CN115136470A - Motor unit - Google Patents

Abstract

One aspect of the motor unit of the present invention includes: a motor having a rotor with a motor shaft that rotates about a motor axis and a stator located radially outward of the rotor; a first bearing that supports a motor shaft; a stator holder that holds a stator; and a housing main body that houses the motor and the stator holder. The stator holder has: a cylindrical portion surrounding the stator from a radially outer side; and a bottom plate portion extending radially inward from one axial end of the cylindrical portion. The housing main body has an opposing inner circumferential surface that radially opposes the outer circumferential surface of the cylindrical portion. A passage portion through which a refrigerant flows is provided between the outer peripheral surface and the opposing inner peripheral surface of the cylindrical portion. The bottom plate portion holds the first bearing.

Description

Motor unit

Technical Field

The present invention relates to a motor unit.

This application claims priority based on Japanese patent application No. 2020 and 026149, filed on 19/2/2020, and the contents of which are incorporated herein by reference.

Background

In recent years, a drive device mounted on an electric vehicle has been widely developed. Patent document 1 describes a motor-driven power unit (motor unit) that is miniaturized by passing an output shaft through the inside of a hollow shaft.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2009-121549

Disclosure of Invention

Technical problems to be solved by the invention

In the conventional structure, bearings that support the hollow shaft and the output shaft extending from the hollow shaft are held in a housing. Therefore, there is a problem that the structure for holding the bearing by the housing is complicated and the assembly process is complicated.

An object of one aspect of the present invention is to provide a motor unit capable of simplifying an assembly process.

Technical scheme for solving technical problem

One aspect of the motor unit of the present invention includes: a motor having a rotor with a motor shaft that rotates centering on a motor axis and a stator located radially outside the rotor; a first bearing that supports the motor shaft; a stator holder that holds the stator; and a housing main body that houses the motor and the stator holder. The stator holder has: a cylindrical portion surrounding the stator from a radially outer side; and a bottom plate portion extending radially inward from one axial end of the cylindrical portion. The housing main body has an opposing inner circumferential surface that radially opposes an outer circumferential surface of the cylindrical portion. A passage portion through which a refrigerant flows is provided between the outer peripheral surface of the cylindrical portion and the opposing inner peripheral surface. The bottom plate portion holds the first bearing.

Effects of the invention

According to an aspect of the present invention, there is provided a motor unit capable of simplifying an assembly process.

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 an exploded perspective view of a shaft holding portion of a motor unit according to an embodiment.

Fig. 4 is a schematic view of an oil pump of the motor unit of an embodiment.

Detailed Description

Hereinafter, a motor unit 10 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 following drawings, for convenience of understanding of the respective structures, scales, numbers, and the like of the respective structures may be different from those of actual structures.

Fig. 1 is a conceptual diagram of a motor unit 10. Fig. 2 is a perspective view of the motor unit 10.

In the following description, the direction of gravity is defined with reference to 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 rectangular coordinate system.

In the present embodiment, 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 this specification, the case of being simply referred to as the upper side refers to the upper side in the direction of gravity. The X-axis direction is a direction orthogonal 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 orthogonal to both the X-axis direction and the Z-axis direction, and indicates the width direction (left-right direction) of the vehicle, the + Y direction is the left direction of the vehicle, and the-Y direction is the right direction of the vehicle.

In the following description, unless otherwise specified, a direction parallel to the motor axis J1 of the motor 1 (a direction parallel to the Y axis) is simply referred to as "axial direction". In addition, the direction of the axial direction and + Y side is referred to as the other axial side, and the-Y side is referred to as the one axial side. The radial direction centered on the motor axis J1 is simply referred to as the "radial direction", and the circumferential direction centered on the motor axis J1, that is, the axial direction about the motor axis J1 is simply referred to as the "circumferential direction".

The motor axis J1 and a later-described counter axis J3 are virtual axes that do not actually exist.

The motor unit 10 is mounted to a vehicle and rotates a wheel H to advance or retreat the vehicle. The motor unit 10 is mounted on, for example, an Electric Vehicle (EV). The motor unit 10 may be mounted on a vehicle using 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 gear portion 5, an inverter 8, a housing 6 that houses the motor 1, the gear portion 5, and the inverter 8, a shaft holding portion 80 that holds a shaft in the housing 6, a stator holder 40 that holds a stator 35 of the motor 1 in the housing 6, and oil O.

(outer cover)

The housing 6 is made of, for example, aluminum die casting. The housing 6 has: a housing main body 60; a blocking member 67, the blocking member 67 being located on the other axial side (+ Y side) of the housing main body 60; an inverter cover 68, the inverter cover 68 being located on an upper side of the casing main body 60; and a bottom cover member 69, the bottom cover member 69 being positioned at a lower side of the case main body 60. That is, the motor unit 10 has the case main body 60, the blocking member 67, the inverter cover 68, and the bottom cover member 69. The housing 6 is configured by fastening the housing main body 60, the blocking member 67, the inverter cover 68, and the bottom cover member 69 to each other.

The casing body 60 is provided with a drive body housing space 61, an inverter housing space 62, and an oil reservoir space 63. An inverter housing space 62 is disposed above the drive body housing space 61, and an oil reservoir space 63 is disposed below the drive body housing space.

The drive body storage space 61 is a space in which the motor 1, the gear portion 5, the shaft holding portion 80, the stator holder 40, and the oil O are integrally connected. The inverter housing space 62 is a space for housing the inverter 8. The oil storing space 63 is a space for storing the oil O circulating in the drive body housing space 61. In this way, the housing main body 60 accommodates the motor 1, the gear portion 5, the shaft holding portion 80, the stator holder 40, the inverter 8, and the oil O in the respective spaces.

A communication hole 65 connected to the oil storage space 63 is provided in a wall surface of the lower side of the power body housing space 61. The oil O in the lower region of the driving body receiving space 61 flows into the oil storage space 63 from the communication hole 65. The oil O is accumulated in the lower region of the driving body receiving space 61 and the oil storage space 63.

The oil O circulates through an oil passage 90 provided in the housing 6. The oil O functions as lubricating oil for lubricating the gear portion 5 and also functions as cooling oil for cooling the motor 1. As the oil O, it is preferable to use the same oil as an Automatic Transmission lubricating oil (ATF) having a low viscosity.

A part of the gear portion 5, which will be described later, of the ring gear 51 is immersed in the oil O stored in the lower region of the power driver accommodating space 61. The oil O is lifted by the operation of the ring gear 51 and diffused into the drive body housing space 61. The oil O diffused into the drive body accommodating space 61 is supplied to each gear of the gear portion 5 in the drive body accommodating space 61 and spreads over the tooth surface of the gear. The oil O supplied to the gear portion 5 and used for lubrication is dropped and collected in the lower region of the drive body storage space 61.

The housing main body 60 has: a first opening 61a that exposes the drive body storage space 61 to the other axial side (+ Y side) thereof; a second opening 62a, the second opening 62a exposing the inverter housing space 62 to the upper side; and a third opening 63a exposing the oil reservoir 63 to the lower side. The first opening 61a is covered with a blocking member 67. The second opening 62a is covered by an inverter cover 68. The third opening 63a is covered by a bottom cover member 69.

The housing main body 60 has: a cylindrical portion 60a, the cylindrical portion 60a being centered on a motor axis J1; a bottom portion 60b that covers one axial side of the cylindrical portion 60 a; an expanding portion 60c that expands in the radial direction from the opening on the other axial side of the cylindrical portion 60 a; a box-shaped portion 60d, the box-shaped portion 60d being disposed above the cylindrical portion 60 a; and a storage wall portion 60e, the storage wall portion 60e being located below the cylindrical portion 60 a. The box-shaped portion 60d surrounds the inverter housing space 62. The box-shaped portion 60d has a second opening 62 a. The storage wall portion 60e surrounds the oil storage space 63. The storage wall portion 60e has a third opening 63 a.

The cylindrical portion 60a surrounds the motor 1 from the radially outer side. The bottom portion 60b is located on one axial side (-Y side) of the motor 1. The bottom portion 60b has a bearing holding portion 60ba, and the bearing holding portion 60ba holds the ball bearing 71. The bottom portion 60b supports the output shaft 55 via a ball bearing 71. Further, the bottom portion 60b supports the oil pump 96.

The expanded portion 60c axially faces the occlusion member 67. The expanded portion 60c has: a protruding portion 60ca extending from the opening of the cylindrical portion 60a along a plane orthogonal to the axial direction; and an outer edge portion 60cb, the outer edge portion 60cb extending from the extension portion 60ca toward the other axial side (+ Y side). The outer edge portion 60cb is fastened with a fastening member such as a bolt to the blocking member 67.

The blocking member 67 covers the first opening 61 a. The blocking member 67, the cylindrical portion 60a, the bottom portion 60b, and the expanded portion 60c of the housing main body 60 surround the power driver housing space 61. Therefore, by detaching the blocking member 67 from the housing main body 60, the power driver accommodating space 61 is exposed to the other side in the axial direction. The blocking member 67 has a concave shape that opens toward one axial side (Y side). The blocking member 67 supports the auxiliary shaft 13, which will be described later, via a ball bearing 79. The blocking member 67 rotatably supports the gear housing 52 and the ring gear 51, which will be described later, via a tapered roller bearing 77.

According to the present embodiment, the first opening 61a of the casing main body 60 exposes the power drive body storage space 61, which stores the motor 1, the gear portion 5, the shaft holding portion 80, and the stator holder 40, to the other side (+ Y side) in the axial direction. The motor 1, the gear portion 5, the shaft holding portion 80, and the stator holder 40 are fitted into the case main body 60 through the first opening portion 61 a.

The motor unit 10 is assembled by sequentially mounting the motor 1, the gear portion 5, and the like inside the case main body 60. In general, the posture of the housing main body 60 is changed by aligning the mounting direction of each member. However, in the case where the weight of the case main body 60 is large, the step of changing the posture of the case main body 60 may extend the working time of the assembly process.

According to the present embodiment, the motor 1, the gear portion 5, the shaft holding portion 80, and the stator holder 40 can be attached to the housing main body 60 from one direction, whereby the assembly process can be simplified, and the cost required for assembly can be reduced.

Further, according to the present embodiment, the casing main body 60 has a bottom portion 60b that closes the power driver accommodating space 61 on one side (Y side) in the axial direction of the motor 1. Therefore, the members (the output shaft 55 and the like) accommodated in the driving body accommodating space 61 from the other axial side (+ Y side) can be supported by the bottom portion 60b, so that the mounting accuracy can be improved and the mounting process can be simplified. Since the bottom portion 60b is a part of the housing main body 60, one axial side of the power driver housing space 61 is closed in advance. Therefore, as compared with the case where the drive body storage space 61 is open on both sides in the axial direction, the number of components can be reduced, and the assembly process can be simplified.

The box-shaped portion 60d has a box shape surrounding the inverter 8. The box-shaped portion 60d is open upward to form a second opening 62 a. The box-shaped portion 60d and the inverter cover 68 constitute a wall surface of the inverter housing space 62. The box-shaped portion 60d is connected to the upper side of the cylindrical portion 60 a. A part of the box-shaped portion 60d is constituted by the cylindrical portion 60a and a part of the expanded portion 60 c.

The box-shaped portion 60d has a box bottom portion (partition wall, second wall portion) 60da located between the motor 1 and the inverter 8 in the radial direction of the motor axis J1, a side wall portion 60db (partition wall, first partition wall) located between the inverter 8 and the gear portion 5 on the other axial side of the inverter 8, and the other side wall portions. The tank bottom portion 60da is a part of the cylindrical portion 60a and faces the second opening in the vertical direction. The side wall portion 60db is a part of the expanded portion 60c, and extends upward from the tank bottom portion 60 da. The case bottom portion 60da and the side wall portion 60db function as a partition wall 66 that partitions the drive body storage space 61 and the inverter storage space 62. Further, a through hole 60h is provided in the side wall portion 60 db. The through hole 60h communicates the driving object receiving space 61 with the inverter receiving space 62. As described later, the bus bar 9 passes through the through hole 60 h.

According to the present embodiment, the case main body 60 has the partition wall 66, and the partition wall 66 partitions the drive body storage space 61 and the inverter storage space 62. That is, according to the present embodiment, the member that houses the motor 1 and the gear portion 5 and the member that houses the inverter 8 are constituted by a single member (the case main body 60). Therefore, the rigidity of the entire housing main body 60 can be improved, and the vibration suppression effect can be improved. As a result, transmission of vibration caused by driving of the motor 1 and the gear portion 5 to the inverter 8 can be suppressed, and load on the inverter 8 can be suppressed.

The inverter cover 68 is fixed to the box portion 60 d. The inverter cover 68 has a top plate portion 68a extending along a horizontal plane. The inverter 8 is fixed to the back surface of the top plate portion 68a (i.e., the surface facing the inside of the inverter housing space 62). Thereby, the inverter cover 68 supports the inverter 8.

According to the present embodiment, the inverter 8 is fixed to the inverter cover 68 detachable from the case main body 60. Therefore, when the maintenance of the motor unit 10 such as the periodic inspection and the replacement of parts is performed, the inverter 8 can be easily detached from the motor unit 10 by releasing the fastening of the inverter cover 68 to the case main body 60. The above-described steps can be performed in a state where the motor unit 10 is mounted on the vehicle, and the maintainability of the inverter 8 can be improved.

Further, the top plate portion 68a may be provided with a flow path for the coolant for cooling the inverter 8. In this case, the flow path of the refrigerant is provided in the inverter cover 68 which is a different member from the case main body 60 in contact with the motor 1. According to the present embodiment, since the heat of the motor 1 is less likely to be transferred to the refrigerant, the temperature of the inverter 8 can be suppressed to be lower than the temperature of the motor. The flow path provided in the top plate portion 68a may be connected to a flow path portion (concave portion 44) described later. In this case, the refrigerant for cooling the inverter 8 can be shared with the refrigerant for cooling the motor 1.

(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. The motor 1 of the present embodiment is a three-phase ac motor.

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

The motor 1 has a rotor 31 and a stator 35 located radially outside the rotor 31. The rotor 31 is rotatable about a motor axis J1. The stator 35 is annular. The stator 35 surrounds the rotor 31 from radially outside of the motor axis J1.

The rotor 31 has a motor shaft 32, a rotor core 31a, and a rotor magnet (not shown) held by the rotor core 31 a. Namely, the motor 1 has a motor shaft 32.

The rotor 31 (i.e., the motor shaft 32, the rotor core 31a, and the rotor magnet) rotates about a motor axis J1. The torque of the rotor 31 is transmitted to the gear portion 5. The rotor core 31a is formed by laminating silicon steel plates. The rotor core 31a is a cylindrical body extending in the axial direction. A plurality of rotor magnets are fixed to the rotor core 31 a. The plurality of rotor magnets are arranged along the circumferential direction in such a manner that magnetic poles are alternated.

The motor shaft 32 extends along a motor axis J1 that extends in the width direction of the vehicle. The motor shaft 32 is a hollow shaft that opens to both sides in the axial direction of the motor axis J1. That is, the motor shaft 32 has a hollow portion 32h that opens to both sides in the axial direction.

The motor shaft 32 has: a first end portion 32A, the first end portion 32A being located on the other axial side (+ Y side); and a second end portion 32B, the second end portion 32B being located on one axial side (-Y side).

The first end portion 32A of the motor shaft 32 is rotatably supported by a ball bearing 73. A female spline 32b is provided in an opening of the hollow portion 32h of the first end portion 32A. The motor shaft 32 is connected to the input shaft 11 of the gear portion 5 at the female spline 32B of the second end portion 32B.

The second end portion 32B of the motor shaft 32 is rotatably supported by the ball bearing 72. The resolver rotor 3a is fixed to an outer peripheral surface of the second end portion 32B. The resolver rotor 3a rotates together with the motor shaft 32 about the motor axis J1. The resolver rotor 3a is located on one axial side (-Y side) of the ball bearing 72 supporting the second end portion 32B.

The stator 35 has: an annular stator core 35 a; a coil 35b, the coil 35b being wound around the stator core 35 a; and an insulator (not shown) interposed between the stator core 35a and the coil 35 b. The stator core 35a has a plurality of pole teeth projecting radially inward of the motor axis J1. Coil wires are wound around the pole teeth. The coil wire wound around the pole teeth constitutes the coil 35 b.

The coil 35b has coil side end portions 35c, and the coil side end portions 35c protrude from the stator core 35a to both axial sides. One coil side end portion 35c projects in the axial direction from the end surface on the other axial side of the stator core 35a, and the other coil side end portion 35c projects in the axial direction from the end surface on the one axial side of the stator core 35 a. The connection coil wire 35d extends from the coil side end portion 35c on the other axial side. The connection coil wire 35d includes a twisted coil wire and an insulating tube covering the outer periphery of the coil wire. The motor 1 of the present embodiment is a three-phase ac motor, and therefore has three connecting coil wires 35d corresponding to each. The connection coil line 35d is connected to the inverter 8 via the bus bar 9.

< gear part >

The gear portion 5 is connected to the other side (+ Y side) in the axial direction of the motor 1. The gear portion 5 transmits the power of the motor 1 and outputs the power from the output shaft 55. The gear portion 5 incorporates a plurality of mechanisms that transmit power between the driving source and the driven device.

The gear portion 5 has an input shaft 11, an input gear 21, a counter shaft 13, a counter gear 23, a drive gear 24, a ring gear 51, an output shaft 55, and a differential device 50.

Each gear and each shaft of the gear portion 5 are rotatable about one of the motor axis J1 and the counter shaft axis J3. In the present embodiment, the motor axis J1 and the counter shaft axis J3 extend parallel to each other. Further, the motor axis J1 and the counter shaft axis J3 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 in the present specification refers to a direction parallel to the motor axis J1, that is, the vehicle width direction.

The input shaft 11 extends along a motor axis J1. The input shaft 11 is a hollow shaft that opens to both sides in the axial direction of the motor axis J1. That is, the input shaft 11 has a hollow portion 11h opened to both sides in the axial direction.

The input shaft 11 has: a first end portion 11A, the first end portion 11A being located on the other axial side (+ Y side); and a second end portion 11B, the second end portion 11B being located on one axial side (-Y side). The input shaft 11 is rotatably supported by the ball bearing 74 between the first end portion 11A and the second end portion 11B.

A male spline 11a is provided on the outer peripheral surface of the second end 11B of the input shaft 11. The male spline 11a is fitted to the female spline 32b of the motor shaft 32. Thereby, the first end portion 32A of the motor shaft 32 and the second end portion 32B of the input shaft 11 are connected to each other. That is, the input shaft 11 is connected to the motor shaft 32 in the axial direction. Further, the hollow portion 32h of the motor shaft 32 and the hollow portion 11h of the input shaft 11 communicate with each other. The input shaft 11 is rotated by the rotation of the transmission motor 1.

The input gear 21 is provided on the outer peripheral surface of the first end portion 11A of the input shaft 11. The input gear 21 rotates with the input shaft 11 about the motor axis J1. In the present embodiment, the input gear 21 and the input shaft 11 are a single member. However, the input gear 21 may be a different member attached to the outer peripheral surface of the input shaft 11.

The countershaft 13 extends along a countershaft axis J3. The countershaft 13 rotates about a countershaft axis J3. The counter shaft 13 has: a first end portion 13A, the first end portion 13A being located on the other axial side (+ Y side); and a second end portion 13B, the second end portion 13B being located on one axial side (Y side).

The first end portion 13A of the counter shaft 13 is rotatably supported by a ball bearing 79. The second end portion 13B of the counter shaft 13 is rotatably supported by the ball bearing 78. A counter gear 23 and a drive gear 24 are provided on the outer peripheral surface of the counter shaft 13 between the first end portion 13A and the second end portion 13B in the axial direction. In the present embodiment, the drive gear 24 is located on the other axial side (+ Y side) of the counter gear.

The counter gear 23 rotates with the counter shaft 13 about a counter shaft axis J3. The counter gear 23 meshes with the input gear 21.

The drive gear 24 rotates with the countershaft 13 and the countershaft gear 23 about a countershaft axis J3.

The ring gear 51 is a gear centered on the motor axis J1. The ring gear 51 is fixed to the differential device 50. The ring gear 51 rotates about the motor axis J1. 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 50 is arranged centered on the motor axis J1. That is, the differential device 50 is disposed coaxially with the motor 1. The differential device 50 is a device for transmitting the torque output from the motor 1 to the wheels H of the vehicle. The differential device 50 has a function of absorbing a speed difference between the left and right wheels H and transmitting the same torque to the output shafts 55 of the left and right wheels when the vehicle turns.

The differential device 50 includes: a gear housing 52, the gear housing 52 being fixed to the ring gear 51; a pair of pinions 53 a; the pinion shaft 53 b; and a pair of side gears 54. The gear housing 52 rotates together with the ring gear 51 about the motor axis J1.

The gear housing 52 houses the pair of pinions 53a, the pinion shaft 53b, and the pair of side gears 54. The pair of pinions 53a are bevel gears that are coaxially disposed and face each other. The pair of pinions 53a are supported by the pinion shaft 53 b. The pair of side gears 54 are bevel gears that mesh with the pair of pinions 53a at right angles. The pair of side gears 54 are fixed to the output shaft 55.

The gear housing 52 is rotatably supported from both axial sides by tapered roller bearings 76, 77. That is, the ring gear 51 is supported by the tapered roller bearings 76 and 77 via the gear housing 52.

The output shaft 55 extends along a motor axis J1. The output shaft 55 rotates about the motor axis J1. The motor unit 10 is provided with a pair of output shafts 55 aligned in the axial direction. A pair of output shafts 55 are connected at respective one ends to the side gears 54 of the differential device 50. 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. Further, a pair of output shafts 55 project outward of the housing 6 at the respective other end portions. A wheel H is mounted on the other end of the output shaft 55. The output shaft 55 outputs power transmission to the outside (to the road surface via the wheels H).

In the present embodiment, the output shaft 55 is disposed coaxially with the motor shaft 32 and the input shaft 11. One of the pair of output shafts 55 disposed on one side in the axial direction (the (-Y side) passes through the hollow portions 32h, 11h of the motor shaft 32 and the input shaft 11. According to the motor unit 10 of the present embodiment, since the output shaft 55 is partially disposed inside the motor shaft 32 and the input shaft 11, the motor 1 and the differential device 50 can be disposed coaxially when viewed in the axial direction, and the size of the motor unit 10 in the radial direction of the motor axis J1 can be reduced.

The gear portion 5 constitutes a power transmission path from the motor 1 to the output shaft 55. The gear portion 5 has a plurality of gears (input gear 21, counter gear 23, drive gear 24, ring gear 51, pinion gear 53a, and side gear 54). The gear portion 5 transmits power from the motor shaft 32 to the output shaft 55 through the plurality of gears. In the power transmission path of the gear portion 5, the power of the motor 1 is first transmitted from the motor shaft 32 to the input shaft 11, and further transmitted from the input 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.

(stator holder)

The stator holder 40 includes: a cylindrical portion 41 surrounding the stator 35 from the radially outer side; and a bottom plate 42 extending radially inward from an end portion on one axial side (-Y side) of the cylindrical portion 41.

The stator holder 40 is disposed inside the cylindrical portion 60a of the housing main body 60. The cylindrical portion 60a of the housing main body 60 has a radially inward facing inner circumferential surface 60 aa. The opposing inner circumferential surface 60aa radially opposes the outer circumferential surface 41a of the cylindrical portion 41.

The cylindrical portion 41 is cylindrical about the motor axis J1. The outer peripheral surface of the stator 35 is fitted to the inner peripheral surface 41b of the cylindrical portion 41 to support the stator 35. Thereby, the stator holder 40 supports the stator 35.

An insertion portion 41p is provided on the inner circumferential surface 41b of the cylindrical portion 41. The fitting portion 41p is provided at the opening on the other axial side (+ Y side) of the cylindrical portion 41. The inner diameter of the fitting portion 41p is larger than the inner diameter of the region of the inner peripheral surface 41b into which the stator 35 is fitted. The first holder 81 of the shaft holding portion 80 is fitted into the fitting portion 41 p.

A recess (passage portion) 44 recessed in the radial direction is provided on the outer peripheral surface 41a of the cylindrical portion 41. The recess 44 extends over the entire circumference about the motor axis J1. The recess 44 is open radially outward. The opening of the recess 44 is covered by the opposing inner circumferential surface 60aa of the case main body 60.

The recess 44 functions as a passage portion through which the refrigerant W flows. The refrigerant W flows in the circumferential direction between the inner wall surface of the recess 44 and the opposing inner circumferential surface 60 aa. The refrigerant W cools the stator 35 via the stator holder 40. The refrigerant W is cooled by passing through a heat exchanger not shown. Therefore, the stator holder 40 and the cylindrical portion 41 of the housing main body 60 function as a water jacket that surrounds the stator 35 and cools the stator 35 by passing the refrigerant W therethrough.

In the present embodiment, a case will be described in which the recess 44 is provided on the outer peripheral surface 41a of the cylindrical portion 41, and the opening of the recess 44 is covered with the opposing inner peripheral surface 60 aa. However, a concave portion may be provided on the opposing inner circumferential surface 60aa, and an opening of the concave portion may be covered with the outer circumferential surface 41a of the cylindrical portion 41. The structure for passing the refrigerant W is not limited to the present embodiment, and a passage portion for passing the refrigerant W may be provided between the outer circumferential surface 41a of the cylindrical portion 41 and the opposing inner circumferential surface 60 aa.

A pair of fitting portions 46 that fit into the opposing inner circumferential surfaces 60aa are provided on the outer circumferential surface 41a of the cylindrical portion 41. The fitting portion 46 extends over the entire circumference around the motor axis J1. One of the pair of fitting portions 46 is located on the other axial side of the recess 44, and the other is located on one axial side of the recess 44. According to the present embodiment, the stator holder 40 is fitted to the opposing inner circumferential surface 60aa of the housing main body 60 at the fitting portion 46. This can improve the radial positional accuracy of the stator holder 40 with respect to the housing main body 60.

A pair of concave grooves 45a are provided on the outer peripheral surface 41a of the cylindrical portion 41. The groove 45a extends over the entire circumference about the motor axis J1. One of the pair of concave grooves 45a is located on the other axial side of the concave portion 44, and the other is located on one axial side of the concave portion 44. The pair of concave grooves 45a are each disposed between the pair of fitting portions 46 in the axial direction. The groove 45a is open to the radially outer side. The openings of the grooves 45a are covered by the opposing inner peripheral surfaces 60aa of the case main body 60. O-rings (seal portions) 45b are respectively housed in the pair of grooves 45 a. The O-ring 45b is compressed in the radial direction by the opposing inner peripheral surface 60 aa. Thereby, the O-ring 45b functions as a seal portion.

Further, a groove for housing an O-ring may be provided on the opposing inner circumferential surface 60aa, and the O-ring may be compressed by the outer circumferential surface 41a of the cylindrical portion 41. That is, the O-ring 45b as the seal portion may be disposed between the outer peripheral surface 41a of the cylindrical portion 41 and the opposing inner peripheral surface 60aa and extend in the circumferential direction.

According to the present embodiment, the O-rings 45b are located on both axial sides of the recess 44, which is a passage portion for the refrigerant W. The O-ring 45b prevents the refrigerant W from leaking from the recess 44 to both sides in the axial direction. Further, the oil O in the power driver housing space 61 can be prevented from entering between the pair of O-rings 45 b. This suppresses mixing of oil O with refrigerant W in recess 44.

The bottom plate portion 42 is located on one axial side (-Y side) with respect to the motor 1. The bottom plate portion 42 has a plate shape orthogonal to the motor axis J1. An insertion hole 42a is provided in the center of the bottom plate 42. The insertion hole 42a penetrates the bottom plate portion 42 in the plate thickness direction. The bottom plate portion 42 has a bearing holding portion 43, and the bearing holding portion 43 protrudes from the edge portion of the insertion hole 42a to the other axial side (+ Y side). The bottom plate portion 42 holds the ball bearing 72. Therefore, the bottom plate portion 42 can rotatably support the motor shaft 32 via the ball bearing 72.

According to the present embodiment, the stator holder 40 that supports the stator 35 supports the rotor 31 via the ball bearing 72. That is, the members interposed between the stator 35 and the rotor 31 are only the stator holder 40 and the ball bearing 72. Therefore, according to the present embodiment, the coaxiality of the rotor 31 with respect to the stator 35 can be improved by managing the size of the stator holder 40, and the driving efficiency of the motor 1 can be easily improved.

According to the present embodiment, the bottom plate portion 42 of the stator holder 40 holds the ball bearing 72. Therefore, as compared with a case where a member for holding the ball bearing 72 is separately provided, the entire motor unit 10 can be easily downsized in the axial direction. In particular, in the present embodiment, the axial position of the bearing holding portion 43 of the stator holder 40 overlaps with the axial position of the stator 35. This makes it possible to more effectively reduce the size of the motor unit 10 in the axial direction.

The output shaft 55 protrudes from an opening on one axial side (Y side) of the motor shaft 32. According to the present embodiment, the output shaft 55 and the motor shaft 32 are supported by the ball bearings 71 and 72 arranged in an axial direction. One of the ball bearings 71 and 72 is held by the housing main body 60, and the other is held by the stator holder 40. According to the present embodiment, as compared with the case where both the ball bearings 71 and 72 are held by the housing main body 60, the structure of the housing main body 60 can be simplified, and the assembly process as a whole can be simplified.

According to the present embodiment, the ball bearing 72 is disposed radially inward of one coil side end portion 35c located on one axial side of the pair of coil side end portions 35c of the stator 35. More specifically, the axial position of the ball bearing 72 overlaps with the axial position of the one coil side end portion 35c located on the one axial side. Therefore, the ball bearing 72 that supports the second end portion 32B of the motor shaft 32 can be disposed at a position closer to the first end portion 32A. Thus, the bearings 72 and 73 supporting both end portions of the motor shaft 32 can be disposed close to each other, and eccentricity and the like of the motor shaft 32 can be suppressed. Further, the oil O dropped from the coil side end 35c by cooling the coil side end 35c can be supplied to the ball bearing 72, and the lubricity of the ball bearing 72 can be improved.

The bottom plate portion 42 of the stator holder 40 supports the resolver stator 3b in addition to the ball bearing 72. The resolver stator 3b is disposed inside the insertion hole 42a and on one axial side of the ball bearing 72. The resolver stator 3B surrounds the second end portion 32B of the motor shaft 32 from the radially outer side. The resolver stator 3b is radially opposed to the resolver rotor 3 a.

The resolver stator 3b and the resolver rotor 3a constitute a resolver. Namely, the motor unit 10 includes the resolver 3. The resolver 3 measures the rotational speed of the motor shaft 32. The resolver 3 is disposed between the ball bearings 71 and 72 in the axial direction.

According to the present embodiment, since the bottom plate portion 42 of the stator holder 40 supports the resolver stator 3b, the resolver stator 3b can be disposed closer to the center of the axial dimension of the motor 1 than the case where the housing body 60 supports the resolver stator 3 b. This can suppress the resolver stator 3b from protruding in the axial direction with respect to the motor 1, and can reduce the axial dimension of the motor unit 10.

(shaft holding part)

The shaft holding portion 80 is disposed in the power driver accommodating space 61. Further, the shaft holding portion 80 is located between the motor 1 and the gear portion 5. The shaft holding portion 80 has a first holder 81, a second holder 86, ball bearings 73, 74, 75, 78, and a tapered roller bearing 76.

The first holder 81 is fixed to the stator holder 40 from the other axial side (+ Y side). Further, the second holder 86 is fixed to the first holder 81 from the other axial side (+ Y side). The ball bearings 73, 74, 78 are held by the first holder 81. Further, the ball bearing 75 and the tapered roller bearing 76 are held by a second holder 86.

Fig. 3 is an exploded perspective view of the shaft holding portion 80.

The first holder 81 includes a main body disc portion 82 and a protruding disc portion 83. The main body disc portion 82 and the protruding disc portion 83 are a single member connected to each other. The outer diameter of the main body disk portion 82 is larger than the outer diameter of the protruding disk portion 83. The protruding disk portion 83 is arranged offset from the main body disk portion 82 in the other axial direction (+ Y side).

The main body disk portion 82 is disk-shaped about the motor axis J1. A first insertion hole 82h is provided in the center of the main body disk 82 to penetrate in the axial direction. The first insertion hole 82h has a circular shape centered on the motor axis J1 as viewed in the axial direction. The first end portion 32A of the motor shaft 32, the second end portion 11B of the input shaft 11, and the output shaft 55 are disposed inside the first insertion hole 82 h.

A plurality of screw holes 82s are provided in the other axial side (+ Y side) surface of the main body disk portion 82. The plurality of threaded holes 82s are arranged along the circumferential direction of the motor axis J1 so as to surround the first insertion hole 82 h. A fixing screw 84 for fixing the second holder 86 is inserted into the screw hole 82 s. That is, the second holder 86 is fixed by a plurality of fixing screws 84 inserted toward one axial side (Y side) with respect to the first holder 81. Thus, the second holder 86 can be attached to the first holder 81 from the first opening 61a side in the power driver housing space 61, and therefore, the assembly process of the motor unit 10 can be simplified. Also, the plurality of set screws 84 are arranged along the circumferential direction of the motor axis J1. Therefore, the second holder 86 can be firmly fixed around the motor axis J1.

The projecting disk portion 83 is disk-shaped about the auxiliary shaft axis J3. A second insertion hole 83h penetrating in the axial direction is provided in the center of the protruding disk portion 83. The second end 13B of the counter shaft 13 is disposed inside the second insertion hole 83 h.

As shown in fig. 1, the main body disk portion 82 has an outer edge protruding portion 82c, and the outer edge protruding portion 82c protrudes from the outer edge of the main body disk portion 82 to one axial direction side (-Y side). The outer edge protrusion 82c is cylindrical about the motor axis J1. The outer peripheral surface of the outer edge projection 82c is fitted into the fitting portion 41p of the stator holder 40. Thereby, the first holder 81 is supported by the stator holder 40. Further, the first holder 81 is fixed to the housing main body 60 via the stator holder 40.

The main body disk 82 includes two bearing holding portions 82a and 82 b. The bearing holding portions 82a, 82b are provided on the outer edge of the first insertion hole 82 h.

The bearing holding portion 82a is provided on the surface of the main body disk portion 82 facing one axial side (-Y side). The bearing holding portion 82a holds the ball bearing 73. Thereby, the bearing holding portion 82A rotatably supports the first end portion 32A of the motor shaft 32 via the ball bearing 73. The ball bearing 73 is located between the motor 1 and the gear portion 5 in the axial direction. Therefore, the shaft holding portion 80 rotatably supports the motor shaft 32 on the other axial side of the motor 1.

In the present embodiment, the motor 1 and the gear portion 5 are housed in the drive body housing space 61 integrally connected. Therefore, in the case where the shaft holding portion 80 is not provided, the motor shaft 32 becomes a cantilever support, and the eccentricity accompanying the rotation may become significant. According to the present embodiment, the shaft holding portion 80 rotatably holds the motor shaft 32 between the motor 1 and the gear portion 5. Therefore, the shaft holding portion 80 can support the motor shaft 32 on both sides of the motor 1 together with the ball bearing 72 that supports the second end portion 32B. According to the present embodiment, the eccentricity of the motor shaft 32 is suppressed, and the rotation efficiency of the motor shaft 32 is improved.

The bearing holding portion 82b is provided on the surface of the main body disk portion 82 facing the other axial side (+ Y side). The bearing holding portion 82b holds the ball bearing 74. Thereby, the bearing holding portion 82b rotatably supports the input shaft 11 via the ball bearing 74.

The protruding disk portion 83 has a bearing holding portion 83 a. The bearing holding portion 83a is provided on the outer edge of the second insertion hole 83 h. The bearing holding portion 83a is provided on the surface of the protruding disk portion 83 facing the other axial side (+ Y side). The bearing holding portion 83a supports the ball bearing 78. The bearing holding portion 83a rotatably supports the counter shaft 13 via the ball bearing 78.

According to the present embodiment, the first holder 81 rotatably supports not only the shaft on the motor axis J1 (the motor shaft 32 and the input shaft 11) but also the shaft on the counter shaft axis J3 (the counter shaft 13). Therefore, by managing the machining accuracy of the first holder 81, the distance dimension between the motor axis J1 and the counter shaft axis J3 can be secured, and as a result, the power transmission efficiency between the gears can be improved. Further, the assembly process can be simplified by attaching the first holder 81 to the housing main body 60 in a state where the plurality of bearings (ball bearings 73, 78) are incorporated.

The axial positions of the ball bearings 73 and 78 may overlap each other. The axial positions of the ball bearings 74 and 78 may overlap each other. That is, it is preferable that the axial positions of the plurality of bearings of the shaft holding portion 80 overlap each other. Accordingly, as compared with the case where the bearings are arranged in a staggered manner, the axial dimension of the shaft holding portion 80 can be reduced, and the drive body housing space 61 can be effectively utilized. Further, among the plurality of bearings which are overlapped in the axial direction position, the oil O scattered in the radial direction can be supplied from one bearing to the other bearing, and the lubricity of the bearing can be improved.

As shown in fig. 3, the second holder 86 has an enclosing portion 88 and a flange portion 89. The surrounding portion 88 and the flange portion 89 are a single member connected to each other.

The surrounding portion 88 is annular to surround the motor axis J1 from the radially outer side. The surrounding portion 88 has: a disc portion 88 a; and a surrounding cylindrical portion 88b, the surrounding cylindrical portion 88b extending from an outer edge of the disc portion 88a toward one axial side.

The disk portion 88a has a disk shape centered on the motor axis J1. A third insertion hole 88h is provided in the center of the disk portion 88a so as to penetrate in the axial direction. The third insertion hole 88h has a circular shape centered on the motor axis J1 when viewed in the axial direction. The output shaft 55 is disposed inside the third insertion hole 88 h.

The disk portion 88a has two bearing holding portions 88e and 88 f. The bearing holding portions 88e and 88f are provided on the outer edge of the third insertion hole 88 h.

The surrounding cylindrical portion 88b has a cylindrical shape centered on the motor axis J1. The surrounding cylinder portion 88b is open to one axial side (-Y side). The surrounding tube portion 88b is provided with a notch portion 88 c. The notch 88c extends from an end portion surrounding one axial side (-Y side) of the cylindrical portion 88b to the other axial side (+ Y side). The notch 88c is provided in an upper region of the entire circumference surrounding the tube portion 88 b.

The second holder 86 is fixed to the first holder 81 so as to close one axial side (-Y side) of the notch portion 88c by the first holder 81. Thus, the notch 88c functions as an opening 87 that exposes the inside of the surrounding portion 88 upward.

The flange portion 89 is located at one axial end portion (-Y side) of the surrounding portion 88. More specifically, the flange portion 89 extends radially outward from one axial end surrounding the cylindrical portion 88 b. The flange portion 89 is provided with a plurality of through holes 89a penetrating in the axial direction. The plurality of through holes 89a are arranged along the circumferential direction of the motor axis J1. In order to fix the second holder 86 to the first holder 81, a fixing screw 84 inserted into the screw hole 82s of the first holder 81 is inserted into the through hole 89 a. Thereby, the second holder 86 is supported by the first holder 81.

As shown in fig. 1, the bearing holding portion 88f of the second holder 86 is provided on the surface of the disk portion 88a facing one axial side (-Y side). The bearing holding portion 88f holds the ball bearing 75. Thereby, the bearing holding portion 88f rotatably supports the output shaft 55 via the ball bearing 75.

The bearing holding portion 88e is provided on the surface of the main body disk portion 82 facing the other axial side (+ Y side). The bearing holding portion 88e holds the tapered roller bearing 76. Thereby, the bearing holding portion 88e rotatably supports the gear housing 52 and the ring gear 51 via the tapered roller bearing 76.

According to the present embodiment, the second holder 86 that supports the output shaft 55 via the ball bearing 75 is fixed to the first holder 81. The first holder 81 supports the motor shaft 32 and the input shaft 11 via the ball bearings 73, 74. Therefore, according to the present embodiment, the coaxiality of the output shaft 55 with respect to the motor shaft 32 and the input shaft 11 can be ensured in accordance with the mounting accuracy of the second holder 86 with respect to the first holder 81. Therefore, it is easy to improve the rotation efficiency of the motor shaft 32 and the input shaft 11.

According to the present embodiment, the shaft holding portion 80 has the surrounding portion 88 surrounding the motor axis, and the surrounding portion 88 is provided with the opening 87 that opens in the radial direction along the motor axis J1. The opening 87 communicates the inside and outside of the surrounding portion 88. This allows the oil O scattered into the drive body housing space 61 by the lifting of the ring gear 51 to reach the surrounding portion 88, and the scattered oil O can be supplied to the inside of the surrounding portion 88. The opening 87 of the present embodiment exposes the ball bearings 74 and 75 to the inside of the power driver housing space 61. Therefore, according to the present embodiment, the oil O can be supplied from the opening 87 to the ball bearings 74 and 75, and the lubricity of the ball bearings 74 and 75 can be improved.

In the present embodiment, the opening 87 opens upward. Therefore, the oil O reaching the inside of the surrounding portion 88 from the opening 87 can be accumulated inside the surrounding portion 88. That is, the surrounding portion 88 has the oil accommodating space 64 in which the oil O is stored. The opening 87 and the oil accommodating space 64 are disposed in the second holder 86.

The surrounding portion 88 of the shaft holding portion 80 of the present embodiment surrounds the first end portion 11A of the input shaft 11. Therefore, the hollow portion 11h of the input shaft 11 opens into the oil accommodating space 64. Part of the oil O in the oil accommodating space 64 enters the hollow portion 11h, and the lubricity between the inner peripheral surface of the input shaft 11 and the output shaft 55 can be improved. Also, the oil O is supplied to the male spline 11a and the female spline 32b of the connection portion of the input shaft 11 and the motor shaft 32, thereby suppressing abrasion of the connection portion. The oil O is scattered from the connecting portion between the male spline 11a and the female spline 32b, and is supplied to the ball bearing 73 that supports the motor shaft 32, thereby improving the lubricity of the ball bearing 73.

In the present embodiment, at least a part of the input gear 21 provided at the first end portion 11A of the input shaft 11 is located in the oil accommodating space 64. Therefore, the lower end portion of the input gear 21 is immersed in the oil O accumulated in the oil accommodating space 64. The oil O is raised by the operation of the input gear 21, spreads into the power driver housing space 61, and spreads over the tooth surfaces of the gears.

In the present embodiment, the meshing portion 14 where the input gear 21 and the counter gear 23 mesh with each other is disposed in the opening 87. Therefore, the shaft holding portion 80 can support the shaft on both sides of the input gear 21 in the axial direction, and can transmit power from the input gear 21 to the counter gear 23.

According to the present embodiment, the shaft holding portion 80 includes a plurality of bearing holding portions 82a, 82b, 88f, 88e, and 83a that hold the bearings, respectively. The bearing holding portions 82a, 82b, 83a are disposed in the first holder 81, and the bearing holding portions 88f, 88e are disposed in the second holder 86. Since the first holder 81 and the second holder 86, which can be separated from each other, each have a bearing holding portion, the first holder 81 and the second holder 86 can be mounted in a separated state, and the assembly process can be simplified. Further, the bearings can be mounted from both sides in the axial direction of the first holder 81 and the second holder 86, respectively, so that the positional accuracy in the axial direction and the radial direction of each bearing can be improved.

(inverter)

As shown in fig. 1, the inverter 8 is disposed in the inverter housing space 62. The inverter 8 is fixed to the inverter cover 68. The inverter 8 is connected to a stator 35 of the motor 1 via a bus 9. The inverter 8 converts the direct current into an alternating current and supplies the alternating current to the motor 1. That is, the inverter 8 controls the current supplied to the motor 1.

The inverter 8 is disposed on the outer peripheral surface side of the motor 1. More specifically, the inverter 8 is located directly above the motor 1. This can reduce the size of the motor unit 10 in the front-rear 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 8 is disposed in the vehicle longitudinal direction with respect to the motor 1. As a result, a collision absorption region in the vehicle can be secured significantly (Japanese: クラッシャブルゾーン).

At least a part of the inverter 8 overlaps the counter gear 23 when viewed from the axial direction. By disposing the inverter 8 so as to overlap the counter gear 23, the projected area of the motor unit 10 in the axial direction is reduced, and the motor unit 10 can be downsized.

The bus bar 9 is made of a conductive metal material. The bus bar 9 electrically connects the motor 1 and the inverter 8 together. Since the motor 1 of the present embodiment is a three-phase ac motor, the motor unit 10 includes three inverters 8 corresponding to each motor.

In the bus 9, the bus 9 includes: an axially extending portion 9a, the axially extending portion 9a extending in an axial direction; and a radially extending portion 9b, the radially extending portion 9b extending in a radial direction of the motor axis J1.

An end portion on one axial side (-Y side) of the axially extending portion 9a is connected to the inverter 8. Further, an end portion of the other axial side (+ Y side) of the axially extending portion 9a is connected to the radially extending portion 9 b. The radially extending portion 9b extends radially inward from an end of the axially extending portion, and is connected to the connecting coil wire 35d at a tip thereof. That is, the bus bar 9 is connected to the inverter 8 at the axially extending portion 9a, and is connected to the connecting coil wire 35d at the radially extending portion 9 b.

The axially extending portion 9a passes through a through hole 60h provided in a partition wall 66 that divides the drive body storage space 61 and the inverter storage space 62. Thereby, the bus bar 9 is disposed across the power driver housing space 61 and the inverter housing space 62.

The bus bar 9 is held by a bus bar holder, not shown. The bus bar holder has a seal structure that is disposed between the inner peripheral surface of the through hole 60h and the bus bar 9 and seals between the drive body storage space 61 and the inverter storage space 62. Thereby, the bus bar holder suppresses the oil O in the power driver housing space 61 from entering the inverter housing space 62.

According to the present embodiment, the through-hole 60h through which the bus bar 9 passes is provided to the side wall portion 60 db. The side wall portion 60db is located on the other axial side of the inverter 8 between the inverter 8 and the gear portion 5. Further, the through hole 60h penetrates the side wall portion 60db in the axial direction, and the drive body receiving space 61 is opened to the other side (+ Y side) in the axial direction at the first opening portion 61a as described above, so that the assembly worker can mount the bus bar 9 to the case main body 60 by receiving the bus bar 9 in the drive body receiving space 61 from the first opening portion 61a and inserting the bus bar into the through hole 60 h. According to the present embodiment, the bus bar 9 can be attached to the housing main body 60 from the first opening 61a in the same manner as other members, and the assembly process can be simplified by attaching from one direction.

< oil passage >

The oil passage 90 is a path of oil O for circulating the oil O in the casing 6. The oil passage 90 is provided in the housing 6. An oil pump 96 is provided in the oil passage 90.

In the present specification, the concept of the "oil passage" includes not only a "flow passage" that forms a stable oil flow always in one direction, but also a path (for example, the oil storage space 63) in which the oil supply temporarily stays and a path in which the oil supply drops.

The oil passage 90 includes: a first flow path 91 that leads the oil O from the oil storage space 63 to the oil pump 96; and a second flow path 97 extending from the oil pump 96 toward the upper side of the motor 1 and supplying the oil O to the motor 1. The oil O reaches the oil pump 96 from the oil storage space 63 via the first flow path 91, and is supplied from the oil pump 96 to the motor 1 via the second flow path 97. Further, the oil O drips from the motor 1 and returns to the oil storage space 63.

The first flow path 91 and the second flow path 97 are provided inside the wall surface of the casing main body 60. The first flow path 91 communicates from the oil reservoir 63 to the oil pump 96. On the other hand, the second flow path 97 branches off from the oil pump 96 to extend upward and opens above the pair of coil side end portions 35c of the stator 35.

The oil pump 96 is located on one axial side (-Y side) of the motor 1. The oil pump 96 is a mechanical pump that is connected to the output shaft 55 and driven by rotation of the output shaft 55. The oil pump 96 sucks up the oil O from the oil storage space 63 and pressure-feeds the oil O into the oil passage 90.

Fig. 4 is a schematic view of the oil pump 96 as viewed from the axial direction.

The oil pump 96 has a pump housing 96a, an external gear 92, and an internal gear 93.

The pump housing 96a is fixed to the bottom 60b of the housing body 60. In the present embodiment, the pump housing 96a is circular when viewed from the axial direction. Pump casing 96a is provided with pump chamber 96c, suction port 94, and discharge port 95.

Pump chamber 96c is circular when viewed axially about an axis J2 that is eccentric with respect to motor axis J1. Suction port 94 and discharge port 95 are connected to pump chamber 96 c. The external gear 92 and the internal gear 93 are disposed in the pump chamber 96 c.

Suction port 94 and discharge port 95 are open on the side surface of pump chamber 96c facing one axial direction side. The suction port 94 is connected to the first flow path 91. The discharge port 95 is connected to the second flow path 97. The oil pump 96 sucks the oil O from the suction port 94 and discharges the oil O from the discharge port 95.

The external gear 92 is a gear rotatable about the motor axis J1. The external gear 92 is fixed to the output shaft 55. The external gear 92 is housed in the pump chamber 96 c. The external gear 92 has a plurality of teeth 92a on the outer peripheral surface. The tooth profile of the tooth 92a of the external gear 92 is a trochoid tooth profile.

The internal gear 93 is an annular gear rotatable about an axis J2 eccentric to the motor axis J1. The outer diameter of the internal gear is slightly smaller than the inner diameter of pump chamber 96 c. The outer peripheral surface of the internal gear 93 slidably faces the inner peripheral surface of the pump chamber 96 c.

The internal gear 93 surrounds the outer gear 92 in the radial direction, and meshes with the outer gear 92. The internal gear 93 has a plurality of tooth portions 93a on an inner peripheral surface. The tooth profile of the tooth 93a of the internal gear 93 is a trochoid tooth profile.

The external gear 92 is rotated about the motor axis J1, so that the external gear 92 and the internal gear 93 meshing with the external gear 92 are also rotated about the axis J2. Thereby, the gap between the tooth portion 92a of the external gear 92 and the tooth portion 93a of the internal gear 93 moves in the circumferential direction, and the oil pump 96 transfers the oil O in the gap from the suction port 94 to the discharge port 95. Thereby, the oil pump 96 sucks the oil O from the suction port 94 and discharges the oil O from the discharge port 95.

The oil O discharged from the oil pump 96 is supplied to the pair of coil side end portions 35c through the second flow passages 97, respectively. The oil O supplied to the coil side end portion 35c permeates the entire coil 35b by the capillary force and the gravity acting between the coil wires while depriving heat from the stator 35. Then, the oil O drips downward and returns to the oil reservoir 63 through a hole provided in the stator holder 40, the communication hole 65, and the like.

According to the present embodiment, the stator core 35a is cooled by the refrigerant W via the stator holder 40, and the coil side end 35c is directly cooled by the oil O, so that each part of the stator 35 can be efficiently cooled.

In the present embodiment, the oil O is stored in the oil storage space 63. A motor 1 is disposed directly above the oil reservoir space 63, and a passage portion (recess 44) for the refrigerant W is provided around the motor 1. Therefore, the oil O of the oil storage space 63 is cooled by the refrigerant W. Therefore, the oil O is supplied to the coil side end portion 35c in a state where the temperature has decreased, and the coil side end portion 35c can be efficiently cooled.

(method of manufacturing Motor Unit)

Next, a procedure of mounting each member to the housing main body 60 will be described as a method of manufacturing the motor unit 10, based on fig. 1.

The method of manufacturing the motor unit 10 mainly includes the following first to ninth steps.

< first step >

The first step is an output shaft mounting step of mounting the output shaft 55 to the housing main body 60. Prior to the first process, the bottom cover member 69 is previously mounted to the case main body 60. Thereby, the bottom cover member 69 covers the third opening 63a of the housing main body 60.

In the first step, first, a seal member and a ball bearing 71, not shown, are attached to the bearing holding portion 60ba provided at the bottom portion 60b of the housing main body 60. Next, the output shaft 55 is received in the power driver receiving space 61 from the first opening 61a of the case main body 60. Next, the output shaft 55 is attached to the housing main body 60 by inserting the end portion on one axial side (the (-Y side) of the output shaft 55 into the ball bearing 71. Next, the oil pump 96 is attached to the output shaft 55.

< second step >

The second step is a motor mounting step of mounting the motor 1 to the housing main body 60. Before the second step, the rotor 31 and the stator 35 are assembled in advance. The stator 35 is mounted in advance on the stator holder 40 together with the ball bearing 72.

In the second step, first, the stator 35 and the stator holder 40 assembled in advance are accommodated in the power driver accommodating space 61 through the first opening 61 a. The fitting portion 46 of the stator holder 40 is fitted into the opposing inner circumferential surface 60aa of the cylindrical portion 60a of the housing main body 60. Thereby, the stator holder 40 and the stator 35 are fixed to the housing main body 60.

In the second step, the output shaft 55 is inserted into the hollow portion 32h of the motor shaft 32, and the rotor 31 is accommodated in the power driver accommodating space 61 through the first opening 61 a.

Through the above steps, in the second step, the motor 1 and the stator holder 40 are accommodated and fixed in the power driver accommodating space 61 from the first opening 61a of the housing main body 60.

< third Process step >

The third step is a bus bar mounting step of mounting the bus bar 9 to the housing main body 60. In the third step, the three bus bars 9 are accommodated in the power driver accommodating space 61 from the first opening 61a of the case main body 60, and are fixed to the case main body 60 through the through holes 60h of the case main body 60. Next, the bus bar 9 is connected to the connecting coil line 35d extending from the stator 35.

< fourth step >

The fourth step is a step of attaching the first holder 81 to the stator holder 40. Prior to the fourth process, the ball bearings 73 and 78 are mounted in advance on the first holder 81.

In the fourth step, first, the first holder 81 is accommodated in the power driver accommodating space 61 from the first opening 61a of the housing main body 60, and the motor shaft 32 is inserted into the ball bearing 73. The outer edge projection 82c of the first holder 81 is fitted into the fitting portion 41p of the stator holder 40, and the first holder 81 is fixed to the housing main body 60 via the stator holder 40. Next, the ball bearing 74 is attached to the first holder 81.

< fifth Process step >

The fifth step is a step of attaching the input shaft 11, the counter shaft 13, the input gear 21, the counter gear 23, and the drive gear 24 to the housing main body 60. In the fifth step, the input shaft 11, the counter shaft 13, the input gear 21, the counter gear 23, and the drive gear 24 are accommodated in the power driver accommodating space 61 from the first opening 61a of the housing main body 60 and attached.

< sixth Process step >

The sixth step is a step of attaching the second holder 86 to the first holder 81. Before the sixth step, the ball bearing 75 and the tapered roller bearing 76 are mounted in advance on the second holder 86.

In the sixth step, first, the second holder 86 is accommodated in the power driver accommodating space 61 from the first opening 61a of the housing main body 60, and the output shaft 55 is inserted into the ball bearing 75. Then, the second holder 86 is fixed to the first holder 81.

Through the mounting steps of the first holder 81 and the second holder 86 in the fourth step and the sixth step, the shaft holding portion 80 is received and fixed in the driving body receiving space 61 from the first opening portion 61a of the housing main body 60.

< seventh Process step >

The seventh step is a step of attaching the ring gear 51 and the differential device 50 to the shaft holding portion 80. Before the seventh step, the differential unit 50 is assembled in advance, and the ring gear 51 is attached to the gear housing 52 of the differential unit 50.

In the seventh step, the gear housing 52 is held by the tapered roller bearing 76, and the output shaft 55 is connected to the side gear 54 of the differential device 50.

The fifth step and the seventh step are gear part mounting steps of storing and fixing the gear part 5 in the drive storage space 61 from the first opening 61 a.

< eighth Process step >

The eighth step is a step of attaching the blocking member 67 to the case main body 60. Prior to the eighth step, the ball bearing 79 and the tapered roller bearing 77 are assembled in advance in the blocking member 67.

In the eighth step, first, the first opening 61a of the case main body 60 is attached and fastened so as to be covered by the blocking member 67. At the same time, the counter shaft 13 is inserted into the ball bearing 79, and the gear housing 52 is held by the tapered roller bearing 77.

The first to eighth steps are steps of attaching the respective members including the motor 1 and the gear portion 5 to the drive body accommodating space 61 of the casing main body 60. In the first to eighth steps, each member is attached to the housing main body 60 from the other axial side (+ Y side). According to the present embodiment, the first to eighth steps can be performed without changing the posture of the case main body 60, and as a result, the time required for manufacturing the motor unit 10 can be shortened.

< ninth step >

The ninth step is a step of attaching the inverter 8 to the case main body 60. Prior to the ninth process, the inverter 8 is mounted in advance to the inverter cover 68. That is, the step of mounting the inverter 8 includes a preliminary step of fixing the inverter 8 to the inverter cover 68.

In the ninth step, the inverter cover 68 to which the inverter 8 is attached is fixed to the case main body 60. Thereby, the inverter 8 is disposed in the inverter housing space 62, and the second opening 62a of the case main body 60 is covered by the inverter cover 68. Next, a window portion (not shown) disposed on the upper surface of the inverter cover is opened, the bus bar 9 is connected to the inverter 8 in the inverter housing space 62, and the window portion is closed again.

As described above, in the first to eighth steps, the respective members are attached to the case main body 60 from the opening direction of the first opening portion 61 a. On the other hand, in the ninth step, the inverter 8 and the inverter cover 68 are attached to the case main body 60 from the opening direction of the second opening 62 a. Therefore, the assembly posture of the housing main body 60 is changed before the ninth process is performed. In the present embodiment, the steps (first step to eighth step) of attaching the motor 1 and the gear portion 5 are performed in a state where the first opening portion is directed upward. The step of mounting the inverter 8 (ninth step) is performed with the second opening 62a facing upward. This makes it possible to facilitate the assembly operation.

While the embodiment of the present invention and the modified examples thereof have been described above, the configurations and combinations thereof in the embodiment and the modified examples are examples, and additions, omissions, substitutions, and other changes in the configurations can be made without departing from the spirit of the present invention. The present invention is not limited to the embodiments.

(symbol description)

1, a motor; 3, a resolver; 3a resolver rotor; 3b a resolver stator; 5a gear portion; 6, a shell; 8 an inverter; 9 bus bars; 10 a motor unit; 11 an input shaft; 13 auxiliary shafts; 14 an engaging portion; 21 an input gear; 23 countershaft gears; 31a rotor; 32 motor shafts; 35a stator; 35a stator core; 35b a coil; 35c coil side end portions; 40 a stator holder; 41a cylindrical part; 41a outer peripheral surface; 41b inner peripheral surface; 42a bottom plate portion; 43 a bearing holding portion (first bearing holding portion); 44 recess (passage portion); 45b O annular rings (seals); 46 a fitting part; 50 differential device; 51 a ring gear; 55 an output shaft; 60a housing body; 60aa opposite to the inner peripheral surface; 60b bottom; a 60ba bearing holding portion (second bearing holding portion); 60da tank bottoms (bulkheads); a 60db side wall portion (partition wall, first wall portion); 60h through holes; 61a drive body storage space; 61a first opening; 62 inverter housing space; 62a second opening; 63 oil storage space; 63a third opening; 64 oil receiving spaces; 66 partition walls; 68 an inverter cover; 71 ball bearings (second bearings); 72 ball bearings (first bearings); 73 ball bearings; 74 ball bearings; 75 ball bearings; 76 tapered roller bearings; 77 tapered roller bearings; 78 ball bearings; 79 ball bearings; 80 a shaft holding part; 81 a first holder; 82a bearing holding portion; 82b a bearing holding portion; 83a bearing holding portion; 84 set screws; 86 a second holder; 87 an opening; 88 an enclosing part; 88e bearing holding part; 88f a bearing holding portion; j1 motor axis; a J2 axis; j3 countershaft axis; o oil; w refrigerant.

Claims (7)

1. A motor unit, comprising:

a motor having a rotor with a motor shaft that rotates centering on a motor axis and a stator located radially outside the rotor;

a first bearing that supports the motor shaft;

a stator holder that holds the stator; and

a housing main body that houses the motor and the stator holder,

the stator holder has:

a cylindrical portion surrounding the stator from a radially outer side; and

a bottom plate portion extending radially inward from one axial end of the cylindrical portion,

the housing main body has an opposing inner circumferential surface that radially opposes the outer circumferential surface of the cylindrical portion,

a passage portion through which a refrigerant flows is provided between the outer peripheral surface of the cylindrical portion and the opposing inner peripheral surface,

the bottom plate portion holds the first bearing.

2. The motor unit of claim 1,

the stator has an annular stator core and a coil wound around the stator core,

the coil has coil side end portions protruding from the stator core portion to both axial sides,

the axial position of the first bearing overlaps with the axial position of one of the coil side end portions.

3. The motor unit of claim 1 or 2,

further comprising a resolver measuring the rotational speed of the motor shaft,

the resolver comprises:

a resolver stator supported by the bottom plate portion; and

a resolver rotor that rotates with the motor shaft about a motor axis.

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

a fitting portion that fits into the opposing inner circumferential surface is provided on an outer circumferential surface of the cylindrical portion.

5. The motor unit according to any one of claims 1 to 4, further comprising:

a gear part connected to the other axial side of the motor and housed in the housing main body; and

an oil that lubricates the gear portion and is housed in the case main body,

a seal portion extending in a circumferential direction is provided between the outer circumferential surface of the cylindrical portion and the opposing inner circumferential surface,

the seal portions are respectively located on both axial sides of the passage portion.

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

the motor shaft is a hollow shaft and,

a gear portion connected to the other axial side of the motor and housed in the housing main body,

the gear portion has:

an output shaft, a portion of which is disposed inside the motor shaft and rotates about the motor axis; and

a plurality of gears that transmit power from the motor shaft to the output shaft,

the housing main body supports the output shaft via a second bearing on one side in the axial direction of the first bearing.

7. The motor unit of claim 6,

a resolver is disposed between the first bearing and the second bearing in the axial direction, and measures a rotation speed of the motor shaft.

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