CN115152133A - Motor unit - Google Patents

Abstract

One aspect of the motor unit of the present invention includes: a motor having a motor shaft extending along an axis of the motor; a gear part connected to one axial side of the motor; and a shaft holding part axially positioned on the motor and the gear part; and the housing body, the housing body is provided with a drive body housing space for housing the motor, the gear part, and the shaft holding part. The motor shaft is a hollow shaft. The gear portion includes an output shaft, a part of which is disposed inside the motor shaft, and the output shaft rotates around the motor axis, and a plurality of gears that transmit power from the motor shaft to the output shaft. The shaft holding part has: a first bearing that rotatably supports the motor shaft; a first holder that holds the first bearing; and a second bearing that rotatably supports the output shaft ; and a second retainer, the second retainer is fixed to the first retainer from one axial side and retains the second bearing.

Description

motor unit

technical field

The present invention relates to a motor unit.

This application claims priority based on Japanese Patent Application No. 2020-026151 for which it applied on February 19, 2020, and uses the content here.

Background technique

In recent years, the development of the drive apparatus mounted in an electric vehicle has progressed widely. Patent Document 1 describes a device (motor unit) that achieves miniaturization by passing shafts for driving wheels through a plurality of hollow shafts.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2010-53997

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

In the conventional structure, a part of the shaft holding structure for holding the shaft protrudes from the inner wall surface of the housing. At this time, since the shaft holding portion has a cantilever structure, there is a problem that it is difficult to suppress vibration of the shaft.

An object of one aspect of the present invention is to provide a motor unit having a shaft holding portion capable of suppressing vibration of a shaft.

Technical solutions adopted to solve technical problems

One aspect of the motor unit of the present invention includes: a motor having a motor shaft extending along a motor axis; a gear portion connected to one axial side of the motor; and a shaft holding portion, the shaft a holding portion located between the motor and the gear portion in the axial direction; and a housing body provided with a drive body housing space for the motor, the gear portion, and the gear portion. The shaft holding portion is accommodated. The motor shaft is a hollow shaft. The gear portion includes: an output shaft, a part of which is disposed inside the motor shaft, and the output shaft rotates around the motor axis; and a plurality of gears that transmit power from the The motor shaft is transmitted to the output shaft. The shaft holding portion includes: a first bearing that rotatably supports the motor shaft; a first holder that holds the first bearing; and a second bearing that the second bearing rotatably supports the output shaft; and a second retainer that is fixed to the first retainer from one side in the axial direction and retains the second bearing .

Invention effect

According to one aspect of the present invention, there is provided a motor unit having a shaft holding portion capable of suppressing vibration of the shaft.

Description of 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.

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

4 is a schematic diagram of an oil pump of a motor unit according to an embodiment.

Detailed ways

Hereinafter, the motor unit 10 according to one embodiment of the present invention will be described with reference to the drawings. In addition, the scope of the present invention is not limited to the following embodiments, but can be arbitrarily changed within the scope of the technical idea of the present invention. In addition, in the following drawings, in order to facilitate understanding of each structure, the scale, number, etc. 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 is defined based on the positional relationship in the case where the motor unit 10 is mounted on a vehicle positioned on a horizontal road surface. In addition, in the drawings, as a three-dimensional rectangular coordinate system, an XYZ coordinate system is appropriately shown.

In this embodiment, the Z-axis direction represents the vertical direction (ie, the vertical direction), the +Z direction is the upper side (the opposite side to the gravitational direction), and the −Z direction is the lower side (the gravitational direction). Therefore, in this specification, when it is simply referred to as the upper side, it means the upper side in the direction of gravity. In addition, the X-axis direction is a direction orthogonal to the Z-axis direction, and represents the front-rear direction of the vehicle on which the motor unit 10 is mounted, the +X direction is the vehicle front, and the −X direction is the vehicle rear. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction, and represents the width direction (left-right direction) of the vehicle, the +Y direction is the vehicle left, and the −Y direction is the vehicle right.

In the following description, unless otherwise specified, 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". In addition, 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. In addition, the radial direction centered on the motor axis J1 is simply referred to as "radial direction", and the circumferential direction centered on the motor axis J1, that is, the direction around the axis of the motor axis J1 is simply referred to as "circumferential direction".

In addition, the motor axis J1 and the counter shaft axis J3 described later are imaginary axes that do not actually exist.

The motor unit 10 is installed in the vehicle and rotates the wheels H to move the vehicle forward or backward. The motor unit 10 is installed in, for example, an electric vehicle (EV). In addition, the motor unit 10 may be installed in a vehicle using a motor as a power source, such as a hybrid vehicle (HEV) and a plug-in hybrid vehicle (PHV).

As shown in FIG. 1 , the motor unit 10 includes a motor 1 , a gear unit 5 , an inverter 8 , a casing 6 that accommodates the motor 1 , the gear unit 5 , and the inverter 8 , and a shaft holder that holds the shaft in the casing 6 Part 80 , the stator holder 40 and the oil O that hold the stator 35 of the motor 1 in the casing 6 .

(shell)

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

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

The drive body housing space 61 is an integrated space for housing the motor 1 , the gear portion 5 , the shaft holding portion 80 , the stator holder 40 , and the oil O. In addition, the inverter accommodation space 62 is a space in which the inverter 8 is accommodated. The oil storage space 63 is a space for storing the oil O circulating in the driving body storage 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 each space.

A communication hole 65 connected to the oil storage space 63 is provided on the lower wall surface of the driving body storage space 61 . The oil O in the lower region of the driving body storage space 61 flows into the oil storage space 63 from the communication hole 65 . The oil O is stored in the lower region of the driving body storage space 61 and the oil storage space 63 .

The oil O circulates in the oil passage 90 provided in the casing 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 a low-viscosity lubricating oil for automatic transmissions (ATF: Automatic Transmission Fluid).

A part of the later-described ring gear 51 of the gear portion 5 is immersed in the oil O accumulated in the lower region of the driving body housing space 61 . The oil O is lifted up by the action of the ring gear 51 and spreads into the driving body storage space 61 . The oil O diffused into the driving body housing space 61 is supplied to each gear of the gear portion 5 in the driving body housing space 61 so that the oil O spreads over the tooth surfaces of the gears. The oil O supplied to the gear portion 5 and used for lubrication drips and is collected in the lower region of the driving body housing space 61 .

The housing body 60 has a first opening 61a that exposes the driver housing space 61 to one side in the axial direction (+Y side), and a second opening 62a that exposes the driver housing space 61 to one side (+Y side) in the axial direction. The inverter housing space 62 is exposed upward; and the third opening 63a exposes the oil storage space 63 to the lower side. The first opening portion 61 a is covered by the closing member 67 . The second opening portion 62 a is covered by the inverter cover 68 . The third opening portion 63 a is covered by the bottom cover member 69 .

The housing body 60 has a cylindrical portion 60a centered on the motor axis J1, a bottom portion 60b that covers the other axial side of the cylindrical portion 60a, and an expanded portion 60c that expands A portion 60c radially expands from an opening on one axial side of the cylindrical portion 60a; a box-like portion 60d disposed on the upper side of the cylindrical portion 60a; and a storage wall portion 60e that stores The wall portion 60e is located on the lower side of the cylindrical portion 60a. The box-shaped portion 60d surrounds the inverter storage space 62 . The box-shaped portion 60d has a second opening portion 62a. The storage wall portion 60e surrounds the oil storage space 63 . The storage wall portion 60e has a third opening portion 63a.

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

The expanded portion 60c is opposed to the blocking member 67 in the axial direction. The expansion 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 extending from the protruding portion 60ca extends to one side in the axial direction (+Y side). The blocking member 67 is fastened to the outer edge portion 60cb using fastening members such as bolts.

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

According to the present embodiment, the first opening 61 a of the housing body 60 causes the drive body housing space 61 that houses the motor 1 , the gear portion 5 , the shaft holding portion 80 , and the stator holder 40 to face the axial direction side (+Y side) exposed. The motor 1 , the gear portion 5 , the shaft holding portion 80 , and the stator holder 40 are incorporated into the inside of the housing body 60 from the first opening portion 61 a.

The assembly process of the motor unit 10 is performed by sequentially attaching the motor 1 , the gear portion 5 , and the like to the inside of the housing main body 60 . Generally speaking, the posture of the casing main body 60 is changed by aligning the mounting directions of the respective members. However, when the weight of the case main body 60 is large, the step of changing the posture of the case main body 60 increases the work time of the assembly process.

According to the present embodiment, the motor 1 , the gear part 5 , the shaft holder 80 and the stator holder 40 can be attached to the housing body 60 from one direction, thereby simplifying the assembly process and reducing the cost required for assembly.

Further, according to the present embodiment, the housing body 60 has the bottom portion 60 b that closes the drive body housing space 61 on the other side (−Y side) in the axial direction of the motor 1 . Therefore, members (the output shaft 55 and the like) accommodated in the drive body accommodation space 61 from the axial direction side (+Y side) can be supported by the bottom portion 60b, the installation accuracy can be improved, and the installation process can be simplified. In addition, since the bottom part 60b is a part of the housing main body 60, the axial direction other side of the drive body accommodation space 61 is closed beforehand. Therefore, compared with the case where the driver housing space 61 is opened on both sides in the axial direction, the number of parts 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 opened to the upper side to constitute the second opening portion 62a. The box-shaped portion 60d and the inverter cover 68 constitute the wall surface of the inverter storage space 62 . The box-shaped portion 60d is connected to the upper side of the cylindrical portion 60a. A part of the box-shaped part 60d is comprised by the cylindrical part 60a and part of the expansion part 60c.

The box-shaped portion 60d has a box bottom portion (partition wall, second wall portion) 60da, a side wall portion 60db (partition wall, first partition wall) and other side wall portions, and the box bottom portion 60da is located at the motor 1 in the radial direction of the motor axis J1. Between the inverter 8 and the inverter 8 , 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 . The box bottom portion 60da is a part of the cylindrical portion 60a and faces the second opening in the up-down direction. The side wall portion 60db is a part of the expansion portion 60c, and extends upward from the tank bottom portion 60da. The box 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 . Moreover, the through-hole 60h is provided in the side wall part 60db. The through hole 60h communicates the driver housing space 61 and the inverter housing space 62 . As described later, the bus bar 9 passes through the through hole 60h.

According to the present embodiment, the case main body 60 has the partition wall 66 which 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 case body 60 as a whole can be improved, and the effect of suppressing vibration can be improved. As a result, the vibration caused by the driving of the motor 1 and the gear unit 5 can be suppressed from being transmitted to the inverter 8 , 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 the horizontal plane. The inverter 8 is fixed to the back surface of the top plate part 68a (that is, the surface facing the inner side of the inverter storage space 62). Thereby, the inverter cover 68 supports the inverter 8 .

According to this embodiment, the inverter 8 is fixed to the inverter cover 68 which can be detached from the casing main body 60 . Therefore, the inverter 8 can be easily detached from the motor unit 10 by releasing the fastening of the inverter cover 68 and the casing main body 60 during maintenance of the motor unit 10 such as periodic inspection and parts replacement. The above-described steps can also 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.

Moreover, the flow path for the refrigerant|coolant for cooling the inverter 8 may be provided in the top-plate part 68a. In this case, the flow path of the refrigerant is provided in the inverter cover 68 which is a different member from the casing main body 60 in contact with the motor 1 . According to the present 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. In addition, the flow path provided in the top-plate part 68a may be connected to the passage part (recess part 44) mentioned later. In this case, the refrigerant can be shared with the refrigerant that cools the inverter 8 and the refrigerant that cools the motor 1 .

(motor)

The motor 1 is a motor generator having both functions as an electric motor and functions 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 the inverter 8 . The inverter 8 converts a direct current supplied from a battery (not shown) into an alternating current and supplies it to the motor 1 . Each rotational speed of the motor 1 is controlled by controlling the inverter 8 .

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

The rotor 31 includes 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 the motor shaft 32 .

The rotor 31 (ie, the motor shaft 32, the rotor core 31a, and the rotor magnet) rotates around the motor axis J1. The torque of the rotor 31 is transmitted to the gear portion 5 . The rotor core portion 31a is formed by laminating silicon steel sheets. The rotor core 31a is a cylindrical body extending in the axial direction. A plurality of rotor magnets are fixed to the rotor core portion 31a. The plurality of rotor magnets are arranged in the circumferential direction with alternating magnetic poles.

The motor shaft 32 extends along a motor axis J1 extending in the width direction of the vehicle. The motor shaft 32 is a hollow shaft open to both sides in the axial direction of the motor axis J1. That is, the motor shaft 32 has the hollow part 32h opened to both sides in the axial direction.

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

The first end portion 32A of the motor shaft 32 is rotatably supported by the ball bearing 73 . A female spline 32b is provided at 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 splines 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 the 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 3 a 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 includes an annular stator core 35a, a coil 35b wound around the stator core 35a, and an insulator (not shown) sandwiched between the stator core 35a and the coil 35b . The stator core portion 35a has a plurality of pole teeth protruding radially inward of the motor axis J1. A coil wire is wound around the pole teeth. The coil wire wound around the pole teeth constitutes the coil 35b.

The coil 35b has coil side end portions 35c that protrude from the stator core portion 35a to both sides in the axial direction. One coil side end portion 35c protrudes in the axial direction from the axial end face of the stator core portion 35a, and the other coil side end portion 35c protrudes axially from the axial end face of the stator core portion 35a. The connecting coil wire 35d protrudes from the coil side end portion 35c on one side in the axial direction. The connection coil wire 35d has 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 connection coil wires 35d corresponding to each. 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 axial side (+Y side) of the motor 1 . The gear portion 5 transmits the power of the motor 1 and outputs it from the output shaft 55 . The gear portion 5 incorporates a plurality of mechanisms for power transmission between the drive source and the driven device.

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

Each gear and each shaft of the gear portion 5 are rotatable around either the motor axis J1 and 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 refers to the axial direction of the motor axis J1. That is, the axial direction in this specification refers to the direction parallel to the motor axis J1, that is, the vehicle width direction.

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

The input shaft 11 has: a first end 11A, which is located on one side in the axial direction (+Y side); and a second end 11B, which is located on the other side in the axial direction (+Y 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 11 a is provided on the outer peripheral surface of the second end portion 11B of the input shaft 11 . The male splines 11 a are fitted to the female splines 32 b 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 transmitting the rotation of the 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 about 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 different member attached to the outer peripheral surface of the input shaft 11 .

The layshaft 13 extends along the layshaft axis J3. The layshaft 13 rotates about the layshaft axis J3. The secondary shaft 13 has: a first end 13A, which is located on one side in the axial direction (+Y side); and a second end 13B, which is located on the other side in the axial direction ( -Y side).

The first end portion 13A of the counter shaft 13 is rotatably supported by the ball bearing 79 . The second end portion 13B of the counter shaft 13 is rotatably supported by the ball bearing 78 . A countershaft gear 23 and a drive gear 24 are provided on the outer peripheral surface of the countershaft 13 and 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 axial side (+Y side) of the counter gear.

The countershaft gear 23 rotates about the countershaft axis J3 together with the countershaft 13 . The counter gear 23 meshes with the input gear 21 .

The drive gear 24 rotates about the countershaft axis J3 together with the countershaft 13 and the countershaft 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 through the drive gear 24 to the differential device 50 .

The differential device 50 is arranged with the motor axis J1 as the center. That is, the differential gear 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 absorbing the speed difference of 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 gear 50 includes a gear housing 52 fixed to the ring gear 51 , a pair of pinion gears 53 a , a pinion shaft 53 b , and a pair of side gears 54 . The gear housing 52 rotates around the motor axis J1 together with the ring gear 51 .

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

The gear housing 52 is rotatably supported by tapered roller bearings 76 and 77 from both sides in the axial direction. 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 the 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 arranged in the axial direction. A pair of output shafts 55 are connected to the side gears 54 of the differential device 50 at each one end. That is, the output shaft 55 is connected to the ring gear 51 via the differential device 50 . The power of the motor 1 is transmitted to the output shaft 55 via each gear. In addition, a pair of output shafts 55 protrudes to the outside of the housing 6 at the other ends of each. A wheel H is attached to the other end of the output shaft 55 . The output shaft 55 transmits power to the outside (to the road surface via the wheels 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 disposed on the other side (−Y side) in the axial direction passes through the hollow portions 32 h and 11 h of the motor shaft 32 and the input shaft 11 . According to the motor unit 10 of the present embodiment, since a part of the output shaft 55 is arranged inside the motor shaft 32 and the input shaft 11 , the motor 1 and the differential device 50 can be arranged coaxially when viewed from the axial direction, and The size in the radial direction of the motor axis J1 of the motor unit 10 is miniaturized.

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 described above. 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 cage)

The stator holder 40 includes a cylindrical portion 41 that surrounds the stator 35 from the radially outer side, and a bottom plate portion 42 that extends from the other axial side (−Y side) of the cylindrical portion 41 . ) extends radially inward.

The stator holder 40 is arranged inside the cylindrical portion 60 a of the housing body 60 . The cylindrical portion 60a of the housing main body 60 has an inner peripheral surface 60aa facing radially inward. The opposing 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 41 b of the cylindrical portion 41 . Thereby, 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 part 41p is provided in the opening of the axial direction one side (+Y side) of the cylindrical part 41. As shown in FIG. The inner diameter of the fitting portion 41p is larger than the inner diameter of the region of the inner peripheral surface 41b in which the stator 35 is fitted. The first holder 81 of the shaft holding portion 80 is fitted into the fitting portion 41p.

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

The recessed portion 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 recessed portion 44 and the opposing inner peripheral surface 60aa. The refrigerant W cools the stator 35 via the stator holder 40 . The refrigerant W is cooled through a heat exchanger (not shown). Therefore, the stator holder 40 and the cylindrical portion 41 of the casing main body 60 function as a water jacket for cooling the stator 35 by surrounding the stator 35 and passing the refrigerant W therethrough.

In addition, in this embodiment, the case where the recessed part 44 is provided in the outer peripheral surface 41a of the cylindrical part 41, and the opening of the recessed part 44 is covered by the opposing inner peripheral surface 60aa is demonstrated. However, a concave portion may be provided on the opposing inner peripheral surface 60aa, and the opening of the concave portion may be covered by the outer peripheral surface 41a of the cylindrical portion 41 . In addition, the structure which passes the refrigerant|coolant W is not limited to this embodiment, You may provide the passage part which passes the refrigerant|coolant W between the outer peripheral surface 41a of the cylindrical part 41, and the opposing inner peripheral surface 60aa.

The outer peripheral surface 41a of the cylindrical portion 41 is provided with a pair of fitting portions 46 fitted into the opposing inner peripheral surface 60aa. 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 in the axial direction of the recessed portion 44 , and the other is located on the other side in the axial direction of the recessed portion 44 . According to the present embodiment, the stator holder 40 is fitted into the opposing inner peripheral surface 60aa of the housing main body 60 at the fitting portion 46 . Thereby, the positional accuracy of the stator holder 40 with respect to the radial direction of the housing main body 60 can be improved.

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

In addition, it is also possible to employ a configuration in which a groove for accommodating an O-ring compressed by the outer peripheral surface 41a of the cylindrical portion 41 is provided in the opposing inner peripheral surface 60aa. That is, the O-ring 45b serving as the sealing portion may be arranged between the outer peripheral surface 41a of the cylindrical portion 41 and the opposing inner peripheral surface 60aa, and may extend in the circumferential direction.

According to the present embodiment, the O-rings 45b are located on both sides in the axial direction of the recessed portion 44 serving as the passage portion of the refrigerant W, respectively. The O-ring 45b suppresses leakage of the refrigerant W from the recessed portion 44 to both sides in the axial direction. Furthermore, the oil O in the driving body housing space 61 can be suppressed from entering between the pair of O-rings 45b. Thereby, mixing of the oil O with the refrigerant W in the recessed portion 44 is suppressed.

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 42 a 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 protrudes from the edge portion of the insertion hole 42a to the axial direction 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 cage 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 dimensions of the stator holder 40 , and it is easy to improve the driving efficiency of the motor 1 .

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

The output shaft 55 protrudes from the opening on the other side (−Y side) in the axial direction of the motor shaft 32 . According to the present embodiment, the output shaft 55 and the motor shaft 32 are respectively supported by the ball bearings 71 and 72 arranged in line in the axial direction. One of the ball bearings 71 and 72 is held by the housing body 60 , and the other is held by the stator holder 40 . According to this embodiment, compared with the case where both ball bearings 71 and 72 are held in the case main body 60 , the structure of the case 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 arranged on the radially inner side of one coil side end portion 35 c located on the other side in the axial direction of the pair of coil side end portions 35 c 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 other side in the axial direction. Therefore, the ball bearing 72 that supports the second end portion 32B of the motor shaft 32 can be arranged at a position closer to the first end portion 32A. Thereby, the bearings 72 and 73 which support both end parts of the motor shaft 32 can be arranged close to each other, and the eccentricity of the motor shaft 32 and the like can be suppressed. Furthermore, the oil O dripped from the coil side end portion 35c can be supplied to the ball bearing 72 by cooling the coil side end portion 35c, 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 3 b in addition to the ball bearing 72 . The resolver stator 3 b is arranged inside the insertion hole 42 a and is positioned on the other side in the axial direction from 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 3a.

The resolver stator 3b and the resolver rotor 3a constitute a resolver. That is, the motor unit 10 includes the resolver 3 . The resolver 3 measures the rotational 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 can be disposed closer to the motor 1 than in the case where the housing body 60 supports the resolver stator 3b The location of the center of the axial dimension. Thereby, the resolver stator 3b can be suppressed from protruding in the axial direction with respect to the motor 1, and the axial dimension of the motor unit 10 can be reduced in size.

(shaft holding part)

The shaft holding portion 80 is arranged in the driver housing 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 retainer 81 , a second retainer 86 , ball bearings 73 , 74 , 75 , and 78 , and a tapered roller bearing 76 .

The first holder 81 is fixed to the stator holder 40 from one side in the axial direction (+Y side). Further, the second holder 86 is fixed to the first holder 81 from one side in the axial direction (+Y side). The ball bearings 73 , 74 , and 78 are held by the first retainer 81 . Further, the ball bearing 75 and the tapered 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 holder 81 has a main body disk portion 82 and a protruding disk portion 83 . The main body disc portion 82 and the protruding disc portion 83 are a single member connected to each other. The diameter of the outer shape of the main body disk portion 82 is larger than the diameter of the outer shape of the protruding disk portion 83 . The protruding disk portion 83 is offset from the main disk portion 82 in the radial direction and the axial direction (+Y side).

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 has a circular shape centered on the motor axis J1 when viewed in 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 the surface on one side (+Y side) in the axial direction of the main body disk portion 82 . 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 holder 86 is inserted into the screw hole 82s. That is, the second holder 86 is fixed by the plurality of fixing screws 84 inserted toward the other side (−Y side) in the axial direction with respect to the first holder 81 . Accordingly, the second holder 86 can be attached to the first holder 81 from the side of the first opening 61 a in the driver housing space 61 , so that the assembly process of the motor unit 10 can be simplified. Also, the plurality of fixing 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 protruding disk portion 83 has a disk shape centered on the counter 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 portion 13B of the secondary shaft 13 is arranged inside the second insertion hole 83h.

As shown in FIG. 1 , the main body disk portion 82 has an outer edge protruding portion 82 c that protrudes from the outer edge of the main body disk portion 82 to the other side (−Y side) in the axial direction. The outer edge protrusion 82c has a cylindrical shape centered on the motor axis J1. The outer peripheral surface of the outer edge protruding portion 82 c is fitted into the fitting portion 41 p of the stator holder 40 . Thereby, the first holder 81 is supported by the stator holder 40 . In addition, the first holder 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, 82b. The bearing holding parts 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 . 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 axial side of the motor 1 .

In the present embodiment, the motor 1 and the gear portion 5 are accommodated in the drive body accommodating space 61 which is integrally connected. Therefore, in the case where the shaft holding portion 80 is not provided, the motor shaft 32 becomes a cantilevered support, which may cause the eccentricity with the rotation to become conspicuous. 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 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 toward one side in the axial direction (+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 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 the surface of the protruding disk portion 83 facing toward one side in the axial direction (+Y side). The bearing holding portion 83 a supports the ball bearing 78 . The bearing holding portion 83 a 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 shafts on the motor axis J1 (the motor shaft 32 and the input shaft 11 ) but also the shafts on the counter axis J3 (the secondary shaft 13 ) rotatably . 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. In addition, the assembly process can be simplified by attaching the first retainer 81 to the housing main body 60 in a state where the plurality of bearings (ball bearings 73 and 78 ) are incorporated.

The axial positions of the ball bearing 73 and the ball bearing 78 may also overlap each other. In addition, the axial positions of the ball bearing 74 and the ball bearing 78 may also 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. As a result, the axial dimension of the shaft holding portion 80 can be reduced in size compared to the case where the bearings are staggered, and the drive body accommodating space 61 can be effectively used. In addition, among the plurality of bearings whose axial positions are overlapped, the oil O scattered in the radial direction can be supplied from one bearing to the other bearings, thereby improving the lubricity of the bearings.

As shown in FIG. 3 , the second holder 86 has a surrounding 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 has an annular shape surrounding the motor axis J1 from the radially outer side. The surrounding portion 88 includes a disk portion 88a and a surrounding cylindrical portion 88b extending from the outer edge of the disk 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 has a circular shape centered on the motor axis J1 when viewed in the axial direction. The output shaft 55 is arranged inside the third insertion hole 88h.

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

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

The second holder 86 is fixed to the first holder 81 so that the other axial side (−Y side) of the cutout portion 88 c is closed by the first holder 81 . Thereby, the notch part 88c functions as the opening part 87 which exposes the inside of the surrounding part 88 to the upper side.

The flange portion 89 is located at the end portion on the other side (−Y side) in the axial direction of the surrounding portion 88 . More specifically, the flange portion 89 extends radially outward from the end portion on the other side in the axial direction surrounding the cylindrical 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. In order to fix the second holder 86 to the first holder 81 , the fixing screw 84 inserted into the screw hole 82 s of the first holder 81 is inserted through 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 part 88f of the 2nd retainer 86 is provided in the surface which faces the axial direction other side (-Y side) of the disk part 88a. 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 which faces toward one side in the axial direction (+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 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 the 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 ensured according to the mounting accuracy of the second holder 86 with respect to the first holder 81 . Therefore, it is easy to improve the rotational efficiency of the motor shaft 32 and the input shaft 11 .

According to the present embodiment, the shaft holding portion 80 includes the surrounding portion 88 surrounding the motor axis, and the surrounding portion 88 is provided with the opening portion 87 that opens along the radial direction of the motor axis J1 . The opening portion 87 communicates the inside and outside of the surrounding portion 88 . Accordingly, the oil O scattered into the driving body storage space 61 by the lifting of the ring gear 51 or the like can reach the surrounding portion 88 , and the scattered oil O can be supplied to the inside of the surrounding portion 88 . In addition, the opening portion 87 of the present embodiment exposes the ball bearings 74 and 75 to the inside of the driver housing 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 the present embodiment, the opening portion 87 is opened upward. Therefore, the oil O that reaches the inside of the surrounding portion 88 from the opening portion 87 can be accumulated in the inside of the surrounding portion 88 . That is, the surrounding portion 88 has the oil storage space 64 in which the oil O is stored. In addition, the opening portion 87 and the oil storage space 64 are arranged 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 is opened in the oil storage space 64 . A part of the oil O in the oil storage space 64 penetrates into the hollow part 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 splines 11a and the female splines 32b of the connecting portion of the input shaft 11 and the motor shaft 32, thereby suppressing wear of the connecting portion. The oil O scatters from the connecting portion of the male spline 11 a and the female spline 32 b and is supplied to the ball bearing 73 supporting 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 storage space 64 . Therefore, the lower end portion of the input gear 21 is immersed in the oil O accumulated in the oil storage space 64 . The oil O is lifted up by the operation of the input gear 21 , diffused into the driving body storage space 61 , and spreads over the tooth surfaces of each gear.

In the present embodiment, the meshing portion 14 where the input gear 21 meshes with the counter gear 23 is arranged in the opening portion 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 has a plurality of bearing holding portions 82a, 82b, 88f, 88e, and 83a for holding the bearings, respectively. Among them, the bearing holding parts 82 a , 82 b , and 83 a are arranged on the first holder 81 , and the bearing holding parts 88 f and 88 e are arranged on the second holder 86 . In this way, since the first holder 81 and the second holder 86 that can be separated from each other each have the bearing holding portion, the first holder 81 and the second holder 86 can be respectively mounted in a state where the first holder 81 and the second holder 86 are separated. Simplified assembly process. Furthermore, the bearings can be attached from both sides in the axial direction of the first retainer 81 and the second retainer 86, respectively, so that the positional accuracy of the bearings in the axial direction and the radial direction can be improved.

(Inverter)

As shown in FIG. 1 , the inverter 8 is arranged in the inverter storage 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 direct current into 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 . Thereby, the front-rear direction dimension of the motor unit 10 can be reduced in size. This makes it possible to reduce the size of the motor unit 10 in the front-rear direction of the vehicle compared to the case where the inverter 8 is arranged in the front-rear direction of the vehicle with respect to the motor 1 . As a result, a large collision absorbing area (Japanese: クラッシャブルゾーン) in the vehicle can be ensured.

At least a portion of the inverter 8 overlaps the counter gear 23 when viewed in the axial direction. 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 is reduced, and the size of the motor unit 10 can be reduced.

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 has three inverters 8 corresponding to each.

Among the bus bars 9, the bus bar 9 has: an axially extending portion 9a extending in the axial direction; and a radially extending portion 9b extending in the radial direction of the motor axis J1 .

The end portion on the other side (−Y side) in the axial direction of the axially extending portion 9 a is connected to the inverter 8 . Further, an end portion on one axial side (+Y side) of the axially extending portion 9a is connected to the radially extending portion 9b. The radially extending portion 9b extends radially inward from the end portion of the axially extending portion, and is connected to the connecting coil wire 35d at the front end 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 9b.

The axially extending portion 9a passes through a through hole 60h provided in the partition wall 66 that partitions the driver housing space 61 and the inverter housing space 62 . Thereby, the bus bar 9 is arranged to span between the drive body storage space 61 and the inverter storage space 62 .

In addition, the bus bar 9 is held by a bus bar holder (not shown). The bus bar holder has a sealing structure which is arranged between the inner peripheral surface of the through hole 60h and the bus bar 9 to seal between the driver housing space 61 and the inverter housing space 62 . Thereby, the bus bar holder suppresses the intrusion of the oil O in the drive body storage space 61 into the inverter storage space 62 .

According to this 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 between the inverter 8 and the gear portion 5 . In addition, the through hole 60h penetrates the side wall portion 60db in the axial direction. As described above, the driver housing space 61 is opened to the axial direction side (+Y side) at the first opening portion 61a. The bus bar 9 is accommodated in the driver housing space 61 from the first opening 61 a and inserted into the through hole 60 h, so that the bus bar 9 can be attached to the case main body 60 . According to the present embodiment, the bus bar 9 can be attached to the case main body 60 from the first opening 61a similarly to other members, and the assembly process can be simplified by attaching from one direction.

＜Oil circuit＞

The oil passage 90 is a passage of the oil O that circulates the oil O in the casing 6 . The oil passage 90 is provided in the casing 6 . An oil pump 96 is provided in the oil passage 90 .

In addition, in this specification, the concept of an "oil passage" includes not only a "flow passage" that forms a stable flow of oil in one direction at all times, but also a passage (for example, the oil storage space 63 ) where the oil supply temporarily stays, and the oil supply. The path of oil dripping.

The oil passage 90 has a first flow passage 91 that guides the oil O from the oil storage space 63 to the oil pump 96 , and a second flow passage 97 that travels from the oil pump 96 toward the motor 1 The upper side extends and supplies 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 storage space 63 to the oil pump 96 . 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 side end portions 35 c of the stator 35 .

The oil pump 96 is located on the other side (−Y side) in the axial direction of the motor 1 . 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 the oil O from the oil storage space 63 and presses 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 96 a , an external gear 92 and an internal gear 93 .

The pump casing 96a is fixed to the bottom 60b of the casing main body 60 . In the present embodiment, the pump housing 96a has a circular shape when viewed in the axial direction. A pump chamber 96c, a suction port 94, and a discharge port 95 are provided in the pump case 96a.

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

The suction port 94 and the discharge port 95 are open to 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 the oil O from the suction port 94 and discharges the oil O from the discharge port 95 .

The externally toothed gear 92 is a gear rotatable about the motor axis J1. The externally toothed gear 92 is fixed to the output shaft 55 . The externally toothed gear 92 is accommodated in the pump chamber 96c. The externally toothed gear 92 has a plurality of tooth portions 92a on the outer peripheral surface. The tooth profile of the tooth portion 92a of the externally toothed gear 92 is a trochoidal tooth profile.

The internally toothed gear 93 is an annular gear rotatable about an axis J2 that is eccentric with respect to the motor axis J1. The outer diameter of the internally toothed gear is slightly smaller than the inner diameter of the pump chamber 96c. The outer peripheral surface of the internally toothed gear 93 is slidably opposed to the inner peripheral surface of the pump chamber 96c.

The internally toothed gear 93 surrounds the radially outer side of the externally toothed gear 92 and meshes with the externally toothed gear 92 . The internally toothed gear 93 has a plurality of tooth portions 93a on the inner peripheral surface. The tooth profile of the tooth portion 93a of the internally toothed gear 93 is a trochoidal tooth profile.

By the rotation of the external gear 92 around the motor axis J1, the external gear 92 and the internal gear 93 meshing with the external gear 92 are also rotated around the axis J2. Thereby, the gap between the tooth portion 92 a of the externally toothed gear 92 and the tooth portion 93 a of the internally toothed 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 it 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 via the second flow paths 97, respectively. The oil O supplied to the coil side ends 35c permeates the entire coil 35b under the action of capillary force and gravity acting between the coil wires, while taking heat from the stator 35. Next, the oil O drips downward, and returns to the oil storage space 63 through the hole provided in the stator holder 40 , the communication hole 65 , and the like.

According to the present embodiment, since the stator core portion 35a is cooled by the refrigerant W via the stator holder 40, and the coil side end portion 35c is directly cooled by the oil O, 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 . The motor 1 is arranged just above the oil storage space 63 , and a passage portion (recess 44 ) for the refrigerant W is provided around the motor 1 . 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 side end portion 35c in a state where the temperature is lowered, and the coil side end portion 35c can be efficiently cooled.

(Manufacturing method of motor unit)

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

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

<The first process>

The first step is an output shaft attaching step of attaching the output shaft 55 to the casing body 60 . Before the first step, the bottom cover member 69 is attached to the case main body 60 in advance. Thereby, the bottom cover member 69 covers the third opening 63a of the case 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 on the bottom portion 60b of the housing main body 60 . Next, the output shaft 55 is accommodated in the drive body accommodating space 61 from the first opening 61 a of the casing main body 60 . Next, the output shaft 55 is attached to the housing main body 60 by inserting the end portion 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 attached to the output shaft 55 .

<Second process>

The second step is a motor mounting step of mounting the motor 1 to the housing body 60 . Before the second process, the rotor 31 and the stator 35 are respectively assembled in advance. Furthermore, the stator 35 is previously attached to 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 driver accommodation space 61 from the first opening 61a. Then, the fitting portion 46 of the stator holder 40 is fitted into the opposing inner peripheral 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 casing main body 60 .

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

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

<The third process>

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

<The fourth step>

The fourth step is a step of attaching the first cage 81 to the stator holder 40 . Before the fourth step, the ball bearing 73 and the ball bearing 78 are attached to the first cage 81 in advance.

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

<The fifth process>

The fifth step is a step of attaching the input shaft 11 , the counter shaft 13 , the input gear 21 , the counter shaft 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 shaft gear 23 , and the drive gear 24 are accommodated in the drive body accommodation space 61 from the first opening 61 a of the housing body 60 and mounted.

<The sixth process>

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 previously attached to the second cage 86 .

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

By going through the mounting steps of the first holder 81 and the second holder 86 in the fourth step and the sixth step, the shaft holder 80 is accommodated in the drive body accommodating space 61 from the first opening 61 a of the housing main body 60 and to be fixed.

<The seventh process>

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

The fifth step and the seventh step described above are the gear unit mounting steps of accommodating and fixing the gear unit 5 in the driver housing space 61 from the first opening 61a.

<The eighth process>

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

In the eighth step, first, the first opening portion 61 a of the casing main body 60 is covered by the closing member 67 , and is attached and fastened. At the same time, the countershaft 13 is inserted into the ball bearing 79 and the gear housing 52 is held on the tapered roller bearing 77 .

The above-described first to eighth steps are steps of attaching each member including the motor 1 and the gear portion 5 to the drive body accommodating space 61 of the housing main body 60 . In the first step to the eighth step, each member is attached to the housing body 60 from one side in the axial direction (+Y side). According to the present 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 to manufacture the motor unit 10 can be shortened.

<Ninth process>

The ninth step is a step of attaching the inverter 8 to the casing body 60 . Before the ninth step, the inverter 8 is attached to the inverter cover 68 in advance. 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 casing body 60 . As a result, the inverter 8 is arranged in the inverter storage space 62 , and the second opening 62 a of the casing main body 60 is covered by the inverter cover 68 . Next, the window (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 housing space 62 , and the window is closed again.

As described above, in the first to eighth steps, each member is attached to the case body 60 from the opening direction of the first opening portion 61a. On the other hand, in the ninth step, the inverter 8 and the inverter cover 68 are attached to the casing body 60 from the opening direction of the second opening portion 62a. Therefore, the assembly posture of the case main body 60 is changed before the ninth process is performed. In the present embodiment, the steps of attaching the motor 1 and the gear portion 5 (the first step to the eighth step) are performed with the first opening facing upward. In addition, the process (ninth process) of mounting the inverter 8 is performed in the state which made the 2nd opening part 62a face upward. Thereby, the assembling work can be facilitated.

The embodiments of the present invention and their modifications have been described above, but the respective structures and their combinations in the embodiments and modifications are examples, and additions, omissions, and substitutions of structures can be made without departing from the spirit of the present invention. and other changes. Furthermore, the present invention is not limited by the embodiments.

(Symbol Description)

1 motor; 3 resolver; 3a resolver rotor; 3b resolver stator; 5 gear part; 6 housing; 8 inverter; 9 busbar; 10 motor unit; 11 input shaft; 13 counter shaft; 14 meshing part; 21 input Gear; 23 countershaft gear; 31 rotor; 32 motor shaft; 35 stator; 35a stator core; 35b coil; 35c coil side end; 40 stator cage; 41 cylindrical part; 42 Bottom plate part; 43 Bearing holding part; 44 Recessed part (passage part); 45b O-ring (seal part); 46 Fitting part; 50 Differential gear; 51 Ring gear; 55 Output shaft; Inner peripheral surface; 60b bottom; 60ba bearing holding part; 60da box bottom (partition wall); 60db side wall part (partition wall, first wall part); 60h through hole; 61 driver storage space; 61a first opening part; 62 reverse Inverter storage space; 62a second opening; 63 oil storage space; 63a third opening; 64 oil storage space; 66 partition; 68 inverter cover; 71 ball bearing; 72 ball bearing; 73 ball bearing (first bearing); 74 ball bearing (fifth bearing); 75 ball bearing (second bearing); 76 tapered roller bearing (fourth bearing); 77 tapered roller bearing; 78 ball bearing (third bearing); 79 ball bearing 80 shaft holding part; 81 first holder; 82a bearing holding part (first bearing holding part); 82b bearing holding part; 83a bearing holding part; 84 fixing screw; 86 second holder; 87 opening part; 88 surrounding 88e bearing holding part (third bearing holding part); 88f bearing holding part (second bearing holding part); J1 motor axis; J2 axis; J3 countershaft axis; O oil; W refrigerant.

Claims (7)

1. A motor unit, comprising: a motor having a motor shaft extending along the motor axis; a gear part, the gear part is connected to one axial side of the motor; a shaft holding portion located between the motor and the gear portion in the axial direction; and a housing main body, the housing main body is provided with a drive body storage space, and the drive body storage space accommodates the motor, the gear part, and the shaft holding part, The motor shaft is a hollow shaft, The gear part has: an output shaft, a part of which is disposed inside the motor shaft, and the output shaft rotates around the motor axis; and a plurality of gears that transmit power from the motor shaft to the output shaft, The shaft holding part has: a first bearing that rotatably supports the motor shaft; a first retainer that retains the first bearing; a second bearing that rotatably supports the output shaft; and A second holder is fixed to the first holder from one side in the axial direction, and holds the second bearing. 2. The motor unit of claim 1, wherein, The shaft holding portion has an annular surrounding portion that surrounds the motor axis from the radially outer side, An opening is provided in the surrounding portion, and the opening is opened in the radial direction of the motor axis, The gear part has: an input gear connected to the motor shaft and rotating about the motor axis; and a countershaft gear that meshes with the input gear and rotates about a countershaft axis extending parallel to the motor axis, A meshing portion where the counter gear meshes with the input gear is arranged in the opening portion. 3. The motor unit of claim 2, wherein, The gear part has a countershaft, the countershaft extends along the axis of the countershaft, and the countershaft gear is provided on the outer peripheral surface, The said shaft holding|maintenance part has the 3rd bearing which is hold|maintained by the said 1st holder, and rotatably supports the said countershaft. 4. A motor unit as claimed in claim 2 or 3, wherein, The gear portion has an input shaft, the input shaft is connected to the motor shaft in the axial direction, and the input gear is provided on the outer peripheral surface, The shaft holding portion has a fifth bearing that rotatably supports the input shaft in the first holder. 5. The motor unit of any one of claims 1 to 4, wherein, The second holder has a cylindrical second bearing holding portion that surrounds the second bearing from the radially outer side. 6. The motor unit of any one of claims 1 to 5, wherein, the second holder is fixed by a plurality of fixing screws inserted in the axial direction with respect to the first holder, A plurality of the fixing screws are arranged along the circumference of the motor axis. 7. The motor unit of any one of claims 1 to 6, wherein, The gear portion has a differential device that transmits power to the output shaft, The differential has a ring gear that rotates around the motor axis, The second retainer of the shaft holding portion includes a fourth bearing holding portion that holds a fourth bearing that supports the ring gear.

Images