WO2021166300A1 - Motor unit and motor unit manufacturing method - Google Patents

Abstract

One embodiment of the motor unit according to the present invention is provided with: a motor having a motor shaft extending along a motor axis line; a gear portion connected to one side of the motor in the axial direction; a housing body provided with a driver housing space for housing the motor and the gear portion; and an axis holding portion disposed in the driver housing space. The housing body has an opening portion for exposing the driver housing space to the one side in the axial direction. The motor shaft is a hollow shaft. The gear portion has: an output shaft, a part of which is disposed inside the motor shaft and which rotates around the motor axis line; and a plurality of gears for transmitting power from the motor shaft to the output shaft. The axis holding portion has a first bearing positioned between the motor and the gear portion in the axial direction and supports the motor shaft.

Description

Motor unit and manufacturing method of motor unit

The present invention relates to a motor unit and a method for manufacturing the motor unit.
The present application claims priority based on Japanese Patent Application No. 2020-026148 filed on February 19, 2020, the contents of which are incorporated herein by reference.

In recent years, the development of drive devices to be mounted on electric vehicles has been actively carried out. Patent Document 1 describes a motor-type power unit (motor unit) that has been miniaturized by passing an output shaft inside a rotor shaft having a hollow structure.

Japanese Unexamined Patent Publication No. 2009-121549

In the conventional structure, a partition wall is provided in the housing for accommodating the motor and the gear portion, and the partition wall supports the shaft between the motor and the gear portion to suppress the eccentricity of the shaft. In such a structure, there is a problem that the structure of the housing becomes complicated, such as the need to divide the housing into a large number, and the time required for the assembly process becomes long accordingly.

One aspect of the present invention is to provide a motor unit that can simplify the assembly process.

One aspect of the motor unit of the present invention is a motor having a motor shaft extending along the motor axis, a gear portion connected to one side in the axial direction of the motor, and a drive body accommodating the motor and the gear portion. A housing main body provided with a storage space and a shaft holding portion arranged in the drive body storage space are provided. The housing body has an opening that exposes the drive body accommodation space to one side in the axial direction. The motor shaft is a hollow shaft. The gear portion includes an output shaft whose part is arranged inside the motor shaft and rotates around the motor axis, and a plurality of gears for transmitting power from the motor shaft to the output shaft. The shaft holding portion has a first bearing that is located between the motor and the gear portion in the axial direction and supports the motor shaft.
Further, one aspect of the method for manufacturing a motor unit of the present invention includes a motor that rotates a motor shaft extending along a motor axis, a gear portion connected to one side in the axial direction of the motor, a shaft holding portion, and these. This is a method for manufacturing a motor unit including a housing body. The housing body has a drive body accommodating space for accommodating the motor and the gear portion, and an opening for exposing the drive body accommodating space on one side in the axial direction. The gear portion includes an output shaft whose part is arranged inside the motor shaft and rotates around the motor axis, and a plurality of gears for transmitting power from the motor shaft to the output shaft. An output shaft assembly step of accommodating the output shaft from the opening into the drive body accommodating space and assembling the other end of the output shaft in the axial direction to the housing body, and accommodating the motor from the opening to the drive body. A motor assembling step of accommodating the motor shaft in the space and inserting the output shaft into the inside of the motor shaft, and accommodating the shaft holding portion from the opening into the drive body accommodating space, and accommodating the output shaft and the motor via a bearing. It includes a shaft holding portion assembling step of supporting the shaft, and a gear portion assembling step of accommodating the gear portion from the opening to the drive body accommodating space.

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

FIG. 1 is a conceptual diagram of a motor unit of one embodiment. FIG. 2 is a perspective view of the motor unit of one embodiment. FIG. 3 is an exploded perspective view of a shaft holding portion of the motor unit of one embodiment. FIG. 4 is a schematic view of the oil pump of the motor unit of one embodiment.

Hereinafter, the motor unit 10 according to the 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. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure may be different from the actual structure.

FIG. 1 is a conceptual diagram of the motor unit 10. FIG. 2 is a perspective view of the motor unit 10.
In the following description, the direction of gravity will be defined based on the positional relationship when the motor unit 10 is mounted on a vehicle located on a horizontal road surface. Further, in the drawings, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate.

In the present embodiment, the Z-axis direction indicates the vertical direction (that is, the vertical direction), the + Z direction is the upper side (opposite the gravity direction), and the −Z direction is the lower side (gravity direction). Therefore, in the present specification, the term "upper side" means the upper side with respect to the direction of gravity. The X-axis direction is orthogonal to the Z-axis direction and indicates the front-rear direction of the vehicle on which the motor unit 10 is mounted. 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 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 vehicle left side, and the -Y direction is the vehicle right side. Is.

Unless otherwise specified in the following description, the direction parallel to the motor axis J1 of the motor 1 (direction parallel to the Y axis) is simply referred to as "axial direction". Further, the direction on the + Y side in the axial direction is referred to as one side in the axial direction, and the −Y side is referred to as the other side in the axial direction. Further, the radial direction centered on the motor axis J1 is simply called the "diameter direction", and the circumferential direction centered on the motor axis J1, that is, the circumference of the motor axis J1 is simply called the "circumferential direction".
The motor axis J1 and the counter axis J3 described later are virtual axes that do not actually exist.

The motor unit 10 is mounted on the vehicle and rotates the wheels H to move the vehicle forward or backward. The motor unit 10 is mounted on, for example, an electric vehicle (EV). The motor unit 10 may be mounted on a vehicle powered by a motor, 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 accommodating the motor 1, the gear portion 5 and the inverter 8, and a shaft holding a shaft in the housing 6. It includes a holding portion 80, a stator holder 40 that holds the stator 35 of the motor 1 in the housing 6, and oil O.

(housing)
The housing 6 is made of, for example, aluminum die-cast. The housing 6 is located below the housing body 60, the closing member 67 located on one side (+ Y side) of the housing body 60 in the axial direction, the inverter cover 68 located on the upper side of the housing body 60, and the housing body 60. It has a bottom lid member 69 and the like. That is, the motor unit 10 has a housing body 60, a closing member 67, an inverter cover 68, and a bottom lid member 69. The housing 6 is configured by fastening the housing body 60, the closing member 67, the inverter cover 68, and the bottom lid member 69 to each other.

The housing body 60 is provided with a drive body accommodating space 61, an inverter accommodating space 62, and an oil storage space 63. The inverter accommodating space 62 is arranged on the upper side of the drive body accommodating space 61, and the oil storage space 63 is arranged on the lower side.

The drive body accommodating space 61 is a connected space accommodating the motor 1, the gear portion 5, the shaft holding portion 80, the stator holder 40, and the oil O. Further, the inverter accommodating space 62 is a space accommodating the inverter 8. The oil storage space 63 is a space for storing the oil O circulating in the drive body accommodating space 61. In this way, the housing 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 each space.

A communication hole 65 connected to the oil storage space 63 is provided on the lower wall surface of the drive body accommodating space 61. The oil O in the lower region of the drive body accommodating space 61 flows into the oil storage space 63 through the communication hole 65. Oil O is accumulated in the lower region of the drive body accommodating space 61 and the oil storage space 63.

Oil O circulates in the oil passage 90 provided in the housing 6. The oil O functions not only as a lubricating oil for lubricating the gear portion 5 but also as a cooling oil for cooling the motor 1. As the oil O, it is preferable to use an oil equivalent to a low-viscosity lubricating oil for automatic transmission (ATF: Automatic Transmission Fluid).

A part of the ring gear 51, which will be described later, of the gear portion 5 is immersed in the oil O that collects in the lower region of the drive body accommodating space 61. The oil O is scooped up by the operation of the ring gear 51 and diffused into the drive body accommodating space 61. The oil O diffused in the drive body accommodating space 61 is supplied to each gear of the gear portion 5 in the drive body accommodating space 61, and the oil O is distributed to the tooth surfaces of the gears. 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 accommodating space 61.

The housing body 60 has a first opening 61a that exposes the drive body accommodation space 61 on one side (+ Y side) in the axial direction, a second opening 62a that exposes the inverter accommodation space 62 upward, and an oil storage space. It has a third opening 63a that exposes the 63 downwards. The first opening 61a is covered with the closing member 67. The second opening 62a is covered with the inverter cover 68. The third opening 63a is covered by the bottom lid member 69.

The housing body 60 is radially extended from an opening of a tubular portion 60a centered on the motor axis J1, a bottom portion 60b that covers the other side of the tubular portion 60a in the axial direction, and an opening on one side of the tubular portion 60a in the axial direction. It has an expansion portion 60c, a box-shaped portion 60d arranged on the upper side of the tubular portion 60a, and a storage wall portion 60e located on the lower side of the tubular portion 60a. The box-shaped portion 60d surrounds the inverter accommodating space 62. The box-shaped portion 60d has a second opening 62a. The storage wall portion 60e surrounds the oil storage space 63. The storage wall portion 60e has a third opening 63a.

The tubular portion 60a surrounds the motor 1 from the outside in the radial direction. The bottom portion 60b is located on the other side (−Y side) of the motor 1 in the axial direction. The bottom portion 60b has a bearing holding portion 60ba that holds the ball bearing 71. The bottom 60b supports the output shaft 55 via a ball bearing 71. The bottom 60b supports the oil pump 96.

The expansion portion 60c faces the closing member 67 in the axial direction. The expansion portion 60c includes an overhanging portion 60ca extending from the opening of the tubular portion 60a along a plane orthogonal to the axial direction, and an outer edge portion 60cc extending from the overhanging portion 60ca toward one side (+ Y side) in the axial direction. Have. The closing member 67 is fastened to the outer edge portion 60cc by using a fastening member such as a bolt.

The closing member 67 covers the first opening 61a. The closing member 67, the tubular portion 60a, the bottom portion 60b, and the expansion portion 60c of the housing body 60 surround the drive body accommodating space 61. Therefore, by separating the closing member 67 from the housing body 60, the drive body accommodating space 61 is exposed on one side in the axial direction. The shape of the closing member 67 is a concave shape that opens on the other side (−Y side) in the axial direction. The closing member 67 supports the counter shaft 13, which will be described later, via the ball bearing 79. Further, the closing member 67 rotatably supports the gear housing 52 and the ring gear 51, which will be described later, via the conical roller bearing 77.

According to the present embodiment, the first opening 61a of the housing body 60 accommodates the motor 1, the gear portion 5, the shaft holding portion 80, and the stator holder 40 on one side (+ Y side) of the drive body accommodation space 61 in the axial direction. ). The motor 1, the gear portion 5, the shaft holding portion 80, and the stator holder 40 are assembled inside the housing body 60 from the first opening 61a.

The assembly process of the motor unit 10 is performed by sequentially assembling the motor 1, the gear portion 5, and the like inside the housing body 60. Generally, the posture of the housing body 60 is changed according to the assembling direction of each member. However, when the weight of the housing body 60 is large, the procedure for changing the posture of the housing body 60 lengthens 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 assembled to the housing body 60 from one direction, thereby simplifying the assembling process and performing assembling. The required cost can be reduced.

Further, according to the present embodiment, the housing body 60 has a bottom portion 60b that closes the drive body accommodating space 61 on the other side (−Y side) of the motor 1 in the axial direction. Therefore, a member (output shaft 55 or the like) to be accommodated in the drive body accommodating space 61 from one side (+ Y side) in the axial direction can be supported by the bottom portion 60b, which improves the assembling accuracy and simplifies the assembling process. be able to. Further, since the bottom portion 60b is a part of the housing main body 60, the other side in the axial direction of the drive body accommodating space 61 is closed in advance. Therefore, the number of parts can be reduced and the assembly process can be simplified as compared with the case where the drive body accommodating space 61 is opened on both sides in the axial direction.

The box-shaped portion 60d has a box shape surrounding the inverter 8. The box-shaped portion 60d opens upward to form a second opening 62a. The box-shaped portion 60d and the inverter cover 68 form a wall surface of the inverter accommodating space 62. The box-shaped portion 60d is connected to the upper side of the tubular portion 60a. A part of the box-shaped portion 60d is composed of a part of the tubular portion 60a and the expansion portion 60c.

The box-shaped portion 60d includes 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, and the inverter 8 and the gear portion on one side in the axial direction of the inverter 8. It has a side wall portion 60db (partition wall, first wall portion) located between the side wall portion and the other side wall portion. The box bottom portion 60da is a part of the tubular portion 60a and faces the second opening in the vertical direction. The side wall portion 60db is a part of the expansion portion 60c and extends upward from the box bottom portion 60da. The box bottom portion 60da and the side wall portion 60db function as partition walls 66 that partition the drive body accommodation space 61 and the inverter accommodation space 62. Further, the side wall portion 60db is provided with a through hole 60h. The through hole 60h communicates the drive body accommodating space 61 and the inverter accommodating space 62. As will be described later, the bus bar 9 passes through the through hole 60h.

According to the present embodiment, the housing main body 60 has a partition wall 66 that partitions the drive body accommodation space 61 and the inverter accommodation space 62. That is, according to the present embodiment, the member accommodating the motor 1 and the gear portion 5 and the member accommodating the inverter 8 are composed of a single member (housing body 60). Therefore, the rigidity of the housing body 60 as a whole is increased, and the effect of suppressing vibration is enhanced. As a result, the transmission of vibration caused by the driving of the motor 1 and the gear portion 5 to the inverter 8 is suppressed, and the load on the inverter 8 can be suppressed.

The inverter cover 68 is fixed to the box-shaped portion 60d. 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 (that is, the surface facing the inside of the inverter accommodating space 62). As a result, the inverter cover 68 supports the inverter 8.

According to this embodiment, the inverter 8 is fixed to the inverter cover 68 that can be detached from the housing body 60. Therefore, the inverter 8 can be easily detached from the motor unit 10 by releasing the fastening between the inverter cover 68 and the housing body 60 when performing maintenance of the motor unit 10 such as periodic inspection and parts replacement. This step can be performed even when the motor unit 10 is mounted on the vehicle, and the maintainability of the inverter 8 can be improved.

The top plate portion 68a may be provided with a flow path for a refrigerant for cooling the inverter 8. In this case, the flow path of the refrigerant is provided on the inverter cover 68, which is a member separate from the housing body 60 in contact with the motor 1. According to this embodiment, since the heat of the motor 1 is not easily transferred to the refrigerant, the temperature of the inverter 8 can be suppressed to be lower than the temperature of the motor. Further, the flow path provided in the top plate portion 68a may be connected to the passage portion (recessed portion 44) described later. In this case, as the refrigerant, the refrigerant that cools the inverter 8 and the refrigerant that cools the motor 1 can be shared.

(motor)
The motor 1 is a motor generator having both a function as a 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 at the time of regeneration. The motor 1 of this embodiment is a three-phase AC motor.

Motor 1 is connected to inverter 8. The inverter 8 converts the direct current supplied from the battery (not shown) into an alternating current and supplies the direct current to the motor 1. Each rotation speed of the motor 1 is controlled by controlling the inverter 8.

The motor 1 has a rotor 31 and a stator 35 located on the radial outer side of the rotor 31. The rotor 31 can rotate about the motor axis J1. The stator 35 is annular. The stator 35 surrounds the rotor 31 from the radial 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 31a. That is, the motor 1 has a motor shaft 32.

The rotor 31 (that is, the motor shaft 32, the rotor core 31a, and the rotor magnet) rotates about the 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 along the axial direction. A plurality of rotor magnets are fixed to the rotor core 31a. The plurality of rotor magnets are arranged along the circumferential direction with alternating magnetic poles.

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

The motor shaft 32 has a first end portion 32A located on one side (+ Y side) in the axial direction and a second end portion 32B located on the other side (−Y side) in the axial direction.

The first end 32A of the motor shaft 32 is rotatably supported by the ball bearing 73. A female spline 32b is provided in the 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 32B of the motor shaft 32 is rotatably supported by the ball bearing 72. A resolver rotor 3a is fixed to the outer peripheral surface of the second end portion 32B. The resolver rotor 3a rotates around the motor axis J1 together with the motor shaft 32. The resolver rotor 3a is located on the other side (−Y side) in the axial direction from the ball bearing 72 that supports the second end portion 32B.

The stator 35 has an annular stator core 35a, a coil 35b wound around the stator core 35a, and an insulator (not shown) interposed between the stator core 35a and the coil 35b. The stator core 35a has a plurality of teeth protruding inward in the radial direction of the motor axis J1. A coil wire is wound around the tooth. The coil wire wound around the tooth constitutes the coil 35b.

The coil 35b has a coil end portion 35c protruding from the stator core 35a on both sides in the axial direction. One coil end portion 35c projects axially from one end face of the stator core 35a in the axial direction, and the other coil end portion 35c protrudes axially from the other end face of the stator core 35a in the axial direction. A connecting coil wire 35d extends from the coil end portion 35c on one side in the axial direction. The connecting coil wire 35d has a twisted coil wire and an insulating tube that covers the outer circumference of the coil wire. Since the motor 1 of the present embodiment is a three-phase AC motor, it has three connecting coil wires 35d corresponding to each phase. The connection coil wire 35d is connected to the inverter 8 via the bus bar 9.

(Gear part)
The gear portion 5 is connected to one side (+ Y side) of the motor 1 in the axial direction. The gear portion 5 transmits the power of the motor 1 and outputs the power from the output shaft 55. The gear unit 5 incorporates a plurality of mechanisms responsible for power transmission between the drive source and the driven device.

The gear portion 5 includes 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 can rotate around either the motor axis J1 or the counter axis J3, respectively. In this embodiment, the motor axis J1 and the counter axis J3 extend parallel to each other. Further, the motor axis J1 and the counter axis J3 are parallel to the width direction of the vehicle. In the following description, the axial direction means the axial direction of the motor axis J1. That is, the axial direction in the present specification means a direction parallel to the motor axis J1 and a vehicle width direction.

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

The input shaft 11 has a first end portion 11A located on one side (+ Y side) in the axial direction and a second end portion 11B located on the other side (−Y side) in the axial direction. The input shaft 11 is rotatably supported by a ball bearing 74 between the first end 11A and the second end 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 fits into the female spline 32b of the motor shaft 32. As a result, the first end 32A of the motor shaft 32 and the second end 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 rotation of the motor 1 is transmitted to the input shaft 11 to rotate the input shaft 11.

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 around the motor axis J1 together with the input shaft 11. In this embodiment, the input gear 21 and the input shaft 11 are a single member. However, the input gear 21 may be a separate member assembled on the outer peripheral surface of the input shaft 11.

The counter shaft 13 extends along the counter axis J3. The counter shaft 13 rotates around the counter axis J3. The counter shaft 13 has a first end portion 13A located on one side (+ Y side) in the axial direction and a second end portion 13B located on the other side (−Y side) in the axial direction.

The first end 13A of the counter shaft 13 is rotatably supported by a ball bearing 79. The second end 13B of the counter shaft 13 is rotatably supported by a 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 one side (+ Y side) of the counter gear in the axial direction.

The counter gear 23 rotates around the counter axis J3 together with the counter shaft 13. The counter gear 23 meshes with the input gear 21.

The drive gear 24 rotates around the counter axis J3 together with the counter shaft 13 and the counter gear 23.

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 around 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 device 50 is arranged around the motor axis J1. That is, the differential device 50 is arranged 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 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.

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

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

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

The output shaft 55 extends along the motor axis J1. The output shaft 55 rotates around the motor axis J1. The motor unit 10 is provided with a pair of output shafts 55 arranged along the axial direction. The pair of output shafts 55 are connected to the side gear 54 of the differential device 50 at one end of each. 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, each of the pair of output shafts 55 projects to the outside of the housing 6 at the other end. Wheels H are attached to the other end of the output shaft 55. The output shaft 55 outputs power to the outside (road surface via the wheel H).

In the present embodiment, the output shaft 55 is arranged coaxially with the motor shaft 32 and the input shaft 11. One of the pair of output shafts 55 arranged on the other side (−Y side) in the axial direction is passed through the hollow portions 32h and 11h of the motor shaft 32 and the input shaft 11. According to the motor unit 10 of the present embodiment, a part of the output shaft 55 is arranged inside the motor shaft 32 and the input shaft 11, so that the motor 1 and the differential device 50 are coaxially aligned when viewed from the axial direction. 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 and ring gear 51, pinion gear 53a and side gear 54). The gear unit 5 transmits power from the motor shaft 32 to the output shaft 55 by these 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 arranged 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 has a cylindrical portion 41 that surrounds the stator 35 from the outside in the radial direction, and a bottom plate portion 42 that extends radially inward from the end of the cylindrical portion 41 on the other side (−Y side) in the axial direction.

The stator holder 40 is arranged inside the tubular portion 60a of the housing body 60. The tubular portion 60a of the housing body 60 has an opposing inner peripheral surface 60a that faces inward in the radial direction. The facing inner peripheral surface 60aa faces the outer peripheral surface 41a of the cylindrical portion 41 in the radial direction.

The cylindrical portion 41 has a cylindrical shape centered on the motor axis J1. The stator 35 is supported by fitting the outer peripheral surface of the stator 35 to the inner peripheral surface 41b of the cylindrical portion 41. As a result, the stator holder 40 supports the stator 35.

A fitting portion 41p is provided on the inner peripheral surface 41b of the cylindrical portion 41. The fitting portion 41p is provided in the opening on one side (+ Y side) of the cylindrical portion 41 in the axial direction. The inner diameter of the fitting portion 41p is larger than the region where the stator 35 is fitted on the inner peripheral surface 41b. The first retainer 81 of the shaft holding portion 80 is fitted into the fitting portion 41p.

The outer peripheral surface 41a of the cylindrical portion 41 is provided with a recess (passage portion) 44 recessed in the radial direction. The recess 44 extends over the entire circumference around the motor axis J1. The recess 44 opens outward in the radial direction. The opening of the recess 44 is covered by the facing inner peripheral surface 60aa of the housing body 60.

The recess 44 functions as a passage portion through which the refrigerant W flows. The refrigerant W flows along the circumferential direction between the inner wall surface of the recess 44 and the facing inner peripheral surface 60aa. The refrigerant W cools the stator 35 via the stator holder 40. The refrigerant W passes through a heat exchanger (not shown) and is cooled. Therefore, the stator holder 40 and the cylindrical portion 41 of the housing body 60 function as a water jacket that surrounds the stator 35 and allows the refrigerant W to pass therethrough to cool the stator 35.

In the present embodiment, the case where 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 by the facing inner peripheral surface 60aa has been described. However, a configuration may be adopted in which a recess is provided on the facing inner peripheral surface 60aa and the opening of the recess is covered by the outer peripheral surface 41a of the cylindrical portion 41. Further, the configuration for passing the refrigerant W is not limited to this embodiment, and a passage portion for passing the refrigerant W may be provided between the outer peripheral surface 41a of the cylindrical portion 41 and the facing inner peripheral surface 60aa.

A pair of fitting portions 46 that fit into the opposing inner peripheral surfaces 60aa are provided on the outer peripheral 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 one side of the recess 44 in the axial direction, and the other is located on the other side of the recess 44 in the axial direction. According to this embodiment, the stator holder 40 fits into the facing inner peripheral surface 60aa of the housing body 60 at the fitting portion 46. As a result, the positional accuracy of the stator holder 40 in the radial direction with respect to the housing body 60 can be improved.

A pair of concave grooves 45a are provided on the outer peripheral surface 41a of the cylindrical portion 41. The concave groove 45a extends over the entire circumference around the motor axis J1. One of the pair of recessed grooves 45a is located on one side of the recess 44 in the axial direction, and the other is located on the other side of the recess 44 in the axial direction. Both of the pair of recessed grooves 45a are arranged between the pair of fitting portions 46 in the axial direction. The concave groove 45a opens outward in the radial direction. The opening of the groove 45a is covered by the facing inner peripheral surface 60aa of the housing body 60. An O-ring (sealing portion) 45b is housed in each of the pair of recessed grooves 45a. The O-ring 45b is compressed in the radial direction by the facing inner peripheral surface 60aa. As a result, the O-ring 45b functions as a sealing portion.

A configuration may be adopted in which a concave groove for accommodating the O-ring is provided on the facing inner peripheral surface 60aa, and the O-ring is compressed by the outer peripheral surface 41a of the cylindrical portion 41. That is, the O-ring 45b as the sealing portion may be arranged between the outer peripheral surface 41a of the cylindrical portion 41 and the facing inner peripheral surface 60aa and may extend along the circumferential direction.

According to the present embodiment, the O-ring 45b is located on both sides of the recess 44 as the passage portion of the refrigerant W in the axial direction. The O-ring 45b suppresses the refrigerant W from leaking from the recess 44 to both sides in the axial direction. Further, it is possible to prevent the oil O in the drive body accommodating space 61 from entering between the pair of O-rings 45b. As a result, the oil O is prevented from mixing with the refrigerant W in the recess 44.

The bottom plate portion 42 is located on the other side (-Y side) in the axial direction 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 portion 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 that projects from the edge portion of the insertion hole 42a to one side (+ Y side) in the axial direction. The bottom plate portion 42 holds the ball bearing 72. Therefore, the bottom plate portion 42 rotatably supports the motor shaft 32 via the ball bearing 72.

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

According to this embodiment, the bottom plate portion 42 of the stator holder 40 holds the ball bearing 72. Therefore, as compared with the case where a member for holding the ball bearing 72 is separately provided, the entire motor unit 10 can be easily miniaturized 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. As a result, the motor unit 10 can be miniaturized more effectively in the axial direction.

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

According to the present embodiment, the ball bearing 72 is arranged inside the pair of coil end portions 35c of the stator 35 in the radial direction of one coil end portion 35c located on the other side in the axial direction. More specifically, the axial position of the ball bearing 72 overlaps the axial position of one coil end portion 35c located on the other side in the axial direction. Therefore, the ball bearing 72 that supports the second end 32B of the motor shaft 32 can be arranged closer to the first end 32A side. As a result, the ball bearings 72 and 73 that support both ends of the motor shaft 32 can be arranged close to each other, and the eccentricity of the motor shaft 32 can be suppressed. Further, the coil end portion 35c can be cooled and the oil O dropped from the coil end portion 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 arranged inside the insertion hole 42a and on the other side in the axial direction from the ball bearing 72. The resolver stator 3b surrounds the second end 32B of the motor shaft 32 from the outside in the radial direction. The resolver stator 3b faces the resolver rotor 3a in the radial direction.

The resolver stator 3b and the resolver rotor 3a constitute the resolver 3. That is, the motor unit 10 includes a resolver 3. The resolver 3 measures the rotation speed of the motor shaft 32. The resolver 3 is arranged between the ball bearing 71 and the ball bearing 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 has an axial dimension of the motor 1 as compared with the case where the housing body 60 supports the resolver stator 3b. It can be placed closer to the center. As a result, it is possible to prevent the resolver stator 3b from protruding in the axial direction with respect to the motor 1, and the axial dimension of the motor unit 10 can be reduced.

(Shaft holder)
The shaft holding portion 80 is arranged in the drive body 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 includes a first retainer 81, a second retainer 86, ball bearings 73, 74, 75, 78, and a conical roller bearing 76.

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

FIG. 3 is an exploded perspective view of the shaft holding portion 80.
The first retainer 81 has a main body disk portion 82 and a protruding disk portion 83. The main body disk portion 82 and the protruding disk portion 83 are single members 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 so as to be offset from the main body disk portion 82 to one side (+ Y side) in the radial direction and the axial direction.

The main body disk portion 82 has a disk shape centered on the motor axis J1. A first insertion hole 82h penetrating in the axial direction is provided in the center of the main body disk portion 82. The first insertion hole 82h is circular with the motor axis J1 as the center when viewed from the axial direction. Inside the first insertion hole 82h, 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 arranged.

A plurality of screw holes 82s are provided on one side (+ Y side) of the main body disk portion 82 in the axial direction. The plurality of screw holes 82s are arranged along the circumferential direction of the motor axis J1 so as to surround the first insertion hole 82h. A fixing screw 84 for fixing the second retainer 86 is inserted into the screw hole 82s. That is, the second retainer 86 is fixed to the first retainer 81 by a plurality of fixing screws 84 inserted on the other side (−Y side) in the axial direction. As a result, the second retainer 86 can be assembled to the first retainer 81 from the first opening 61a side in the drive body accommodation space 61, so that the assembly process of the motor unit 10 can be simplified. Further, the plurality of fixing screws 84 are arranged along the circumferential direction of the motor axis J1. Therefore, the second retainer 86 can be firmly fixed around the motor axis J1.

The protruding disk portion 83 has a disk shape centered on the counter axis J3. A second insertion hole 83h penetrating in the axial direction is provided in the center of the protruding disk portion 83. Inside the second insertion hole 83h, the second end portion 13B of the counter shaft 13 is arranged.

As shown in FIG. 1, the main body disk portion 82 has an outer edge protruding portion 82c that protrudes from the outer edge to the other side (−Y side) in the axial direction. The outer edge protruding portion 82c has a cylindrical shape centered on the motor axis J1. The outer peripheral surface of the outer edge protruding portion 82c is fitted into the fitting portion 41p of the stator holder 40. As a result, the first retainer 81 is supported by the stator holder 40. Further, the first retainer 81 is fixed to the housing body 60 via the stator holder 40.

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

The bearing holding portion 82a is provided on the surface of the main body disk portion 82 facing the other side (-Y side) in the axial direction. The bearing holding portion 82a holds the ball bearing 73. As a result, 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 one side in the axial direction of the motor 1.

In the present embodiment, the motor 1 and the gear portion 5 are housed in a connected drive body accommodating space 61. Therefore, if the shaft holding portion 80 is not provided, the motor shaft 32 becomes cantilevered and there is a possibility that eccentricity due to rotation becomes remarkable. According to the present embodiment, the shaft holding portion 80 rotatably supports 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 this embodiment, the eccentricity of the motor shaft 32 can be suppressed and the rotational efficiency of the motor shaft 32 can be improved.

The bearing holding portion 82b is provided on the surface of the main body disk portion 82 facing one side (+ Y side) in the axial direction. The bearing holding portion 82b holds the ball bearing 74. As a result, 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 83a. The bearing holding portion 83a is provided on the outer edge of the second insertion hole 83h. The bearing holding portion 83a is provided on a surface of the protruding disk portion 83 facing one side (+ Y side) in the axial direction. 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 retainer 81 rotatably supports not only the shaft (motor shaft 32 and input shaft 11) on the motor axis J1 but also the shaft (counter shaft 13) on the counter axis J3. .. Therefore, by controlling the machining accuracy of the first retainer 81, the distance dimension between the motor axis J1 and the counter axis J3 can be guaranteed, and as a result, the power transmission efficiency between the gears can be improved. Further, by assembling the first retainer 81 to the housing body 60 with a plurality of bearings (ball bearings 73, 78) incorporated, the assembly process can be simplified.

The axial positions of the ball bearing 73 and the ball bearing 78 may overlap each other. Further, the ball bearing 74 and the ball bearing 78 may overlap each other in the axial direction. That is, it is preferable that the positions of the plurality of bearings of the shaft holding portion 80 overlap each other in the axial direction. As a result, the axial dimension of the shaft holding portion 80 can be reduced as compared with the case where the bearings are arranged so as to be displaced, and the drive body accommodating space 61 can be effectively used. Further, in a plurality of bearings having overlapping axial positions, oil O scattered in the radial direction from one bearing can be supplied to another bearing, and the lubricity of the bearing can be improved.

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

The surrounding portion 88 is an annular shape that surrounds the motor axis J1 from the outside in the radial direction. The surrounding portion 88 has a disc portion 88a and a surrounding cylinder portion 88b extending axially from the outer edge of the disc portion 88a to the other side in the axial direction.

The disk portion 88a has a disk shape centered on the motor axis J1. A third insertion hole 88h penetrating in the axial direction is provided in the center of the disk portion 88a. The third insertion hole 88h is circular with the motor axis J1 as the center when viewed from the axial direction. An output shaft 55 is arranged inside the third insertion hole 88h.

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

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

By fixing the second retainer 86 to the first retainer 81, the other side (−Y side) of the notch 88c in the axial direction is closed by the first retainer 81. As a result, 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 the end of the surrounding portion 88 on the other side (-Y side) in the axial direction. More specifically, the flange portion 89 extends radially outward from the end on the other side in the axial direction of the surrounding cylinder portion 88b. 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. A fixing screw 84 inserted into the screw hole 82s of the first retainer 81 is passed through the through hole 89a in order to fix the second retainer 86 to the first retainer 81. As a result, the second retainer 86 is supported by the first retainer 81.

As shown in FIG. 1, the bearing holding portion 88f of the second retainer 86 is provided on the surface of the disk portion 88a facing the other side (−Y side) in the axial direction. The bearing holding portion 88f holds the ball bearing 75. As a result, 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 one side (+ Y side) in the axial direction. The bearing holding portion 88e holds the conical roller bearing 76. As a result, the bearing holding portion 88e rotatably supports the gear housing 52 and the ring gear 51 via the conical roller bearing 76.

According to the present embodiment, the second retainer 86 that supports the output shaft 55 via the ball bearing 75 is fixed to the first retainer 81. The first retainer 81 supports the motor shaft 32 and the input shaft 11 via ball bearings 73 and 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 guaranteed by the assembly accuracy of the second retainer 86 with respect to the first retainer 81. Therefore, it is easy to increase the rotational efficiency of the motor shaft 32 and the input shaft 11.

According to the present embodiment, the shaft holding portion 80 has a surrounding portion 88 that surrounds the motor axis, and the surrounding portion 88 is provided with an opening 87 that opens in the radial direction of the motor axis J1. The opening 87 communicates the inside and outside of the surrounding portion 88. As a result, the oil O scattered in the drive body accommodating space 61 due to the raising of the ring gear 51 or the like can be made to reach the inside of 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 into the drive body accommodating space 61. Therefore, according to the present embodiment, the oil O can be supplied to the ball bearings 74 and 75 from the opening 87, and the lubricity of the ball bearings 74 and 75 can be improved.

In this embodiment, the opening 87 opens upward. Therefore, the oil O that has reached the inside of the surrounding portion 88 from the opening 87 collects inside the surrounding portion 88. That is, the surrounding portion 88 has an oil storage space 64 in which the oil O is stored. Further, the opening 87 and the oil storage space 64 are arranged in the second retainer 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 in the oil storage space 64. A part of the oil O in the oil storage space 64 penetrates into the hollow portion 11h and enhances the lubricity between the inner peripheral surface of the input shaft 11 and the output shaft 55. Further, the oil O is supplied to the male spline 11a and the female spline 32b of the connecting portion between the input shaft 11 and the motor shaft 32, and suppresses wear of the connecting portion. The oil O is scattered from the connecting portion of the male spline 11a and the female spline 32b and is supplied to the ball bearing 73 that supports the motor shaft 32 to improve 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 11A of the input shaft 11 is located in the oil storage space 64. Therefore, the lower end of the input gear 21 is immersed in the oil O accumulated in the oil storage space 64. The oil O is scooped up by the operation of the input gear 21, diffused into the drive body accommodating space 61, and spreads over the tooth surface of each gear.

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

According to the present embodiment, the shaft holding portion 80 has a plurality of bearing holding portions 82a, 82b, 88f, 88e, 83a, respectively, which hold bearings. Of these, the bearing holding portions 82a, 82b, 83a are arranged in the first retainer 81, and the bearing holding portions 88f, 88e are arranged in the second retainer 86. In this way, since the first retainer 81 and the second retainer 86, which are separable from each other, each have a bearing holding portion, the first retainer 81 and the second retainer 86 can be assembled in a separated state. Therefore, the assembly process can be simplified. Further, the bearings can be assembled from both sides of the first retainer 81 and the second retainer 86 in the axial direction, and it is easy to improve the positional accuracy of the bearings in the axial direction and the radial direction.

(Inverter)
As shown in FIG. 1, the inverter 8 is arranged in the inverter accommodation space 62. The inverter 8 is fixed to the inverter cover 68. The inverter 8 is connected to the stator 35 of the motor 1 via the bus bar 9. The inverter 8 converts a direct current into an alternating current and supplies it to the motor 1. That is, the inverter 8 controls the current supplied to the motor 1.

The inverter 8 is arranged on the outer peripheral surface side of the motor 1. More specifically, the inverter 8 is located directly above the motor 1. As a result, the dimensions of the motor unit 10 in the front-rear direction can be reduced. As a result, the dimensions of the motor unit 10 in the vehicle front-rear direction can be reduced as compared with the case where the inverter 8 is arranged in the vehicle front-rear direction with respect to the motor 1. As a result, it is possible to secure a wide crushable zone in the vehicle.

Seen from the axial direction, at least a part of the inverter 8 overlaps with the counter gear 23. By arranging the inverter 8 so as to overlap the counter gear 23, the projected area of the motor unit 10 in the axial direction can be reduced, and the motor unit 10 can be miniaturized.

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

The bus bar 9 has an axial extending portion 9a extending along the axial direction and a radial extending portion 9b extending along the radial direction of the motor axis J1.

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

The axially extending portion 9a passes through the through hole 60h provided in the partition wall 66 that partitions the drive body accommodation space 61 and the inverter accommodation space 62. As a result, the bus bar 9 is arranged so as to straddle between the drive body accommodation space 61 and the inverter accommodation space 62.

The bus bar 9 is held by a bus bar holder (not shown). The bus bar holder is arranged between the inner peripheral surface of the through hole 60h and the bus bar 9, and has a sealing structure that seals between the drive body accommodating space 61 and the inverter accommodating space 62. As a result, the bus bar holder suppresses the oil O in the drive body accommodating space 61 from entering the inverter accommodating space 62.

According to the present embodiment, the through hole 60h through which the bus bar 9 passes is provided in the side wall portion 60db. The side wall portion 60db is located on one side in the axial direction of the inverter 8 and between the inverter 8 and the gear portion 5. Further, the through hole 60h penetrates the side wall portion 60db along the axial direction. As described above, since the drive body accommodating space 61 opens on one side (+ Y side) in the axial direction in the first opening 61a, the assembly worker accommodates the bus bar 9 from the first opening 61a. The bus bar 9 can be assembled to the housing body 60 by accommodating it in the space 61 and inserting it into the through hole 60h. According to the present embodiment, the bus bar 9 can be assembled to the housing body 60 from the first opening 61a like the other members, and the assembly process can be simplified by assembling from one direction.

(Oil channel)
The oil passage 90 is a route of the oil O that circulates the oil O in the housing 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 "oil passage" is not only a "flow path" that forms a stationary flow of oil in one direction, but also a path that temporarily retains oil (for example, oil storage). It is a concept that also includes a space 63) and a path through which oil drips.

The oil passage 90 includes a first flow path 91 that guides the oil O from the oil storage space 63 to the oil pump 96, and a second flow path 97 that extends from the oil pump 96 to the upper side of the motor 1 and supplies the oil O to the motor 1. Has. The oil O reaches the oil pump 96 from the oil storage space 63 via the first flow path 91, and is supplied to the motor 1 from the oil pump 96 via the second flow path 97. Further, the oil O drops 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 housing body 60. The first flow path 91 is connected to the oil pump 96 from the oil storage space 63. On the other hand, the second flow path 97 extends upward from the oil pump 96 and branches, and opens on the upper side of the pair of coil end portions 35c of the stator 35.

The oil pump 96 is located on the other side (-Y side) of the motor 1 in the axial direction. The oil pump 96 is a mechanical pump connected to the output shaft 55 and driven by the rotation of the output shaft 55. The oil pump 96 sucks oil O from the oil storage space 63 and pumps it into the oil passage 90.

FIG. 4 is a schematic view of the oil pump 96 viewed from the axial direction.
The oil pump 96 has a pump case 96a, an external gear 92, and an internal gear 93.

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

The pump chamber 96c has a circular shape centered on the axis J2 that is eccentric with respect to the motor axis J1 when viewed from the axial direction. A suction port 94 and a discharge port 95 are connected to the pump chamber 96c. An external gear 92 and an internal gear 93 are arranged in the pump chamber 96c.

The suction port 94 and the discharge port 95 are opened on the side surface of the pump chamber 96c facing the other side in the axial direction. 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 oil O from the suction port 94 and discharges oil O from the discharge port 95.

The external tooth gear 92 is a gear that can rotate around 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 96c. The external gear 92 has a plurality of tooth portions 92a on the outer peripheral surface. The tooth profile of the tooth portion 92a of the external gear 92 is a trochoid tooth profile.

The internal gear 93 is an annular gear that can rotate around the axis J2 that is eccentric with respect to the motor axis J1. The outer diameter of the internal gear is slightly smaller than the inner diameter of the pump chamber 96c. The outer peripheral surface of the internal gear 93 slidably faces the inner peripheral surface of the pump chamber 96c.

The internal gear 93 surrounds the radial outer side of the external gear 92 and meshes with the external gear 92. The internal gear 93 has a plurality of tooth portions 93a on the inner peripheral surface. The tooth profile of the tooth portion 93a of the internal gear 93 is a trochoid tooth profile.

When the external gear 92 rotates around the motor axis J1, the external gear 92 and the internal gear 93 that meshes with the external gear 92 also rotate around the axis J2. As a result, the gap between the tooth portion 92a of the external gear 92 and the tooth portion 93a of the internal gear 93 moves along the circumferential direction, and the oil pump 96 discharges the oil O in the gap from the suction port 94. Transfer to exit 95. As a result, the oil pump 96 sucks the oil O from the suction port 94 and discharges it from the discharge port 95.

The oil O discharged from the oil pump 96 is supplied to the pair of coil end portions 35c via the second flow path 97, respectively. The oil O supplied to the coil end portion 35c takes heat from the stator 35 while penetrating the entire coil 35b by the capillary force and gravity acting between the coil wires. Further, the oil O drops downward, passes through the holes provided in the stator holder 40, the communication holes 65, and the like, and returns to the oil storage space 63.

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

In the present embodiment, the oil O is stored in the oil storage space 63. Immediately above the oil storage space 63, a motor 1 provided with a passage portion (recess 44) for the refrigerant W is arranged around the oil storage space 63. Therefore, the oil O in the oil storage space 63 is cooled by the refrigerant W. Therefore, the oil O is supplied to the coil end portion 35c in a state where the temperature is lowered, and the coil end portion 35c can be effectively cooled.

(Manufacturing method of motor unit)
Next, as a method of manufacturing the motor unit 10, a procedure for assembling each member to the housing body 60 will be described with reference to FIG.
The method for manufacturing the motor unit 10 mainly includes the following first to ninth steps.

<First step>
The first step is an output shaft assembling step of assembling the output shaft 55 to the housing body 60. Prior to the first step, the bottom lid member 69 is assembled to the housing body 60 in advance. As a result, the bottom lid member 69 covers the third opening 63a of the housing body 60.

In the first step, first, a seal member (not shown) and a ball bearing 71 are assembled to the bearing holding portion 60ba provided on the bottom portion 60b of the housing body 60. Next, the output shaft 55 is accommodated in the drive body accommodating space 61 through the first opening 61a of the housing body 60. Next, the output shaft 55 is assembled to the housing body 60 by inserting the end of the output shaft 55 on the other side (−Y side) in the axial direction into the ball bearing 71. Next, the oil pump 96 is assembled to the output shaft 55.

<Second step>
The second step is a motor assembling step of assembling the motor 1 to the housing body 60. Prior to the second step, the rotor 31 and the stator 35 are assembled in advance. Further, the stator 35 is previously assembled to the stator holder 40 together with the ball bearing 72.

In the second step, first, the pre-assembled stator 35 and the stator holder 40 are accommodated in the drive body accommodating space 61 through the first opening 61a. Further, the fitting portion 46 of the stator holder 40 is fitted into the facing inner peripheral surface 60aa of the tubular portion 60a of the housing body 60. As a result, the stator holder 40 and the stator 35 are fixed to the housing body 60.

In the second step, the rotor 31 is then accommodated in the drive body accommodating space 61 through the first opening 61a while inserting the output shaft 55 into the hollow portion 32h of the motor shaft 32.
By going through the above procedure, in the second step, the motor 1 and the stator holder 40 are accommodated and fixed in the drive body accommodating space 61 through the first opening 61a of the housing body 60.

<Third step>
The third step is a bus bar assembling step of assembling the bus bar 9 to the housing body 60. In the third step, the three bus bars 9 are accommodated in the drive body accommodating space 61 through the first opening 61a of the housing body 60, and are fixed to the housing body 60 through the through holes 60h of the housing body 60. Next, the bus bar 9 is connected to the connecting coil wire 35d extending from the stator 35.

<Fourth step>
The fourth step is a step of assembling the first retainer 81 to the stator holder 40. Prior to the fourth step, the ball bearing 73 and the ball bearing 78 are assembled to the first retainer 81 in advance.

In the fourth step, first, the first retainer 81 is accommodated in the drive body accommodating space 61 through the first opening 61a of the housing body 60, and the motor shaft 32 is inserted into the ball bearing 73. Further, the outer edge protruding portion 82c of the first retainer 81 is fitted into the fitting portion 41p of the stator holder 40, and the first retainer 81 is fixed to the housing body 60 via the stator holder 40. Next, the ball bearing 74 is assembled to the first retainer 81.

<Fifth step>
The fifth step is a step of assembling the input shaft 11, the counter shaft 13, the input gear 21, the counter gear 23, and the drive gear 24 to the housing 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 housed in the drive body accommodating space 61 through the first opening 61a of the housing body 60 and assembled.

<Sixth step>
The sixth step is a step of assembling the second retainer 86 to the first retainer 81. Prior to the sixth step, the ball bearing 75 and the conical roller bearing 76 are assembled in advance on the second retainer 86.

In the sixth step, first, the second retainer 86 is accommodated in the drive body accommodating space 61 through the first opening 61a of the housing body 60, and is inserted into the ball bearing 75 by the output shaft 55. Further, the second retainer 86 is fixed to the first retainer 81.

By going through the procedure of assembling the first retainer 81 and the second retainer 86 in the fourth step and the sixth step, the shaft holding portion 80 is accommodated in the drive body accommodating space 61 from the first opening 61a of the housing body 60. Fix it.

<7th process>
The seventh step is a step of assembling the ring gear 51 and the differential device 50 to the shaft holding portion 80. Prior to the seventh step, the differential device 50 is assembled in advance, and the ring gear 51 is assembled to the gear housing 52 of the differential device 50.

In the seventh step, the gear housing 52 is held by the conical 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 described above are gear section assembling steps in which the gear section 5 is accommodated and fixed in the drive body accommodating space 61 from the first opening 61a.

<8th step>
The eighth step is a step of assembling the closing member 67 to the housing body 60. Prior to the eighth step, the ball bearing 79 and the conical roller bearing 77 are assembled to the closing member 67 in advance.

In the eighth step, first, the closing member 67 is assembled and fastened so as to cover the first opening 61a of the housing body 60. At the same time, the counter shaft 13 is inserted into the ball bearing 79, and the conical roller bearing 77 holds the gear housing 52.

The first to eighth steps described above are steps of assembling each member including the motor 1 and the gear portion 5 into the drive body accommodating space 61 of the housing main body 60. In the first to eighth steps, each member is assembled to the housing body 60 from one side (+ Y side) in the axial direction. According to this embodiment, the first to eighth steps can be performed without changing the posture of the housing body 60, and as a result, the time required for manufacturing the motor unit 10 can be shortened.

<9th step>
The ninth step is a step of assembling the inverter 8 to the housing body 60. Prior to the ninth step, the inverter 8 is assembled to the inverter cover 68 in advance. That is, the step of assembling 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 assembled is fixed to the housing body 60. As a result, the second opening 62a of the housing body 60 is covered with the inverter cover 68 while arranging the inverter 8 in the inverter accommodation space 62. Next, the window portion (not shown) arranged on the upper surface of the inverter cover is opened, the bus bar 9 is connected to the inverter 8 in the inverter accommodation space 62, and the window portion is closed again.

As described above, in the first to eighth steps, each member is assembled to the housing body 60 from the opening direction of the first opening 61a. On the other hand, in the ninth step, the inverter 8 and the inverter cover 68 are assembled to the housing body 60 from the opening direction of the second opening 62a. Therefore, the assembly posture of the housing body 60 is changed prior to performing the ninth step. In the present embodiment, the steps of assembling the motor 1 and the gear portion 5 (first to eighth steps) are performed with the first opening facing upward. Further, the step of assembling the inverter 8 (9th step) is performed with the second opening 62a facing upward. As a result, the assembly work can be facilitated.

Although the embodiments and modifications of the present invention have been described above, the configurations and combinations thereof in the embodiments and modifications are examples, and the configurations are added or omitted within a range that does not deviate from the gist of the present invention. , Replacements and other changes are possible. Further, the present invention is not limited to the embodiments.

1 ... motor, 3 ... resolver, 3a ... resolver rotor, 3b ... resolver stator, 5 ... gear part, 6 ... housing, 8 ... inverter, 9 ... bus bar, 10 ... motor unit, 11 ... input shaft, 13 ... counter shaft, 14 ... meshing part, 21 ... input gear, 23 ... counter gear, 31 ... rotor, 32 ... motor shaft, 35 ... stator, 35a ... stator core, 35b ... coil, 35c ... coil end part, 40 ... stator holder, 41 ... cylinder Part, 41a ... Outer peripheral surface, 41b ... Inner peripheral surface, 42 ... Bottom plate part, 43 ... Bearing holding part, 44 ... Recessed part (passage part), 45b ... O ring (sealing part), 46 ... Fitting part, 50 ... Differential device, 51 ... ring gear, 55 ... output shaft, 60 ... housing body, 60aa ... opposed inner peripheral surface, 60b ... bottom, 60ba ... bearing holding part, 60da ... box bottom (bulkhead), 60db ... side wall (bulkhead, 1st wall), 60h ... through hole, 61 ... drive body accommodation space, 61a ... first opening, 62 ... inverter accommodation space, 62a ... second opening, 63 ... oil storage space, 63a ... third Opening, 64 ... oil storage space, 66 ... partition wall, 68 ... inverter cover, 71 ... ball bearing, 72 ... ball bearing, 73 ... ball bearing (first bearing), 74 ... ball bearing (fifth bearing), 75 ... Ball bearing (2nd bearing), 76 ... Conical roller bearing (4th bearing), 77 ... Conical roller bearing, 78 ... Ball bearing (3rd bearing), 79 ... Ball bearing, 80 ... Shaft holder, 81 ... No. 1 retainer, 82a ... bearing holding part (first bearing holding part), 82b ... bearing holding part, 83a ... bearing holding part, 84 ... fixing screw, 86 ... second retainer, 87 ... opening, 88 ... surrounding part, 88e ... bearing holding part (third bearing holding part), 88f ... bearing holding part (second bearing holding part), J1 ... motor axis, J2 ... axis, J3 ... counter axis, O ... oil, W ... refrigerant

Claims (5)

1. A motor with a motor shaft extending along the motor axis, and
   A gear portion connected to one side in the axial direction of the motor and
   A housing body provided with a drive body accommodating space for accommodating the motor and the gear portion, and
   A shaft holding portion arranged in the drive body accommodating space is provided.
   The housing body has an opening that exposes the drive body accommodation space to one side in the axial direction.
   The motor shaft is a hollow shaft.
   The gear part
   An output shaft, part of which is located inside the motor shaft and rotates around the motor axis,
   It has a plurality of gears that transmit power from the motor shaft to the output shaft.
   The shaft holding portion is a motor unit having a first bearing located between the motor and the gear portion in the axial direction and supporting the motor shaft.
2. The gear portion has a counter shaft extending along a counter axis extending parallel to the motor axis and rotating around the counter axis, and a counter gear provided on the outer peripheral surface of the counter shaft.
   The motor unit according to claim 1, wherein the shaft holding portion includes a second bearing that supports the output shaft and a third bearing that supports the counter shaft.
3. The motor unit according to claim 2, wherein the plurality of bearings of the shaft holding portion overlap each other in axial positions.
4. The shaft holding portion is
   The first retainer fixed to the housing body and
   It has a second retainer fixed to the first retainer from one side in the axial direction.
   The first retainer has a first bearing holding portion that holds the first bearing.
   The motor unit according to claim 2 or 3, wherein the second retainer has a second bearing holding portion for holding the second bearing.
5. A method for manufacturing a motor unit including a motor for rotating a motor shaft extending along a motor axis, a gear portion connected to one side in the axial direction of the motor, a shaft holding portion, and a housing body for accommodating these.
   The housing body
   A drive body accommodating space for accommodating the motor and the gear portion, and
   It has an opening that exposes the drive body accommodation space to one side in the axial direction.
   The gear part
   An output shaft, part of which is located inside the motor shaft and rotates around the motor axis,
   It has a plurality of gears that transmit power from the motor shaft to the output shaft.
   An output shaft assembly step of accommodating the output shaft from the opening into the drive body accommodating space and assembling the other end of the output shaft in the axial direction to the housing body.
   A motor assembly step of accommodating the motor from the opening into the drive body accommodating space and inserting the motor into the output shaft inside the motor shaft.
   A shaft holding portion assembling step of accommodating the shaft holding portion from the opening to the driving body accommodating space and supporting the output shaft and the motor shaft via bearings.
   It has a gear portion assembling step of accommodating the gear portion from the opening to the drive body accommodating space.
   How to manufacture a motor unit.

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