from the top and bottom, it is possible to suppress the increase in the axial projection area of ​​the motor unit 10, thereby achieving miniaturization of the motor unit 10.

[0094] like Figure 1 As shown, the parking lock gear 7a is located between the counter gear 23 and the drive gear 24 in the axial direction of the secondary axis J3. According to the present embodiment, compared with the case where the parking lock gear is arranged on the opposite side of the partition wall portion 61 with respect to the counter gear 23 and the drive gear 24, the parking lock gear 7a can be arranged close to the partition wall portion 61. As a result, the parking lock arm 7b arranged along the outer periphery of the parking lock gear 7a can be suppressed from being arranged to extend radially outward of the secondary axis J3, thereby achieving miniaturization of the motor unit 10.

[0095] (Inverter unit)

[0096] like Figure 2 As shown, the inverter unit 8 includes an inverter 8a and an inverter case 8b that accommodates the inverter 8a. Although not shown in the figure, the inverter unit 8 also includes a circuit board and a capacitor.

[0097] The inverter unit 8 is substantially rectangular when viewed from the top and bottom. The inverter unit 8 is fixed to the outer side of the housing 6. More specifically, the inverter unit 8 is fixed to the outer side of the motor storage portion 62 of the housing 6 in the inverter housing 8b. The inverter unit 8 is connected to a bus bar (not shown) of the motor 1 on the upper side of the motor 1. The inverter unit 8 supplies AC current to the motor 1 via the bus bar. Thus, the inverter unit 8 supplies power to the motor 1.

[0098] The inverter unit 8 is located directly above the motor 1. That is, the inverter unit 8 is located on the upper side of the motor 1 and overlaps with the motor 1 when viewed from the top and bottom. As a result, the size of the motor unit 10 in the vehicle front-to-back direction can be reduced compared to the case where the inverter unit 8 is arranged in the vehicle front-to-back direction relative to the motor 1. As a result, a larger collision area in the vehicle can be ensured.

[0099] Generally speaking, the axial projection area of ​​the motor housing portion 62 is smaller than the axial projection area of ​​the gear housing portion 63. According to the present embodiment, since the inverter unit 8 is arranged radially outside the motor housing portion 62, it is easy to overlap the inverter unit 8 and the gear housing portion 63 when viewed from the axial direction. As a result, the axial projection area of ​​the motor unit 10 as a whole can be reduced, and the motor unit 10 can be miniaturized.

[0100] like Figure 3 As shown, when viewed from the axial direction, at least a portion of the inverter unit 8 overlaps with the counter gear 23. By arranging the inverter unit 8 and the counter gear 23 to overlap, the projected area of ​​the motor unit 10 in the axial direction can be reduced, thereby achieving miniaturization of the motor unit 10.

[0101] When viewed from the axial direction, at least a portion of the inverter unit 8 overlaps with the oil pump 96. Similarly, when viewed from the axial direction, at least a portion of the inverter unit 8 overlaps with the oil cooler 97. By arranging the inverter unit 8 to overlap with the oil pump 96 and the oil cooler 97, the projected area of ​​the motor unit 10 in the axial direction can be reduced, thereby achieving miniaturization of the motor unit 10.

[0102] Figure 4 and Figure 5 1 is an exploded perspective view of the motor unit 10, and is a view in which the inverter unit 8 is separated from the housing 6. Figure 4 and Figure 5 In the figures, the perspective views of the motor units 10 are in different directions.

[0103] like Figure 4 and Figure 5 As shown, the inverter unit 8 is fixed to the housing 6 of the motor unit 10 at a plurality of fixing portions 40 and 45. The plurality of fixing portions 40 and 45 are classified into a first fixing portion 40 (see Figure 4) and the second fixing portion 45 (refer to Figure 5 ). The first fixing portion 40 is located on the vehicle front side with respect to the motor axis J1, and the second fixing portion 45 is located on the vehicle rear side with respect to the motor axis J1.

[0104] like Figure 4 As shown, the first fixing portion 40 includes a flange portion 42 provided on the inverter unit 8 , an opposing surface 43 provided on the housing 6 , and fixing bolts 41 .

[0105] The flange portion 42 of the first fixing portion 40 protrudes in the horizontal direction on the outer side surface of the inverter case 8b of the inverter unit 8. The flange portion 42 is provided with a through hole 42a penetrating in the up-down direction.

[0106] The facing surface 43 of the first fixing portion 40 faces the eaves portion 42 in the up-down direction. In the present embodiment, the facing surface 43 is provided on the housing 6 located at the lower side of the inverter unit 8. Therefore, in the present embodiment, the facing surface 43 of the first fixing portion 40 faces upward. The facing surface 43 is provided with a screw hole 43a extending in the up-down direction and opening toward the eaves portion 42 side (i.e., the upper side).

[0107] The fixing bolts 41 of the first fixing portion 40 are screwed into the screw holes 43a of the facing surface 43 via the through holes 42a of the flange portion 42. Thus, the lower surface of the flange portion 42 and the facing surface 43 come into contact, and the inverter unit 8 and the case 6 are fixed to each other.

[0108] like Figure 5 As shown, the second fixing portion 45 includes a flange portion 47 provided on the housing 6 , an opposing surface 48 provided on the inverter unit 8 , and fixing bolts 46 .

[0109] The flange portion 47 of the second fixing portion 45 protrudes in the horizontal direction on the outer side surface of the motor housing portion 62 of the housing 6. The flange portion 47 is provided with a through hole 47a penetrating in the up-down direction.

[0110] The facing surface 48 of the second fixing portion 45 faces the flange portion 47 in the up-down direction. In the present embodiment, the facing surface 48 is provided on the inverter unit 8 located on the upper side of the housing 6. Therefore, in the present embodiment, the facing surface 48 of the second fixing portion 45 faces downward. The facing surface 48 is provided with a screw hole 48a extending in the up-down direction and opening toward the flange portion 47 side (i.e., the lower side).

[0111] The fixing bolts 46 of the second fixing portion 45 are screwed into the screw holes 48a of the facing surface 48 via the through holes 47a of the flange portion 47. Thus, the upper surface of the flange portion 47 and the facing surface 48 come into contact, and the inverter unit 8 and the case 6 are fixed to each other.

[0112] When viewed from the top and bottom, the first fixing portion 40 and the second fixing portion 45 are disposed on opposite sides relative to the motor axis J1. When viewed from the top and bottom, the flange portions 42 and 47 of the first fixing portion 40 and the second fixing portion 45 extend away from the motor axis J1.

[0113] According to the present embodiment, the flange portion 42 of the first fixing portion 40 and the flange portion 47 of the second fixing portion 45, which are located on opposite sides relative to the motor axis J1, are separately provided on the inverter unit 8 and the housing 6. Therefore, compared with the case where all the flange portions are provided on either the inverter unit 8 or the housing 6, the size of the motor unit 10 in the vehicle front-rear direction can be miniaturized.

[0114] Figure 6 is a schematic cross-sectional view of the motor unit 10. Figure 6 In the figure, the detailed structure of each part (for example, the coil of the stator 32, the rotor magnet of the rotor 31, etc.) is omitted.

[0115] The inverter unit 8 has a lower surface 8s facing the housing 6. The lower surface 8s is a flat surface along the horizontal direction. When viewed from the top and bottom directions, the lower surface 8s of the inverter unit 8 is surrounded by a plurality of fixing portions (a first fixing portion 40 and a second fixing portion 45). That is, the plurality of fixing portions 40 and 45 are arranged around the lower surface 8s.

[0116] like Figure 4 and Figure 5 As shown, the first rib 62a and the second rib 62b protruding in the radial direction of the motor axis J1 are provided on the outer side surface of the motor housing portion 62 of the housing 6. The first rib 62a extends in the axial direction of the motor axis J1. The first rib 62a is located directly above the motor 1. The second rib 62b extends in the circumferential direction of the motor axis J1.

[0117] like Figure 6 As shown, the first rib 62a and the second rib 62b are provided with a notch surface 62s cut along the lower surface 8s of the inverter unit 8. That is, the notch surface 62s is provided on the outer side surface of the housing 6. The notch surface 62s is a flat surface along the horizontal direction. The notch surface 62s is opposite to the lower surface 8s of the inverter unit 8 in the vertical direction with a gap therebetween.

[0118] The fixing bolts 41 and 46 apply surface pressure to the contact surface between the housing 6 and the inverter unit 8 in the first fixing portion 40 and the second fixing portion 45. Therefore, in the first fixing portion 40 and the second fixing portion 45, the housing 6 and the inverter unit 8 are integrated. On the other hand, in the area where the surface pressure is not applied, when the housing 6 and the inverter unit 8 are in contact, the vibration of the housing 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. If the inverter unit 8 is excited, the various parts of the inverter unit 8 (inverter 8a, circuit board, capacitor, etc.) may be damaged. According to the present embodiment, in the area surrounded by the fixing portions 40 and 45 when viewed from the top and bottom directions, the housing 6 and the inverter unit 8 are separated in the top and bottom directions. As a result, it is possible to suppress the vibration of the housing 6 from being transmitted to the inverter unit 8 and exciting the inverter unit 8.

[0119] The embodiments and modifications of the present invention have been described above, but the various structures and their combinations in the embodiments and modifications are examples, and addition, omission, substitution and other changes of the structures can be made within the scope of the gist of the present invention. In addition, the present invention is not limited to the embodiments.

[0120] Description of symbols

[0121] 1: Motor; 5: Transmission mechanism; 6: Housing; 7: Parking lock mechanism; 7a: Parking lock gear; 7b: Parking lock arm; 7c: Parking lock actuator; 8: Inverter unit; 8a: Inverter; 8s: Lower surface; 10: Motor unit; 11: Motor drive shaft; 13: Countershaft; 21: Motor drive gear; 23: Countershaft gear; 24: Drive gear; 40: First fixing portion (fixing portion); 45: Second fixing portion (fixing portion); 41, 46: Fixing bolts; 42, 47 : Eaves; 42a, 47a: through holes; 43, 48: opposing surfaces; 43a, 48a: threaded holes; 51: ring gear; 55: output shaft; 61: partition wall; 62: motor housing; 62s: notch surface; 63: gear housing; 90: oil circuit; 96: oil pump; 96m: pump motor; 97: oil cooler; J1: motor axis; J3: secondary axis; J4: output axis; J6: rotation axis; L1: first line segment; L2: second line segment; O: oil; P: oil reservoir.

Claims

1. A motor unit mounted on a vehicle to drive the vehicle, wherein: The motor unit has: A motor having a rotor and a stator, wherein the rotor is rotatable about a motor axis; A transmission mechanism that transmits the power of the motor and outputs it from an output shaft; a housing having a motor housing portion for housing the motor and a gear housing portion for housing the transmission mechanism; an inverter unit that provides power to the motor; oil circulating in an oil passage provided in the housing; and an oil cooler, which is arranged in the path of the oil circuit and cools the oil, When viewed from the axial direction of the motor axis, at least a portion of the inverter unit overlaps with the oil cooler. The oil cooler is fixed to the radial outer side of the housing. The transmission mechanism includes a gear that overlaps at least a portion of the inverter unit when viewed in the axial direction of the motor axis. At least a portion of the oil cooler is disposed at a position forward of the vehicle relative to the gear.

2. A motor unit mounted on a vehicle to drive the vehicle, wherein: The motor unit has: A motor having a rotor and a stator, wherein the rotor is rotatable about a motor axis; A transmission mechanism that transmits the power of the motor and outputs it from an output shaft; a housing having a motor housing portion for housing the motor and a gear housing portion for housing the transmission mechanism; an inverter unit that provides power to the motor; oil circulating in an oil passage provided in the housing; and an oil cooler, which is arranged in the path of the oil circuit and cools the oil, When viewed from the axial direction of the motor axis, at least a portion of the inverter unit overlaps with the oil cooler. The inverter unit is fixed to the housing at a fixing portion, The fixing portion has: an eaves portion, which is provided on one of the housing and the inverter unit and extends in a horizontal direction; an opposing surface provided on the other of the housing and the inverter unit and opposed to the eaves in the up-down direction; as well as Fixing bolts, The eaves are provided with a through hole penetrating in the up-down direction. A threaded hole is provided on the opposing surface, The fixing bolt is threadably fastened to the threaded hole of the facing surface through the through hole of the eave portion.

3. The motor unit according to claim 1 or 2, wherein: The oil cooler is located above the motor axis.

4. The motor unit according to claim 1 or 2, wherein: The inverter unit and the oil cooler are connected to each other via pipes constituting a refrigerant path.

5. The motor unit according to claim 1, wherein: The inverter unit is fixed to the housing at a fixing portion, The fixing portion has: an eaves portion, which is provided on one of the housing and the inverter unit and extends in a horizontal direction; an opposing surface provided on the other of the housing and the inverter unit and opposed to the eaves in the up-down direction; as well as Fixing bolts, The eaves are provided with a through hole penetrating in the up-down direction. A threaded hole is provided on the opposing surface, The fixing bolt is threadably fastened to the threaded hole of the facing surface through the through hole of the eave portion.

6. The motor unit according to claim 2 or 5, wherein: The fixing portion includes a first fixing portion and a second fixing portion, In the first fixing portion, the eaves portion is provided on the inverter unit, and the facing surface is provided on the housing. In the second fixing portion, the eaves portion is provided on the housing, and the facing surface is provided on the inverter unit.

7. The motor unit according to claim 6, wherein: When viewed in the axial direction of the motor axis, the first fixing portion is located on the opposite side to the second fixing portion across the motor axis.

8. The motor unit according to claim 1 or 2, wherein: The inverter unit has a lower surface facing the housing, The housing and the lower surface face each other in the up-down direction with a gap therebetween.

9. The motor unit according to claim 1 or 2, wherein: The motor housing portion has a motor chamber inside. The housing has a flow path, The oil passes through the oil cooler and is then supplied to the motor at the upper side of the motor chamber via the flow path.

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