CN112840535A

CN112840535A - Motor unit

Info

Publication number: CN112840535A
Application number: CN201980062960.1A
Authority: CN
Inventors: 村田大辅; 水谷真澄; 福永庆介
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2018-09-28
Filing date: 2019-09-26
Publication date: 2021-05-25
Anticipated expiration: 2039-09-26
Also published as: JPWO2020067277A1; CN112840535B; WO2020067277A1; JP7389045B2

Abstract

One embodiment of the present invention is a motor unit mounted on a vehicle to drive the vehicle. The motor unit has: a main body part having a motor and a housing for housing the motor; and an inverter unit having an inverter that supplies power to the motor and an inverter case that houses the inverter. The main body portion has a 1 st bus bar connected to a coil of the motor. The inverter unit has a 2 nd bus bar connected to the inverter, the 2 nd bus bar being connected to the 1 st bus bar at a connection portion. The 1 st bus bar has: a terminal connection portion connected to the coil at an end portion on one side in an axial direction of the motor; a radial extension portion extending from the terminal connection portion to a radial outside of the motor; and an axial extension portion that extends in the axial direction of the motor along the outer side surface of the motor from a radially outer end portion of the radial extension portion. The 1 st bus bar has a plate shape with the radial direction of the motor as the plate thickness direction in the axial extension portion.

Description

Motor unit

Technical Field

The present invention relates to a motor unit. The application is based on Japanese laid-open application No. 2018-185590, which is proposed by 9/28.2018. This application claims priority to this application. The contents of which are incorporated by reference in their entirety in this application.

Background

In recent years, the development of a drive device mounted on an electric vehicle has been actively carried out. Patent document 1 describes a motor unit connected to a PDU (power drive unit) having an inverter.

Documents of the prior art

Patent document

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

Disclosure of Invention

Problems to be solved by the invention

The motor and the inverter are connected to each other via a conductive member called a bus bar. The bus bars are connected to the motor and the inverter, respectively, and are connected to each other at a final stage of the assembly process. In the conventional structure, workability when the bus bars are connected to each other is problematic.

In view of the above, an object of the present invention is to provide a motor unit that can facilitate a connection process between bus bars connected to a motor and an inverter, respectively.

Means for solving the problems

One aspect of the present invention is a motor unit mounted on a vehicle to drive the vehicle. The motor unit has: a main body part having a motor and a housing accommodating the motor; and an inverter unit having an inverter that supplies power to the motor and an inverter case that houses the inverter. The main body portion has a 1 st bus bar connected to a coil of the motor. The inverter unit has a 2 nd bus bar connected to the inverter, the 2 nd bus bar being connected to the 1 st bus bar at a connection portion. The 1 st bus bar has: a terminal connection portion connected to the coil at an end portion on one side in an axial direction of the motor; a radially extending portion that extends from the terminal connecting portion to a radially outer side of the motor; and an axial extension portion that extends in the axial direction of the motor along an outer side surface of the motor from a radially outer end portion of the radial extension portion. The 1 st bus bar has a plate shape in which a plate thickness direction is set in a radial direction of the motor in the axially extending portion.

Effects of the invention

According to one aspect of the present invention, there is provided a motor unit capable of facilitating a process of connecting bus bars connected to a motor and an inverter, respectively.

Drawings

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

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

Fig. 3 is an exploded perspective view of a motor unit according to an embodiment.

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

Fig. 5 is a perspective view of the motor unit according to the embodiment, with a housing omitted.

Detailed Description

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

In the following description, the direction of gravity is defined based on the positional relationship when the motor unit 10 is mounted on a vehicle on a horizontal road surface. In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the vertical direction), + Z direction is the upper side (the opposite side to the direction of gravity), and-Z direction is the lower side (the direction of gravity). The X-axis direction is a direction perpendicular to the Z-axis direction, and indicates the front-rear direction of the vehicle on which the motor unit 10 is mounted, + X direction is the front of the vehicle, and-X direction is the rear of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and indicates the width direction (left-right direction) of the vehicle, + Y direction is the left direction of the vehicle, and-Y direction is the right direction of the vehicle.

In the following description, each direction will be described centering on the motor axis J1 of the motor 1. That is, the axial direction of the motor 1 about the motor axis J1 is simply referred to as the "axial direction", the radial direction of the motor 1 about the motor axis J1 is simply referred to as the "radial direction", and the circumferential direction of the motor 1 about the motor axis J1 is simply referred to as the "circumferential direction".

Fig. 1 is a conceptual diagram of a motor unit 10 according to an embodiment. Fig. 2 is a perspective view of the motor unit 10.

The motor axis J1, the sub axis J3, the output axis J4, and the rotation axis J6, which will be described later, are imaginary axes that do not actually exist.

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

As shown in fig. 1, the motor unit 10 has a main body portion 9 and an inverter unit 8. The main body 9 includes a motor 1, a transmission mechanism (transaxle) 5, and a case 6 that houses the motor 1 and the transmission mechanism 5.

(case)

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

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

(Motor)

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

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

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

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

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

(transfer mechanism)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(inverter unit)

As shown in fig. 2, the inverter unit 8 has an inverter 8a and an inverter case 8b that houses the inverter 8 a. The inverter 8a supplies electric power to the motor 1. Although not shown, the inverter unit 8 further includes a circuit board and a capacitor.

Fig. 3 and 4 are exploded perspective views of the motor unit 10, and are views of separating the inverter unit 8 from the main body 9. In fig. 3 and 4, the motor unit 10 is different from each other in the perspective view direction.

The inverter unit 8 has a substantially rectangular shape when viewed in the vertical direction. The inverter unit 8 is fixed to the upper surface 6a of the case 6. More specifically, the inverter unit 8 is fixed to the upper surface 6a of the motor housing 62 of the case 6 in the inverter case 8 b. Further, a notch surface cut along the lower surface of the inverter unit 8 is provided substantially at the center of the upper surface 6 a. The upper surface 6a is vertically opposed to the lower surface of the inverter unit 8 with a gap therebetween in the cutout surface. This can suppress the transmission of vibration of the case 6 to the inverter unit 8 and the excitation of the inverter unit 8.

In the present specification, the upper surface 6a of the housing 6 refers to the entire surface of the outer surface of the housing 6 facing upward. The case 6 is opposed to the lower surface of the inverter unit 8 at the upper surface 6 a.

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

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

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

As shown in fig. 3 and 4, the inverter unit 8 is fixed to the housing 6 of the motor unit 10 in the plurality of fixing portions 40, 45. The plurality of fixing portions 40 and 45 are classified into a 1 st fixing portion 40 (see fig. 3) and a 2 nd fixing portion 45 (see fig. 4). The 1 st fixing portion 40 is located on the vehicle front side with respect to the motor axis J1, and the 2 nd fixing portion 45 is located on the vehicle rear side with respect to the motor axis J1.

As shown in fig. 3, the 1 st fixing portion 40 includes a brim 42 provided in the inverter unit 8, an opposite surface 43 provided in the case 6, and a fixing bolt 41.

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

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

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

As shown in fig. 4, the 2 nd fixing portion 45 includes a brim portion 47 provided on the case 6, an opposite surface 48 provided on the inverter unit 8, and a fixing bolt 46.

The eaves 47 of the 2 nd fixing portion 45 protrude in the horizontal direction at the outer side surface of the motor housing portion 62 of the case 6. The brim 47 is provided with a through hole 47a penetrating in the vertical direction.

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

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

The 1 st fixing portion 40 and the 2 nd fixing portion 45 are disposed on opposite sides of the motor axis J1 as viewed in the vertical direction. Moreover, the eaves 42 and 47 of the 1 st and 2 nd fixing portions 40 and 45 protrude in directions away from the motor axis J1, respectively, when viewed in the vertical direction.

According to the present embodiment, the eaves 42 and 47 of the 1 st and 2 nd fixing portions 40 and 45, which are located on opposite sides of the motor axis J1, are provided separately to the inverter unit 8 and the case 6, respectively. Therefore, the dimension of the motor unit 10 in the vehicle longitudinal direction can be reduced as compared with a case where all the eaves are provided on either one of the inverter unit 8 and the case 6.

(connection Structure of Motor and inverter)

Next, an electrical connection structure between the motor 1 and the inverter 8a will be described. The motor 1 and the inverter 8a are connected via bus bars 71, 72.

Fig. 5 is a perspective view of the motor unit 10 with the illustration of the housing 6 omitted.

The main body 9 has 31 st bus bars 71 and 1 st bus bar holders 76. In fig. 5, the 1 st bus bar holder 76 is shown by a broken line. On the other hand, the inverter unit 8 has 32 nd bus bars 72, and a 2 nd bus bar holder 77.

The 1 st bus bar 71 and the 2 nd bus bar 72 have a plate shape. The 1 st bus bar 71 is connected to the coil 32a of the motor 1. On the other hand, the 2 nd bus bar 72 is connected to the inverter 8 a. The 1 st bus bar 71 and the 2 nd bus bar 72 are connected to each other at a connection portion 79. The connecting portion 79 is located inside the housing 6. The motor 1 and the inverter 8a are electrically connected via the 1 st bus bar 71 and the 2 nd bus bar 72.

The 1 st bus bar 71 is held by the 1 st bus bar holder 76. The 31 st bus bars 71 are embedded in the 1 st bus bar holder 76 by insert molding. The 1 st bus bar 71 and the 1 st bus bar holder 76 are disposed in a motor chamber 6A (see fig. 1) inside the housing 6.

The 1 st bus bar 71 has a terminal connecting portion 71a, a radially extending portion 71b, an axially extending portion 71c, and a circumferentially extending portion 71 d.

The terminal connecting portion 71a is located on one axial side (+ Y side) of the motor 1. The terminal connection portion 71a is connected to the coil 32a of the motor 1. The coil 32a has a pair of coil ends 32b projecting from the stator core to one axial side. A coil end 32c, to which the lead wires corresponding to the U-phase, the V-phase, and the W are bundled, extends from one coil end 32b in the axial direction out of the pair of coil ends 32 b. A crimp terminal is attached to the tip of the coil end 32 c.

The terminal connecting portion 71a is connected to the crimp terminal of the coil end 32 c. That is, the terminal connection portion 71a is connected to the coil 32a at one axial end of the motor 1. The terminal connection portion 71a and the crimp terminal of the coil end 32c are fastened by a screw 78.

The terminal connecting portion 71a extends in the axial direction. The coil end 32c extends from the coil end 32b to one axial side. Since the terminal connection portion 71a extends in the axial direction, the coil end 32c does not need to be bent when the coil end 32c and the terminal connection portion 71a are connected. Therefore, the process of connecting the coil end 32c and the terminal connecting portion 71a is facilitated. In addition, in a state where the coil end 32c is connected to the terminal connection portion 71a, it is possible to suppress application of a load to the coil end 32 c.

The 1 st bus bar 71 is in the terminal connecting portion 71a with the radial direction as the plate thickness direction. More specifically, the thickness direction is a direction parallel to a direction perpendicular to the tangential direction. Therefore, the terminal connecting portion 71a can be made to extend along the coil end 32c from the radial outside. This facilitates the connection process between the coil end 32c and the terminal connection portion 71 a.

The terminal connecting portions 71a of the 31 st bus bars 71 are arranged in the circumferential direction. Therefore, the 3 terminal connecting portions 71a do not overlap each other when viewed in the radial direction. Therefore, the work of connecting the terminal connecting portion 71a and the coil end 32c from the radially outer side can be simplified.

The radially extending portion 71b is located on one axial side of the motor 1. The radially extending portion 71b extends radially outward from the terminal connecting portion 71 a. That is, the radially extending portion 71b is connected to the terminal connecting portion 71 a. The 1 st bus bar 71 is bent in the plate thickness direction at the boundary between the terminal connecting portion 71a and the radially extending portion 71 b. The radially outer end of the radially extending portion 71b is located radially outward of the stator 32 as viewed in the axial direction.

The 1 st bus bar 71 is formed in the radially extending portion 71b in the plate thickness direction in the axial direction. Therefore, the dimension of the radial extension portion 71b in the axial direction can be reduced. As a result, the dimension of the region of the motor chamber 6A of the housing 6 that houses the radially extending portion 71b along the axial direction can be reduced, and the housing 6 can be reduced in size.

The axially extending portion 71c extends in the axial direction along the outer side surface of the motor 1 from the radially outer end of the radially extending portion 71 b. The axially extending portion 71c is located radially outward of the stator 32. In addition, the axial position of the axially extending portion 71c overlaps the axial position of the stator 32.

The axially extending portion 71c has a 1 st end portion 71ca on one side in the axial direction and a 2 nd end portion 71cb on the opposite side (i.e., the other side in the axial direction) of the 1 st end portion 71 ca. The axially extending portion 71c is connected to the radially extending portion 71b at the 1 st end 71 ca. The 1 st bus bar 71 is bent in the plate thickness direction at the boundary between the radially extending portion 71b and the axially extending portion 71 c.

The 1 st bus bar 71 is in the plate thickness direction in the radial direction in the axially extending portion 71 c. Therefore, the dimension of the axial extension portion 71c in the radial direction can be reduced. As a result, the dimension of the region of the motor chamber 6A of the housing 6 that houses the axially extending portion 71c along the radial direction can be reduced, and the housing 6 can be reduced in size.

The circumferentially extending portion 71d extends in the circumferential direction from the 2 nd end portion 71cb of the axially extending portion 71 c. In the present embodiment, the circumferentially extending portion 71d extends upward (i.e., in a direction toward the inverter unit 8) from the axially extending portion 71 c. The 1 st bus bar 71 is in the plate thickness direction in the radial direction in the circumferentially extending portion 71 d. The plate thickness direction of the circumferentially extending portion 71d coincides with the plate thickness direction of the axially extending portion 71 c. The 1 st bus bar 71 is bent in a direction perpendicular to the plate thickness direction at a boundary portion between the circumferentially extending portion 71d and the axially extending portion 71 c.

The circumferentially extending portion 71d has a 1 st connecting end 71da located on the opposite side of the axially extending portion 71 c. The 1 st bus bar 71 is connected to the 2 nd bus bar 72 at the 1 st connection end 71da of the circumferentially extending portion 71 d. That is, the connecting portion 79 is located at the circumferentially extending portion 71 d. The 1 st connection ends 71da of the 31 st bus bars 71 are arranged in the axial direction.

According to the present embodiment, the 1 st bus bar 71 has the terminal connecting portion 71a, the radially extending portion 71b, and the axially extending portion 71 c. The 1 st bus bar 71 is routed from one side in the axial direction of the motor 1 to a position along the outer side surface of the motor 1. This allows the 1 st bus bar 71 to be routed to the vicinity of the inverter unit 8 disposed around the motor 1. As a result, the 1 st bus bar 71 and the 2 nd bus bar 72 can be easily connected.

According to the present embodiment, since the 1 st bus bar 71 has the circumferentially extending portion 71d, the 1 st connection end 71da connected to the 2 nd bus bar 72 can be arranged on one circumferential side. That is, according to the present embodiment, the 1 st connection end 71da of the 1 st bus bar 71 can be disposed close to the inverter unit 8. As described later, the 2 nd bus bar 72 is protrudingly extended from the lower surface of the inverter case 8 b. By disposing the 1 st connection end 71da of the 1 st bus bar 71 close to the inverter unit 8, the projecting length of the 2 nd bus bar 72 can be shortened. If the projecting length of the 2 nd bus bar 72 is too long, the 2 nd bus bar 72 may interfere with other members and be deformed in the assembly process of the inverter unit 8 and the main body portion 9. According to the present embodiment, the protruding length of the 2 nd bus bar 72 can be shortened, thereby facilitating handling of the bus bar unit in the assembly process.

The 32 nd bus bars 72 are held by the 2 nd bus bar holder 77. The 2 nd bus bar holder 77 has a rectangular shape with its corners bent in the longitudinal direction when viewed in the axial direction. The 2 nd bus bar holder 77 is provided with through holes (not shown) that penetrate in the vertical direction and into which the 2 nd bus bars 72 are inserted. The lower end (the 2 nd connection end 72b) of the 2 nd bus bar holder 77 protrudes and is exposed from the 2 nd bus bar holder 77.

A seal (not shown) is provided on the outer peripheral surface of the 2 nd bus bar holder 77 facing in the horizontal direction. As described later, the 2 nd bus bar holder 77 is inserted into the opening hole 6h provided on the housing 6. The seal suppresses the penetration of moisture between the outer peripheral surface of the 2 nd bus bar holder 77 and the inner peripheral surface of the open hole 6 h.

The 2 nd bus bar 72 protrudes downward from the lower surface of the inverter case 8 b. The 2 nd bus bar 72 extends to the inside of the housing 6, and is connected to the 1 st bus bar 71 at a connection portion 79. The 2 nd bus bar 72 has a plate shape. The 2 nd bus bar 72 is in the plate thickness direction in the radial direction. The thickness direction of the 2 nd bus bar 72 coincides with the thickness direction of the circumferentially extending portion 71d of the 1 st bus bar 71. The 32 nd bus bars 72 are arranged in the axial direction.

A 2 nd connection end 72b is provided at a lower end portion of the 2 nd bus bar 72. The 2 nd bus bar 72 is connected to the 1 st bus bar 71 at a 2 nd connection end 72 b. The 32 nd link ends 72b are arranged in the axial direction.

The connecting portion 79 has 3 connecting bolts 79 a. The 1 st connection end 71da of the 1 st bus bar 71 and the 2 nd connection end 72b of the 2 nd bus bar 72 are fixed to each other at the connection portion 79 by a connection bolt 79 a. A cross-shaped groove is provided in the head of the connecting bolt 79 a. The connecting bolt 79a is rotated by a tool (e.g., a phillips screwdriver) to fasten the 1 st bus bar 71 and the 2 nd bus bar 72.

As shown in fig. 3, an opening hole 6h for communicating the inside and outside of the case 6 is provided in the upper surface 6a of the case 6. The opening hole 6h penetrates the outer side surface of the housing 6 in the vertical direction and is open at the upper side.

The 32 nd bus bars 72 and the 2 nd bus bar holder 77 are inserted into the opening hole 6h of the housing 6. The 2 nd bus bar holder 77 protrudes from the lower surface of the inverter unit 8 and extends to the inside of the case 6.

A window portion 6w that communicates the inside and the outside of the housing 6 is provided on the outer surface of the housing 6 facing the radial direction. The window portion 6w penetrates the motor housing portion 62 of the housing 6 in the radial direction, and is open in the radial direction. The window portion 6w is located immediately below the opening hole 6 h. That is, the axial position of the window portion 6w overlaps the axial position of the opening hole 6 h. The opening direction of the window portion 6w is perpendicular to the opening direction of the opening hole 6 h. The window portion 6w is located radially outward of the connection portion 79. The window portion 6w overlaps the connection portion 79 as viewed in the radial direction. Therefore, the window portion 6w exposes the connection portion 79.

The window portion 6w is covered with a cover member 6 c. That is, the housing 6 has a cover member 6c that covers the window portion 6 w. The cover member 6c is screwed to the outer surface of the housing 6 using screws not shown. The lid member 6c has a plate shape in which the opening direction of the window portion 6w is the plate thickness direction.

According to the present embodiment, a window portion 6w that exposes the connection portion 79 is provided on the outer surface of the housing 6. Therefore, the operator can insert a tool (a phillips screwdriver in the present embodiment) into the housing 6 through the window 6w to connect the 1 st bus bar 71 and the 2 nd bus bar 72 to each other at the connection portion 79. That is, according to the present embodiment, the connection step of the 1 st bus bar 71 and the 2 nd bus bar 72 can be easily performed.

According to the present embodiment, the window portion 6w is opened in the radial direction on the outer side surface of the housing 6. Therefore, the window portion 6w can be disposed close to the connection portion 79. As a result, the approach from the window portion 6w to the connection portion 79 can be facilitated, and the work of connecting the 1 st bus bar 71 and the 2 nd bus bar 72 by the operator can be facilitated.

According to the present embodiment, the 1 st bus bar 71 and the 2 nd bus bar 72 extend in the circumferential direction along the outer side surface of the motor 1 at the connection portion 79. As a result, the connection portion 79 can be disposed close to the window portion 6w that is open in the radial direction, and the access from the window portion 6w to the connection portion 79 can be facilitated.

According to the present embodiment, the plate thickness direction of the connection portion 79 of the 1 st bus bar 71 and the 2 nd bus bar 72 coincides with the opening direction of the window portion 6 w. Therefore, when the 1 st bus bar 71 and the 2 nd bus bar 72 are fastened and fixed to each other from the plate thickness direction, the fixing work of the 1 st bus bar 71 and the 2 nd bus bar 72 can be facilitated. More specifically, in the present embodiment, the connection bolt 79a of the connection portion 79 extends along the opening direction of the window portion 6 w. Therefore, the operator can easily fasten the 1 st bus bar 71 and the 2 nd bus bar 72 by inserting a tool through the window portion 6 w.

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

For example, in the present embodiment, a case where the 1 st bus bar is constituted by a single member is described. However, the 1 st bus bar may be constituted by a plurality of members. As an example, the 1 st bus bar may have a structure in which the 1 st member having the terminal connecting portion, the radially extending portion, and the axially extending portion 71c and the 2 nd member having the circumferentially extending portion 71d are connected to each other, and the 1 st member and the 2 nd member may be adopted.

Description of the reference symbols

1: a motor; 5: a transfer mechanism; 6: a housing; 6 a: an upper surface; 6 c: a cover member; 6 h: an open pore; 6 w: a window portion; 8: an inverter unit; 8 a: an inverter; 8 b: an inverter case; 9: a main body portion; 10: a motor unit; 11: a motor drive shaft; 13: a counter shaft; 21: a motor driving gear; 23: a counter gear; 24: a drive gear; 32 a: a coil; 51: a ring gear; 55: an output shaft; 71: 1 st bus bar; 71 a: a terminal connecting portion; 71 b: a radial extension; 71 c: an axial extension; 71 ca: 1 st end part; 71 cb: a 2 nd end portion; 71 d: a circumferential extension; 72: a 2 nd bus bar; 79: a connecting portion; 79 a: a connecting bolt; j1: a motor axis; j3: a minor axis; j4: an output axis.

Claims

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

the motor unit includes:

a main body part having a motor and a housing accommodating the motor; and

an inverter unit having an inverter that supplies power to the motor and an inverter case that houses the inverter,

the main body portion has a 1 st bus bar connected to a coil of the motor,

the inverter unit has a 2 nd bus bar connected to the inverter, the 2 nd bus bar being connected to the 1 st bus bar at a connection portion,

the 1 st bus bar has:

a terminal connection portion connected to the coil at an end portion on one side in an axial direction of the motor;

a radially extending portion that extends from the terminal connecting portion to a radially outer side of the motor; and

an axial extension portion that extends in an axial direction of the motor along an outer side surface of the motor from a radially outer end portion of the radial extension portion,

the 1 st bus bar has a plate shape in which a plate thickness direction is set in a radial direction of the motor in the axially extending portion.

2. The motor unit according to claim 1,

the axial extension portion has a 1 st end connected to the radial extension portion and a 2 nd end located opposite the 1 st end,

the 1 st bus bar has a circumferential extension extending from a 2 nd end of the axial extension in a circumferential direction of the motor,

the connecting portion is located at the circumferential extension portion.

3. The motor unit according to claim 1 or 2, wherein,

the connecting part is positioned in the inner part of the shell,

the housing is provided with a window portion that opens in a radial direction of the motor and exposes the connection portion.

4. The motor unit according to claim 3,

the shell is provided with an opening hole which enables the inside and the outside of the shell to be communicated,

the 2 nd bus bar protrudes from the inverter case and is inserted into the opening hole.

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

the main body portion has a transmission mechanism which is accommodated in the housing, transmits power of the motor, and outputs the power from an output shaft,

the transmission mechanism includes:

a motor drive shaft extending along a motor axis and rotated by the motor;

a motor drive gear fixed to the motor drive shaft and rotating about the motor axis;

a secondary shaft extending along a secondary axis;

a counter gear fixed to the counter shaft, meshed with the motor drive gear, and rotated about the counter axis;

a drive gear fixed to the counter shaft and rotating about the counter axis;

a ring gear engaged with the drive gear and rotating about an output axis; and

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

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

the motor drive shaft is a hollow shaft that is open on both axial sides of the motor axis,

the output shaft is introduced into the motor drive shaft.

6. The motor unit according to claim 5,

the inverter unit is located directly above the motor,

at least a part of the inverter unit overlaps with a counter gear when viewed from an axial direction of the motor axis.