WO2019059288A1

WO2019059288A1 - In-wheel motor drive device

Info

Publication number: WO2019059288A1
Application number: PCT/JP2018/034852
Authority: WO
Inventors: 真也太向; 四郎田村
Original assignee: Ntn株式会社
Priority date: 2017-09-21
Filing date: 2018-09-20
Publication date: 2019-03-28
Also published as: JP2019055691A; JP6903534B2

Abstract

Provided is an in-wheel motor drive device which is provided with: an electric motor for driving a wheel; a speed reducer which decelerates rotation of the electric motor and outputs the decelerated rotation; a wheel bearing which transmits the output of the speed reducer to the wheel; and a motor housing 55 which houses the electric motor, wherein a terminal box 54 for connecting a plurality of power lines 63 to the electric motor is disposed in the motor housing 55, the terminal box 54 has a plurality of terminal parts 56 for connecting the power lines 63 to lead wires that extend from the electric motor to the motor housing 55, and the terminal parts 56 are arranged in a zigzag form.

Description

In-wheel motor drive

The present invention relates to, for example, an in-wheel motor drive apparatus which inputs rotational driving force of an electric motor to a reduction gear, reduces the number of revolutions, and transmits the reduced speed to a wheel bearing.

As a conventional in-wheel motor drive device, there exists a thing of the structure disclosed by patent document 1, for example.

The in-wheel motor drive device of this patent document 1 includes an electric motor that generates a driving force of the wheel, and a reduction gear that decelerates and outputs the rotation of the electric motor, and rotationally drives the wheel by the rotation output of the electric motor. It is configured to

The in-wheel motor drive device has a structure in which an electric motor and a reduction gear are integrally housed in a casing.

The casing is provided with a terminal box for connecting a power line extending from an external power supply for supplying power to the electric motor.

The terminal box has a structure in which a lead wire extending from an electric motor incorporated in a casing and a power line extending from an external power supply are electrically connected.

JP, 2015-160529, A

By the way, there exist some which equipped the terminal box 154 as shown in FIG. 7, for example in the conventional in-wheel motor drive device. The code | symbol M in a figure shows the internal diameter of a wheel, and the casing 125 is accommodated in the wheel space m.

The terminal box 154 is integrally provided on the outer periphery of the motor housing 155 of the casing 125. The terminal box 154 has three terminal portions 156 to which lead wires (not shown) extending from the electric motor incorporated in the motor housing 155 are connected. Three power lines 153 extending from an external power supply are electrically connected to the terminal portion 156.

The three terminal portions 156 of the terminal box 154 are disposed in a straight line along the longitudinal direction of the vehicle in terms of the commonality of the terminal parts and the workability. Therefore, since it is necessary to secure a creeping distance between the adjacent terminal portions 156, the terminal box 154 becomes large in the vehicle longitudinal direction.

Here, since the damper (not shown) is disposed above the vehicle at the axle center 164, the terminal box 154 can not be enlarged toward the vehicle rear side (close to the axle). As a result, the terminal box 154 has to be enlarged on the front side of the vehicle.

As described above, when the terminal box 154 is enlarged toward the front of the vehicle, the terminal box 154 interferes with the wheel in the vicinity of the terminal box 154. In order to avoid the interference with the wheel, it is necessary to increase the diameter of the wheel.

The increase in diameter of the wheel causes an increase in unsprung weight, which lowers the running stability and the NVH characteristics of the vehicle, leading to a deterioration in ride comfort.

Then, this invention is proposed in view of the above-mentioned subject, and the place made as the purpose is providing the in-wheel motor drive which can attain compactization of a terminal box by simple structure.

The in-wheel motor drive device according to the present invention comprises an electric motor for driving a wheel, a reduction gear for decelerating and outputting the rotation of the electric motor, a wheel bearing for transmitting the output of the reduction gear to a wheel, and an electric motor. And a casing for housing the motor, wherein the casing has a terminal box for connecting a plurality of power lines to the electric motor.

As a technical means for achieving the above-mentioned object, the terminal box of the present invention has a plurality of terminal parts which connect a power wire to a lead wire extended from an electric motor to a casing, and arranges the terminal parts in a zigzag form. It is characterized by having done.

In the present invention, by arranging the plurality of terminal portions in a staggered manner, it is possible to make the terminal box compact while securing the creeping distance between the adjacent terminal portions.

As a result, it is possible to avoid an increase in the diameter of the wheel, and by suppressing an increase in the unsprung weight, it is possible to prevent the traveling stability of the vehicle and the deterioration of the NVH characteristics and the deterioration of the riding comfort.

The terminal portion in the present invention preferably has a structure in which an insulating terminal block is attached to the casing, and the connection end portion of the power line is screwed to the connection end portion of the lead wire drawn from the terminal block.

By adopting such a structure, it becomes easy to secure a creeping distance between adjacent terminal portions in a plurality of terminal portions constituted by both connecting ends of the lead wire and the power line.

The terminal box in the present invention preferably has a structure in which a part of the outer peripheral portion of the casing integrally protrudes radially outward, and a structure in which a terminal portion is provided on an axial end surface of the terminal box.

If such a structure is adopted, it becomes easy to avoid an increase in diameter of the wheel due to the compactness of the terminal box.

According to the present invention, the terminal box can be made compact while securing the creeping distance between the adjacent terminal portions. As a result, it is possible to avoid an increase in the diameter of the wheel, and by suppressing an increase in the unsprung weight, it is possible to prevent the traveling stability of the vehicle and the deterioration of the NVH characteristics and the deterioration of the riding comfort. As a result, a high-performance in-wheel motor drive can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the whole structure of an in-wheel motor drive device by embodiment of this invention. It is the front view which looked at the in-wheel motor drive device of FIG. 1 from the vehicle (in board) side. It is an enlarged front view which shows the terminal box of FIG. FIG. 10 is an enlarged front view showing a terminal box according to another embodiment of the present invention. It is a top view which shows schematic structure of the electric vehicle carrying an in-wheel motor drive device. FIG. 6 is a rear sectional view showing the electric vehicle of FIG. 5; It is the front view which looked at the conventional in-wheel motor drive from the vehicle (in board) side.

An embodiment of an in-wheel motor drive device according to the present invention will be described in detail based on the drawings. FIG. 5 is a schematic plan view of the electric vehicle 11 equipped with the in-wheel motor drive device 21. FIG. 6 is a schematic cross-sectional view of the electric vehicle 11 as viewed from the rear.

As shown in FIG. 5, the electric vehicle 11 includes a chassis 12, a front wheel 13 as a steered wheel, a rear wheel 14 as a drive wheel, and an in-wheel motor drive device 21 for transmitting a driving force to the rear wheel 14. Equip. As shown in FIG. 6, the rear wheel 14 is housed inside the wheel housing 15 of the chassis 12 and is fixed to the lower part of the chassis 12 via an independent suspension type suspension system (suspension) 16.

The electric vehicle 11 eliminates the need to provide a motor, a drive shaft, a differential gear mechanism, etc. on the chassis 12 by providing in-wheel motor drive devices 21 for driving the left and right rear wheels 14 inside the wheel housing 15 . As a result, it is possible to secure a large cabin space and to control the rotation of the left and right rear wheels 14 respectively.

In order to improve the running stability and the NVH characteristics of the electric vehicle 11, it is necessary to suppress the unsprung weight, and in addition, the in-wheel motor drive device 21 is required to be downsized in order to secure a large cabin space.

Therefore, the in-wheel motor drive device 21 of the embodiment shown in FIG. 1 has the following structure. As a result, a compact in-wheel motor drive device 21 is realized, and the unsprung weight is suppressed to obtain the electric vehicle 11 excellent in traveling stability and the NVH characteristics.

Before describing the characteristic configuration of this embodiment, the overall configuration of the in-wheel motor drive device 21 will be described. In the following description, in the state where the in-wheel motor drive device 21 is mounted on the vehicle body, the side closer to the outer side of the vehicle is referred to as the outboard side (left side in the drawing) and the side closer to the center is the inboard side (right side in the drawing) It is called.

As shown in FIG. 1, the in-wheel motor drive device 21 has an electric motor 22 for driving the wheels, a parallel shaft gear reducer 23 for decelerating and outputting the rotation of the electric motor 22, and a parallel shaft gear reducer A wheel bearing 24 is provided for transmitting the twenty-three output to the rear wheel 14 (see FIGS. 5 and 6) which is a driving wheel.

In this embodiment, although the radial gap type electric motor 22 is illustrated, another electric motor such as an axial gap type may be used. Further, although the parallel shaft gear reducer 23 is illustrated, it may be another reducer such as a planetary gear reducer or a cycloid reducer.

The electric motor 22 and the parallel shaft gear reducer 23 are accommodated in a casing 25. A casing 25 in which the electric motor 22 and the parallel shaft gear reducer 23 are housed is mounted in a wheel housing 15 (see FIG. 6) of the electric vehicle 11.

The electric motor 22 is disposed integrally with the rotor 27. The stator 26 is fixed to the casing 25. The rotor 27 is disposed so as to face the radial inner side of the stator 26 with a gap. And a motor rotation shaft 28.

The motor rotation shaft 28 can rotate at a high speed of about ten thousand and several thousand revolutions per minute. The stator 26 is configured by winding a coil around the outer periphery of the magnetic core. The rotor 27 has a permanent magnet or a magnetic body disposed therein.

The motor rotation shaft 28 holds the rotor 27 by means of a holder portion 29 integrally extending outward in the radial direction. The holder portion 29 has a configuration in which a recessed groove in which the rotor 27 is fitted and fixed is formed in an annular shape. The motor rotation shaft 28 is rotatably supported by the rolling bearings 30 and 31 with respect to the casing 25.

The parallel shaft gear reducer 23 is configured of an input gear 32, an intermediate gear 33, and an output gear 34. The intermediate gear 33 coaxially has a large diameter tooth portion 35 on the inboard side and a small diameter tooth portion 36 on the outboard side.

In the parallel shaft gear reducer 23, the teeth 37 of the input gear 32 mesh with the large diameter teeth 35 of the intermediate gear 33, and the small diameter teeth 36 of the intermediate gear 33 mesh with the teeth 38 of the output gear 34. Thus, the rotation of the electric motor 22 is decelerated at a predetermined reduction ratio.

The in-wheel motor drive device 21 is housed inside the wheel housing 15 (see FIG. 6) and has an unsprung weight, so reduction in size and weight is essential. Therefore, by using the parallel shaft gear reducer 23 having a large reduction ratio, the electric motor 22 can be miniaturized by combining with the electric motor 22 rotating at high speed, and the in-wheel motor drive 21 having a compact and high reduction ratio is realized. To realize.

The input gear 32 is coaxially attached to the motor rotation shaft 28 by spline fitting. The input gear 32, the intermediate gear 33 and the output gear 34 are rotatably supported on the casing 25 by rolling bearings 39-44. The output gear 34 is coaxially attached to the hub wheel 46 of the wheel bearing 24 by spline fitting.

Here, helical gears are used for the input gear 32, the intermediate gear 33 and the output gear 34. The helical gear is effective in that the noise is quiet and the torque fluctuation is small because the number of meshing teeth simultaneously increases and the tooth contact is dispersed.

As described above, by using a helical gear for the parallel shaft gear reducer 23, it is possible to realize the in-wheel motor drive device 21 which is easy to manufacture and can reduce the cost and which has a quiet and efficient performance. it can.

The wheel bearing 24 includes an outer ring 45 fixed to the casing 25, an inner ring 47 press-fit to the hub wheel 46 and the hub ring 46 disposed inside the outer ring 45, and the hub ring 46 and the inner ring 47 and the outer ring 45 A main part is constituted by a plurality of rolling elements 48 disposed between the two.

Precompression is applied to the wheel bearing 24 by caulking the inboard end of the hub wheel 46. By applying this preload, the wheel bearing 24 has a double-row angular contact ball bearing structure.

A shaft portion 50 integrally extending from the output gear 34 of the parallel shaft gear reducer 23 to the outboard side is coupled to an axial hole 49 of the hub wheel 46 of the wheel bearing 24 so as to be capable of transmitting torque by spline fitting. .

Seal members 51 are provided at both axial end portions of the wheel bearing 24 for the purpose of preventing the entry of mud water and the like and the leakage of grease.

A flange 52 is integrally formed on the outboard side of the hub wheel 46, and the rear wheel 15 (see FIGS. 5 and 6) is connected to the flange 52 by the hub bolt 53.

In the in-wheel motor drive device 21 configured as described above, the rotation of the electric motor 22 is decelerated by the input gear 32, the intermediate gear 33 and the output gear 34 of the parallel shaft gear reducer 23, and transmitted to the wheel bearing 24.

As described above, since the rotation of the electric motor 22 is reduced by the parallel shaft gear reducer 23 and transmitted to the wheel bearing 24, the rear wheel 14 (the low torque, high speed rotation type electric motor 22) is employed. It is possible to transmit the required torque in FIGS. 5 and 6).

In the in-wheel motor drive device 21, a lubricating oil for cooling the electric motor 22 and cooling and lubricating the parallel-shaft gear reducer 23 is enclosed in the casing 25.

The lubricating oil cools the electric motor 22 by the rotation of the rotor 27 and cools and lubricates the parallel shaft gear reducer 23 by splashing by the rotation of the input gear 32, the intermediate gear 33 and the output gear 34.

Although the whole structure of the in-wheel motor drive device 21 in this embodiment is as above-mentioned, the characteristic structure is explained in full detail below.

As shown in FIG. 2, a power line extending from an external power supply (not shown) for supplying power to electric motor 22 to casing 25 accommodating electric motor 22 and parallel shaft gear reduction gear 23 (see FIG. 1). A terminal box 54 for connecting 63 is provided. The code | symbol M in a figure shows the internal diameter of a wheel, and the casing 25 is accommodated in the wheel space m.

The in-wheel motor drive device 21 includes a parallel-shaft gear reducer 23 in which an axle center 64 and a motor axis center 62 are offset in the longitudinal direction of the vehicle. The code | symbol 65 in a figure is a reduction gear housing which accommodates parallel axis gear reduction gear 23. FIG.

The terminal box 54 is integrally provided on the outer peripheral upper portion of the motor housing 55 of the casing 25 so as to protrude radially outward. At the axial direction end face of the terminal box 54, three terminal portions 56 are provided in which lead wires extending from the electric motor 22 (see FIG. 1) incorporated in the motor housing 55 are derived. Three power lines 63 extending from an external power supply (not shown) are electrically connected to the terminal portion 56.

In this embodiment, as shown in FIG. 2, the terminal portion 56 of the terminal box 54 is disposed on the inboard side of the motor housing 55, but is disposed on the outboard side of the motor housing 55. It is also possible to set up.

The three terminal portions 56 of the terminal box 54 are provided with insulating terminal blocks 57 in the form of teardrops. The small diameter portion 58 of the terminal block 57 is fixed to the casing 25 by screwing or the like. The large diameter portion 59 of the terminal block 57 is formed with a small hole through which the connection end portion 60 of the lead wire extending from the electric motor 22 is inserted. The connection end portion 60 of the lead wire inserted into the small hole is led out to the outside.

On the other hand, a crimp terminal is attached by caulking to the connection end 61 of the power line 63 extending from the external power supply. A small hole through which the connection end portion 60 of the lead wire is inserted is formed at the tip of the crimp terminal. A screw is engraved at the connection end 60 of the lead wire.

In the terminal portion 56 configured as described above, the crimp terminal of the connection end portion 61 of the power wire 63 is inserted through the connection end portion 60 of the lead wire led out from the small hole of the terminal block 57 attached to the casing 25; A nut member (not shown) is screwed on and fixed to the connection end 60 of the lead wire.

Thus, the connection end 60 of the lead wire and the connection end 61 of the power line 63 are electrically connected. Thus, the terminal portion 56 is constituted by both the connecting

end portions

60 and 61 of the lead wire and the power line 63. Hereinafter, both

connection end portions

60 and 61 of the lead wire and the power line 63 will be referred to as a terminal portion 56.

The terminal box 54 of this embodiment has a structure in which three terminal portions 56 are arranged in a staggered manner. That is, as shown in the enlarged view of FIG. 3, the terminal block 57 of the terminal 56 located at the center is disposed with its small diameter portion 58 down and its large diameter portion 59 up. On the other hand, the terminal blocks 57 of the terminal portions 56 located on the left and right sides are arranged with the small diameter portion 58 up and the large diameter portion 59 down.

With such an arrangement, the terminal portions 56 which are both

connection end portions

60 and 61 of the lead wire and the power line 63 are arranged in a zigzag (triangular shape). As described above, by arranging the three terminal portions 56 in a staggered manner by shifting the three terminal portions 56 in the vertical direction of the vehicle, it is possible to make the terminal box 54 compact while securing the creeping distance between the adjacent terminal portions 56.

That is, the creeping distance between the adjacent terminal portions 56 is secured by arranging the terminal portion 56 located at the center on the vehicle upper side and arranging the terminal portions 56 located on the left and right on the vehicle lower side to form a zigzag. can do.

In particular, the terminal portion 56 located on the left side can be largely shifted to the vehicle lower side than the terminal portion 56 located on the right side. This is because the terminal portion 56 located on the left side is more distant from the motor shaft center 62 in the vehicle longitudinal direction than the terminal portion 56 located on the right side on the outer periphery of the motor housing 55.

Therefore, the creeping distance between the terminal portion 56 located at the center and the terminal portion 56 located on the left side is larger than the creeping distance between the terminal portion 56 located at the center and the terminal portion 56 located on the right. This makes it easy to secure the creeping distance between the terminal portions 56.

As described above, after securing the creeping distance between the adjacent terminal portions 56, the terminal box 54 can be reduced in the longitudinal direction of the vehicle. That is, the terminal box 54 (see FIG. 2) can be made smaller on the front side of the vehicle than the conventional terminal box 154 (see FIG. 7) (L1 <L2).

By thus reducing the size of the terminal box 54 on the front side of the vehicle, interference between the terminal box 54 and the wheel can be avoided. As a result, it is possible to avoid an increase in the diameter of the wheel, and by suppressing an increase in the unsprung weight, it is possible to prevent the traveling stability of the vehicle and the deterioration of the NVH characteristics and the deterioration of the riding comfort.

Although the above embodiment exemplifies a structure in which the three terminal portions 56 are arranged in a triangular shape, the present invention is not limited to this, and as shown in FIG. It may be arranged in a triangular shape.

That is, in the terminal box 54 of the embodiment shown in FIG. 4, the terminal block 57 of the terminal portion 56 located at the center is disposed with its small diameter portion 58 up and its large diameter portion 59 down. There is. On the other hand, the terminal blocks 57 of the terminal portions 56 located on the left and right sides are disposed with the small diameter portion 58 down and the large diameter portion 58 upward.

With such an arrangement, the terminal portions 56 which are both

connection end portions

60 and 61 of the lead wire and the power line 63 are arranged in a zigzag shape (inverted triangle shape). As described above, by arranging the three terminal portions 56 in a staggered manner by shifting the three terminal portions 56 in the vertical direction of the vehicle, it is possible to make the terminal box 54 compact while securing the creeping distance between the adjacent terminal portions 56.

That is, the creeping distance between adjacent terminal parts 56 is secured by arranging the terminal parts 56 located in the center on the vehicle lower side and arranging the terminal parts 56 located on the left and right on the vehicle upper side to make them staggered. can do.

As described above, after securing the creeping distance between the adjacent terminal portions 56, the terminal box 54 can be reduced in the longitudinal direction of the vehicle. That is, by making the terminal box 54 smaller on the vehicle front side, interference between the terminal box 54 and the wheel can be avoided.

In the above embodiment, as shown in FIG. 5 and FIG. 6, the electric vehicle 11 in which the rear wheel 14 is a drive wheel is illustrated, but the front wheel 13 may be a drive wheel or a four-wheel drive vehicle . In the present specification, the term "electric car" is a concept including all cars obtaining driving power from electric power, and also includes, for example, a hybrid car and the like.

The present invention is not limited to the embodiment described above, and it goes without saying that the present invention can be practiced in various forms without departing from the scope of the present invention, and the scope of the present invention is defined by And the meaning of equivalents described in the claims, and all changes within the range.

Claims

A plurality of electric motors for driving the wheels, a reduction gear for decelerating and outputting the rotation of the electric motor, a wheel bearing for transmitting the output of the reduction gear to the wheels, and a casing for accommodating the electric motor An in-wheel motor drive device in which a terminal box for connecting a power line of the motor to the electric motor is disposed in the casing,
The in-wheel motor drive according to claim 1, wherein the terminal box includes a plurality of terminal portions for connecting the power line to a lead wire extending from the electric motor to the casing, and the terminal portions are arranged in a zigzag manner.
The in-wheel according to claim 1, wherein the terminal portion has a structure in which an insulating terminal block is attached to a casing, and a connection end portion of a power line is screwed to a connection end portion of a lead wire drawn from the terminal block. Motor drive.
The terminal box according to claim 1 or 2, wherein the terminal box has a structure in which a part of the outer peripheral portion of the casing integrally protrudes outward in the radial direction, and the terminal portion is provided on an axial end surface of the terminal box. Wheel motor drive.