WO2023145468A1

WO2023145468A1 - Wheel unit, in-wheel motor

Info

Publication number: WO2023145468A1
Application number: PCT/JP2023/000634
Authority: WO
Inventors: 和也榎園; 晴美堀畑; 貞洋赤間; 恵介河合
Original assignee: 株式会社デンソー
Priority date: 2022-01-31
Filing date: 2023-01-12
Publication date: 2023-08-03
Also published as: JP2023111214A

Abstract

A wheel unit comprises a wheel (30) having a rim section (31) to which a tire (33) can be attached and a disk section (32) provided to the vehicle-widthwise outer side of the rim section, and an in-wheel motor (40) that is at least partially accommodated in a space inside the wheel surrounded by the disk section and the rim section and that causes the wheel to rotate. The wheel is steerably attached to the body of a vehicle via a suspension device (10). The wheel unit also comprises a knuckle (11) provided on the vehicle-widthwise inner side of the wheel, and a lower ball joint (16) through which a kingpin axis passes. A lower arm connecting part (11b) is provided at the lower end of the knuckle. A lower ball joint rotatably connects the lower arm connecting part and the vehicle-widthwise outside end of a lower arm (12) constituting the suspension device. The lower ball joint is located in the space inside the wheel.

Description

Wheel unit, in-wheel motor

Cross-reference to related applications

This application is based on Japanese Application No. 2022-012958 filed on January 31, 2022, and the contents thereof are incorporated herein.

The present disclosure relates to a wheel unit and an in-wheel motor that constitutes the wheel unit.

Conventionally, a wheel unit is known that includes a wheel and an in-wheel motor that rotates the wheel, as described in Patent Document 1, for example. The wheel has a rim portion to which a tire can be attached, and a disk portion provided on the outer side in the vehicle width direction of the rim portion. At least a portion of the in-wheel motor is housed in a space inside the wheel surrounded by the disk portion and the rim portion.

Japanese Patent No. 6095267

If you try to increase the power performance such as the torque and output of the in-wheel motor, the size of the in-wheel motor will increase, and the ratio of the in-wheel motor to the space inside the wheel will increase. In this case, the knuckles involved in steering the wheel may have to be arranged outside the wheel. In this case, the kingpin axis, which is the central axis of steering, is separated inward in the vehicle width direction with respect to the ground contact center of the tire with respect to the ground when the vehicle is viewed from the front or rear. As a result, the kingpin offset, which is the distance between the tire contact center and the intersection of the kingpin axis and the ground, increases. In this case, there is a concern that the steering performance of the vehicle will deteriorate, such as the steering stability of the vehicle will deteriorate.

A main object of the present disclosure is to provide a wheel unit that can improve the steering performance of a vehicle, and an in-wheel motor that constitutes the wheel unit.

A first disclosure is a wheel having a rim portion to which a tire can be attached, and a disc portion provided on the outer side in the vehicle width direction of the rim portion;
an in-wheel motor that is at least partially accommodated in a wheel inner space surrounded by the disk portion and the rim portion and that rotates the wheel;
In a wheel unit in which the wheel is steerably attached to the vehicle body via a suspension device,
a knuckle provided inside the wheel in the vehicle width direction;
A lower ball joint through which the kingpin axis passes,
with
A lower arm connecting portion is provided at the lower end of the knuckle,
the lower ball joint rotatably connects a vehicle width direction outer end portion of a lower arm constituting the suspension device and the lower arm connecting portion;
The lower ball joint is arranged in the wheel inner space.

In the first disclosure, a lower ball joint that constitutes a steering portion is arranged in the wheel inner space. Therefore, the connecting portion between the lower arm connecting portion of the knuckle and the lower arm can be arranged further outside in the vehicle width direction. As a result, the kingpin offset can be reduced. Therefore, according to the first disclosure, it is possible to improve the steering performance of the vehicle while effectively utilizing the space inside the wheel as the arrangement space for the connecting portion between the lower arm connecting portion of the knuckle and the lower arm.

A second disclosure is a wheel having a rim portion to which a tire can be attached, and a disk portion provided on the outer side in the vehicle width direction of the rim portion,
a knuckle provided inside the wheel in the vehicle width direction;
a suspension device that attaches the wheel to a vehicle body so as to be steerable;
A vehicle comprising: a lower ball joint that rotatably connects a vehicle width direction outer end portion of a lower arm that constitutes the suspension device and a lower arm connecting portion that is provided at a lower end portion of the knuckle, and through which a kingpin axis passes; applied to
In the in-wheel motor that rotates the wheel,
The in-wheel motor is an outer rotor type motor including a rotor and a stator arranged radially inside the rotor,
The rotor is
a cylindrical magnet holding portion housed in a wheel inner space surrounded by the disk portion and the rim portion;
a magnet unit provided on the inner peripheral surface of the magnet holding portion and forming a plurality of magnetic poles with alternating polarities in the circumferential direction;
a shaft extending in the vehicle width direction;
a connecting portion provided at the outer end in the vehicle width direction of the magnet holding portion and housed in the wheel inner space for connecting the magnet holding portion and the shaft;
The stator has a cylindrical stator winding arranged at a position facing the magnet unit in the radial direction of the stator,
A hollow portion that is recessed outward in the vehicle width direction is formed in a portion of the stator that faces the lower ball joint and the lower arm connecting portion in the vehicle width direction, and is the inner portion of the stator in the vehicle width direction.
The cavity is formed between the stator winding and the shaft in the wheel inner space,
The lower ball joint is arranged in the cavity.

In the second disclosure, the lower ball joint is arranged in the cavity of the motor in the wheel inner space. Therefore, the connecting portion between the lower arm connecting portion of the knuckle and the lower arm can be arranged further outside in the vehicle width direction. As a result, the kingpin offset can be reduced. Therefore, according to the second disclosure, there is provided a motor capable of enhancing the steering performance of a vehicle while effectively using the hollow portion in the inner space of the wheel as the arrangement space for the connecting portion between the lower arm connecting portion of the knuckle and the lower arm. can.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a perspective view showing a front wheel, a suspension device, a brake device, etc. according to the first embodiment, FIG. 2 is a cross-sectional view of the front wheel and suspension device; FIG. 3 is a perspective view showing the configuration of the knuckle and its surroundings; FIG. 4 is a perspective view showing the configuration of the knuckle and its surroundings with the brake disc and the like removed; FIG. 5 is a diagram of the in-wheel motor viewed from the inside in the vehicle width direction, FIG. 6 is an enlarged perspective view showing the vicinity of the guide portion of the knuckle, FIG. 7 is a diagram showing the electrical connection of the stator windings, the inverter and the storage battery; FIG. 8 is a cross-sectional view of the front wheel and suspension device according to the second embodiment, FIG. 9 is a cross-sectional view of a front wheel and suspension device according to another embodiment.

<First embodiment>
A first embodiment embodying a wheel unit according to the present disclosure will be described below with reference to the drawings. The wheel unit includes a wheel to which a tire is attached and a motor (in-wheel motor) housed in the inner space of the wheel. In this embodiment, a vehicle including two front wheels and two rear wheels will be described as an example of a vehicle including wheel units. Each front wheel is a drive wheel equipped with an in-wheel motor and a steerable steering wheel. In addition, each rear wheel may be a driving wheel provided with an in-wheel motor, or may be a driven wheel not provided with an in-wheel motor. The front wheel will be described below as an example with reference to FIGS. 1 to 6. FIG.

In addition to the wheels 30 and the in-wheel motors 40, the vehicle includes a suspension device 10 that mitigates shock and vibration received by the front wheels from the ground (road surface), a steering device that steers the front wheels, and a braking force that is applied to the front wheels. Equipped with a braking device.

The wheel 30 includes a cylindrical rim portion 31 and a disc-like disk portion 32 provided at the outer end of the rim portion 31 in the vehicle width direction. A tire 33 is attached to the outer circumference of the wheel 30 . A front wheel is configured by the wheel 30 and the tire 33 .

The front wheels are attached to the vehicle body via a suspension device 10. The suspension system 10 of the present embodiment is an independent suspension system, more specifically, a wishbone suspension system. Specifically, the suspension device 10 includes a knuckle 11 , a lower arm 12 and an upper arm 13 extending in the vehicle width direction, a shock absorber 14 extending in the vertical direction, and a spring 15 .

Attached to the knuckle 11 are a tie rod 21 that constitutes a steering device, a brake caliper 92 that constitutes a braking device, a hub bearing 70 that rotatably supports the shaft 41 of the in-wheel motor 40, and the like. The knuckle 11 includes a plate-shaped base portion 11a extending in the vertical direction, a lower arm connecting portion 11b extending outward in the vehicle width direction from the vehicle length direction central portion of the lower end portion of the base portion 11a, and a vehicle portion of the upper end portion of the base portion 11a. An upper arm connecting portion 11c extending inward in the vehicle width direction from the central portion in the longitudinal direction is provided. The knuckle 11 also includes a rod connecting portion 11d provided at a portion of the lower end portion of the base portion 11a adjacent to the lower arm connecting portion 11b in the vehicle length direction. In this embodiment, the base portion 11a, the lower arm connecting portion 11b, the upper arm connecting portion 11c, and the rod connecting portion 11d are integrally formed.

A through hole 11e is formed in the central portion of the base portion 11a. A shaft 41 of the in-wheel motor 40 is inserted through the through hole 11e.

The lower arm 12 includes an arm base portion 12a to which the shock absorber 14 is rotatably attached, a pair of lower mounting portions 12b extending inwardly in the vehicle width direction from the arm base portion 12a, and a pair of lower mounting portions 12b extending inwardly in the vehicle width direction from the arm base portion 12a. and a lower connecting portion 12d extending outward in the vehicle width direction from the end of the inclined arm portion 12c. A lower connecting portion 12d, which is the outer end portion of the lower arm 12 in the vehicle width direction, is connected to the lower arm connecting portion 11b constituting the knuckle 11 via a lower ball joint 16. As shown in FIG. Specifically, the lower ball joint 16 includes a ball stud fixed to the lower arm connecting portion 11b, a socket attached to the lower connecting portion 12d and holding the ball portion of the ball stud, and a sliding portion of the ball stud and the socket. Equipped with a dust boot. As a result, the lower arm 12 is rotatable with respect to the lower arm connecting portion 11b.

The upper arm 13 includes an upper connecting portion 13a and a pair of upper mounting portions 13b extending inward in the vehicle width direction from the upper connecting portion 13a. An upper connecting portion 13 a , which is an outer end portion of the upper arm 13 in the vehicle width direction, is connected via an upper ball joint 17 to the upper arm connecting portion 11 c that constitutes the knuckle 11 . Specifically, the upper ball joint 17 includes a ball stud fixed to the upper arm connecting portion 11c, a socket attached to the upper connecting portion 13a and holding the ball portion of the ball stud, and a sliding portion of the ball stud and the socket. It is equipped with a covering dust boot. Thereby, the upper arm 13 is rotatable with respect to the upper arm connecting portion 11c.

A lower ball joint 16 (specifically, for example, a ball portion of a ball stud that constitutes the lower ball joint 16) and an upper ball joint 17 (specifically, for example, a ball portion of a ball stud that constitutes the upper ball joint 17). The axis passing through is the kingpin axis LKG, which is the central axis of the steering shaft of the front wheels. The kingpin axis LKG is inclined inward in the vehicle width direction with respect to the contact center axis Ltc of the tire 33 with respect to the ground. In this embodiment, the intersection of the kingpin axis LKG and the ground intersects the contact surface of the tire 33 . This improves the steering stability of the vehicle.

The angle between the kingpin axis LKG and the axis extending in the vertical direction is the kingpin angle θ. A kingpin offset Lofs is the distance between the contact center axis Ltc of the tire 33 with respect to the ground and the intersection of the kingpin axis LKG and the ground when the vehicle is viewed from the front or rear. In the example shown in FIG. 2, the kingpin offset Lofs is approximately zero.

The distance in the vehicle width direction between the base portion 11a that constitutes the knuckle 11 and the kingpin axis LKG becomes smaller as the shaft 41 approaches the ground. That is, the closer the lower arm connecting portion 11b is to the shaft 41 with respect to the ground, the smaller the length of the lower arm connecting portion 11b in the vehicle width direction. In view of this point, the lower arm connecting portion 11b is arranged closer to the shaft 41 than the central position from the central axis of the shaft 41 to the contact surface of the tire 33 in the vertical direction. As a result, the longitudinal dimension of the lower arm connecting portion 11b constituting the knuckle 11 in the vehicle width direction and the vertical dimension of the base portion 11a can be reduced. As a result, the size of the knuckle 11 can be reduced, the material used for manufacturing the knuckle 11 can be reduced, and the weight of the knuckle 11 can be reduced.

The shock absorber 14 is arranged inside the wheel 30 in the vehicle width direction. A lower end portion of the shock absorber 14 is attached to an arm base portion 12 a that constitutes the lower arm 12 , and an upper end portion of the shock absorber 14 is attached to the vehicle body above the wheel 30 . The shock absorber 14 is arranged between the pair of upper mounting portions 13b.

The shock absorber 14 has a built-in damper and can extend and contract in the vertical direction. A spring 15 is arranged radially outside the shock absorber 14 . The shock absorber 14 is provided with a spring stopper 14a at its upper end and a spring seat 14b at its intermediate portion. A spring 15 is sandwiched and held by the spring stopper 14a and the spring seat 14b. A bolt 14c for attaching the upper end of the shock absorber 14 to the vehicle body is provided above the spring stopper 14a. A nut is screwed onto the bolt 14c while the bolt 14c is inserted through a hole provided in the vehicle body. Thereby, the upper end portion of the shock absorber 14 is attached to the vehicle body.

A stabilizer 20 is attached to the arm base portion 12a that constitutes the lower arm 12 to suppress the inclination of the vehicle body when the vehicle turns.

A tie rod 21 is rotatably connected to the rod connecting portion 11d that constitutes the knuckle 11 via a ball joint (not shown). The tie rod 21 is arranged above the lower arm 12 . When the steering wheel of the vehicle is operated by the driver, the tie rod 21 moves in the vehicle width direction to steer the front wheel attached to the knuckle 11 around the kingpin axis LKG.

The in-wheel motor 40 is housed in the inner space of the wheel 30 and imparts rotational power to the wheel 30 . The in-wheel motor 40 is an outer rotor type motor including a shaft 41 extending in the vehicle width direction, a rotor 50 , and a stator 60 arranged radially inside the rotor 50 .

The rotor 50 includes a cylindrical magnet holding portion 51 and a magnet unit 52 provided on the inner peripheral surface of the magnet holding portion 51 . The magnet holding portion 51 faces the inner peripheral surface of the rim portion 31 from the outer end to the inner end in the vehicle width direction. The magnet unit 52 has a cylindrical shape concentric with the rotation center axis of the rotor 50 and has a plurality of magnets fixed to the inner peripheral surface of the magnet holder 51 . That is, the in-wheel motor 40 of this embodiment is a surface magnet type synchronous machine (SPMSM). In the magnet unit 52 , the magnets are arranged so that their polarities alternate along the circumferential direction of the rotor 50 . Thereby, a plurality of magnetic poles are formed in the magnet unit 52 in the circumferential direction. The magnet is, for example, a polar anisotropic permanent magnet, a sintered neodymium magnet having an intrinsic coercive force of 400 [kA/m] or more and a residual magnetic flux density Br of 1.0 [T] or more. . Incidentally, the in-wheel motor 40 may be an embedded magnet type synchronous machine (IPMSM).

The inner end in the vehicle width direction of the magnet holding portion 51 is a bent portion bent radially inward of the rotor 50 . The rotor 50 includes a disk-shaped flat plate portion 53 (corresponding to a “connecting portion”) that is provided at the outer end portion in the vehicle width direction of the magnet holding portion 51 and connects the magnet holding portion 51 and the shaft 41 . . The disk portion 32 is fixed to the flat plate portion 53 with bolts and nuts. As a result, the rotor 50 and the wheel 30 rotate together.

The stator 60 includes a cylindrical stator winding 61 arranged at a position facing the magnet unit 52 in the radial direction, and a stator base portion 62 provided radially inside the stator winding 61 . ing. A radially outer portion of the stator base portion 62 is a magnetic stator core.

The stator winding 61 has a plurality of phase windings, and is formed in a cylindrical shape by arranging the phase windings of each phase in a predetermined order in the circumferential direction. In this embodiment, the stator winding 61 is composed of U-, V-, and W-phase windings. Each phase winding is composed of multiple windings of a conducting wire, and includes a pair of intermediate conducting wire portions that are parallel to each other and extend in the axial direction (vehicle width direction) of the shaft 41, and a pair of intermediate conducting wire portions that are arranged at both ends in the axial direction. and a pair of transition portions connected to each other by the pair of intermediate conductor portions and the pair of transition portions.

In this embodiment, the stator 60 has a slotless structure without teeth for forming slots. This structure may be a structure using any one of the following (A) to (C).
(A) In the stator 60, an inter-conductor member is provided between each intermediate conductor portion in the circumferential direction, and as the inter-conductor member, the width dimension of the inter-conductor member in one magnetic pole in the circumferential direction is Wt, and the width of the inter-conductor member is A magnetic material that satisfies the relationship Wt×Bs≦Wm×Br, where Bs is the saturation magnetic flux density, Wm is the width dimension of the magnet in the circumferential direction of one magnetic pole, and Br is the residual magnetic flux density of the magnet that constitutes the magnet unit 52. The structure in which is used.
(B) In the stator 60, a structure in which an inter-conductor wire member is provided between each intermediate wire portion in the circumferential direction, and a non-magnetic material is used as the inter-conductor wire member.
(C) In the stator 60, a structure in which inter-conductor members are not provided between intermediate conductor portions in the circumferential direction.

A hollow portion 63 recessed outward in the vehicle width direction is formed at the inner end portion of the stator base portion 62 in the vehicle width direction. In this embodiment, the cavity 63 is annularly provided between the stator winding 61 and the shaft 41 . Due to the slotless structure having no teeth, the radial inner space can be increased with respect to the stator windings 61, and the cavity 63 can be increased.

A shaft insertion hole 65 through which the shaft 41 is inserted is formed in the radial center portion of the stator base portion 62 . A bearing 64 is provided at the central portion of the outer end portion of the stator base portion 62 in the vehicle width direction. The bearing 64 is, for example, a radial ball bearing, and has an outer ring, an inner ring, and a plurality of rolling elements (balls) arranged between the outer ring and the inner ring. The inner ring is fixed to the shaft 41 and the outer ring is fixed to the stator base portion 62 . Thereby, the shaft 41 is rotatably supported with respect to the stator base portion 62 .

The inner space of the wheel 30 surrounded by the rim portion 31 and the disk portion 32 accommodates the lower ball joint 16 that constitutes the steering portion. At least part of the lower ball joint 16 is housed in the hollow portion 63 , and the entire lower ball joint 16 is housed in the hollow portion 63 in this embodiment. Even when the steering angle of the front wheels to the left and right reaches the maximum angle due to the operation of the steering wheel, the connecting portion between the lower arm connecting portion 11b and the lower arm 12 does not interfere with the stator base portion 62. - 特許庁

A portion of the hollow portion 63 above the shaft 41 faces the base portion 11a forming the knuckle 11 . A connector portion 66 is provided on the upper portion thereof, as shown in FIG. Each phase winding constituting the stator winding 61 is electrically connected to the connector portion 66 . The connector portion 66 is electrically connected to each phase winding to the inverter 80, and is electrically connected to a first end of a power line 81 (corresponding to "wiring") through which a three-phase alternating current flows. The inverter 80 is electrically connected to the second end of the power line 81 . As shown in FIG. 7 , a power storage unit 82 is electrically connected to the inverter 80 . The power storage unit 82 is, for example, a storage battery such as a lithium ion storage battery. Switching control of the upper and lower arm switches that constitute inverter 80 is performed by control device 83 . This causes the rotor 50 to rotate and the front wheels to rotate. In this embodiment, the inverter 80, the power storage unit 82, and the control device are provided in the vehicle body.

A base portion 11a that constitutes the knuckle 11 is fixed to the central portion of the inner end portion of the stator base portion 62 in the vehicle width direction. A concave portion 11f that is recessed inward in the vehicle width direction is formed from a portion of the base portion 11a facing the connector portion 66 in the vehicle width direction to the upper end of the base portion 11a.

The power line 81 is laid from the connector portion 66 to the upper arm 13 side via the recess 11f and the upper arm connecting portion 11c. As a result, twisting of the power line 81 due to steering of the front wheels can be suppressed.

A guide portion 11g is provided on the knuckle 11 so as to cover the concave portion 11f from the outside in the vehicle width direction. This can prevent the power line 81 from protruding from the recess 11f toward the wheel 30 and prevent the power line 81 from interfering with rotating members such as the wheel 30 and the rotor 50 . The guide portion 11g is cantilevered and fixed to the base portion 11a. This facilitates the wiring work of passing the power line 81 through the recess 11f.

A hub bearing 70 that rotatably supports the shaft 41 is fixed to the base portion 11a that constitutes the knuckle 11 on the side opposite to the wheel. In this embodiment, the stator base portion 62 and the hub bearing 70 are fixed to the knuckle 11 using a rod-shaped protrusion 67 extending inward in the vehicle width direction from the stator base portion 62 and a nut 68 . Specifically, the stator base portion 62 is provided with a plurality of (four) projecting portions 67 . A through hole 11h through which the protrusion 67 is inserted is formed in a portion of the base portion 11a that faces the protrusion 67. As shown in FIG.

The hub bearing 70 includes a cylindrical outer ring 71 , an inner ring 72 , and a plurality of rolling elements 73 (balls, for example) arranged between the outer ring 71 and the inner ring 72 . The inner ring 72 has a cylindrical portion 72a having a smaller diameter than the outer ring 71 and a flange portion 72b extending from one axial end of the cylindrical portion 72a in a direction intersecting (perpendicular to) the axial direction. A radially extending mounting portion 71 a is provided at one axial end portion of the outer ring 71 . A through hole is formed at a position of the mounting portion 71 a facing the through hole 11 h of the knuckle 11 .

A nut 68 is screwed into a male screw formed at the tip of the protrusion 67 while the protrusion 67 is inserted through the through hole 11 h of the knuckle 11 and the through hole of the mounting portion 71 a of the hub bearing 70 . Thereby, the stator base portion 62 and the hub bearing 70 are fixed to the knuckle 11 . The shaft 41, the through hole 11e formed in the knuckle 11, and the hub bearing 70 are coaxial.

A shaft 41 is fixed to a cylindrical portion 72a that constitutes an inner ring 72 of the hub bearing 70. Since both ends of the shaft 41 are supported by the bearings 64 and the hub bearing 70, vibration of the shaft 41 due to rotation of the shaft 41 can be suppressed.

The brake device includes a disk-shaped brake disc 91 fixed to the shaft 41 and a brake caliper 92 fixed to the base portion 11 a of the knuckle 11 . The brake pads of the brake caliper 92 are hydraulically operated. By pressing the brake pad against the brake disc 91, a braking force due to friction is generated on the front wheel.

The brake disc 91 is also fixed to the flange portion 72b with bolts and nuts. As a result, vibration of the shaft 41 accompanying rotation of the shaft 41 can be suppressed.

The brake disc 91 is fixed to one end of the shaft 41 on the side opposite to the wheel with respect to the knuckle 11 . As a result, it is possible to reduce the size of the structure in the vehicle width direction around the front wheels and the brake device. In addition, the heat generated by pressing the brake pads against the brake disc 91 can be made less likely to be transmitted to the in-wheel motor 40 .

According to this embodiment detailed above, the following effects can be obtained.

The inner space of the wheel 30 surrounded by the rim portion 31 and the disk portion 32 accommodates the lower ball joint 16 that constitutes the steering portion. Therefore, the connecting portion between the lower arm connecting portion 11b that constitutes the knuckle 11 and the lower arm 12 can be arranged further outside in the vehicle width direction. As a result, the kingpin offset Lofs can be reduced. Therefore, the steering stability of the vehicle can be improved while effectively using the inner space of the wheel 30 as the space for arranging the connecting portion between the lower arm connecting portion 11b and the lower arm 12 .

The lower ball joint 16 and the upper ball joint 17 are arranged in the hollow portion 63 of the in-wheel motor 40 . As a result, the cavity 63 in the inner space of the wheel 30 is effectively used as a space for arranging the connecting portion between the lower arm connecting portion 11b and the lower arm 12 and the connecting portion between the upper arm connecting portion 11c and the upper arm 13, and the vehicle can be can enhance the steering stability.

Since the in-wheel motor 40 has an outer rotor type slotless structure, the hollow portion 63 can be easily enlarged, and the arrangement space of the lower ball joint 16 and the upper ball joint 17 can be widened.

The lower arm connecting portion 11b extends from the lower end of the knuckle 11 to the inner space of the wheel 30 outward in the vehicle width direction. As a result, the lower ball joint 16 can be arranged further outside in the vehicle width direction, and steering stability can be further enhanced.

The upper arm connecting portion 11c extends from the upper end portion of the knuckle 11 inward in the vehicle width direction. As a result, the kingpin axis LKG can be tilted further inward in the vehicle width direction, and the kingpin offset Lofs can be further reduced. As a result, the steering stability of the vehicle can be enhanced.

A lower arm 12 is composed of an arm base portion 12a arranged below the brake disc 91, an inclined arm portion 12c extending from the arm base portion 12a, and a lower connecting portion 12d extending from the inclined arm portion 12c. As a result, while the lower arm 12 does not interfere with the brake disc 91, the vehicle width direction outside end portion of the lower arm 12 can be arranged at the vehicle width direction outside position. As a result, the kingpin offset Lofs can be reduced.

<Second embodiment>
The second embodiment will be described below with reference to FIG. 8, focusing on differences from the first embodiment. In addition, in FIG. 8, the same code|symbol is attached|subjected about the structure same as the structure of 1st Embodiment for convenience.

As shown in FIG. 8, in this embodiment, the upper ball joint 117 is housed in the cavity 63 of the in-wheel motor 40. An upper arm 113 connected by an upper ball joint 117 has the same shape as the lower arm 12 . An upper arm connecting portion 111c connected by the upper ball joint 117 extends outward in the vehicle width direction from the upper end portion of the knuckle 11. As shown in FIG.

According to the embodiment described above, the connecting portion between the upper arm 113 and the upper arm connecting portion 111c can be shifted to the outer position in the vehicle width direction. As a result, the space inside the vehicle in the vehicle width direction can be expanded, for example, the space inside the vehicle can be expanded.

Incidentally, in the example shown in FIG. 8, the kingpin angle θ is set to 0 degree, but it is not limited to this.

<Other embodiments>
It should be noted that each of the above-described embodiments may be modified as follows.

· Instead of the bearing 64 in FIG. 2, a hub bearing 69 shown in FIG. 9 may be used. In addition, in FIG. 9, the same reference numerals are given to the same configurations as those shown in FIG. 2 for convenience.

The hub bearing 69 includes a cylindrical outer ring 69a, an inner ring, and a plurality of rolling elements 69d (for example, balls) arranged between the outer ring 69a and the inner ring. The inner ring has a cylindrical portion 69b having a diameter smaller than that of the outer ring 69a, and a flange portion 69c extending from one axial end of the cylindrical portion 69b in a direction intersecting (perpendicular to) the axial direction. The outer ring 69a is fixed to the stator base portion 62 with bolts. The shaft 41 is fixed to the cylindrical portion 69b, and the flat plate portion 53 and the disk portion 32 are fixed to the flange portion 69c.

· The inverter 80 may be built in the in-wheel motor 40 . In this case, the inverter 80 is electrically connected to the connector portion 66 of the in-wheel motor 40 . Also, the power line connected to the connector portion 66 serves as wiring that connects the inverter 80 and the power storage portion 82 .

· The hollow portion of the in-wheel motor 40 is not limited to the configuration in which it is provided for one round around the shaft 41 . For example, a hollow portion may be provided only in a portion of the stator base portion 62 that faces the lower ball joint 16 and the lower arm connecting portion 11b in the vehicle width direction.

· The suspension device is not limited to the wishbone type, and may be, for example, a multi-link or strut type suspension device. In the strut type, the kingpin axis is the axis passing through the central axis of the strut mount and the lower ball joint.

· Instead of fixing the flat plate portion 53 of the in-wheel motor 40 to the disk portion 32 of the wheel 30 , the magnet holding portion 51 of the in-wheel motor 40 may be fixed to the rim portion 31 .

· The rim portion of the wheel may be the magnet holding portion of the in-wheel motor, and the disc portion may be the flat plate portion. That is, the rotor of the in-wheel motor may serve as a wheel.

· The in-wheel motor may be an inner rotor type motor.

Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to those examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

Characteristic configurations extracted from each of the above-described embodiments will be described below.
[Configuration 1]
A wheel (30) having a rim portion (31) to which a tire (33) can be attached and a disk portion (32) provided on the outer side in the vehicle width direction of the rim portion;
an in-wheel motor (40) at least partially housed in a wheel inner space surrounded by the disk portion and the rim portion and rotating the wheel;
In a wheel unit in which the wheel is steerably attached to the vehicle body via a suspension device (10),
a knuckle (11) provided inside the wheel in the vehicle width direction;
a lower ball joint (16) through which the kingpin axis passes;
with
A lower arm connecting portion (11b) is provided at the lower end of the knuckle,
The lower ball joint rotatably connects a vehicle width direction outer end portion of a lower arm (12) constituting the suspension device and the lower arm connecting portion,
The wheel unit, wherein the lower ball joint is arranged in the inner space of the wheel.
[Configuration 2]
The wheel unit according to configuration 1, wherein the lower arm connecting portion extends outward in the vehicle width direction from the lower end portion of the knuckle to the inner space of the wheel.
[Configuration 3]
A hollow portion (63) recessed outward in the vehicle width direction is formed in a portion of the in-wheel motor that faces the lower ball joint and the lower arm connecting portion in the vehicle width direction and that is the inner portion of the in-wheel motor in the vehicle width direction. ,
The wheel unit according to configuration 2, wherein the lower ball joint is arranged in the hollow portion facing the lower ball joint and the lower arm connecting portion.
[Configuration 4]
The in-wheel motor is an outer rotor type motor comprising a rotor (50) and a stator (60) arranged radially inside the rotor,
The rotor is
a cylindrical magnet holder (51) housed in the wheel inner space;
a magnet unit (52) provided on the inner peripheral surface of the magnet holding portion and forming a plurality of magnetic poles with alternating polarities in the circumferential direction;
a shaft (41) extending in the vehicle width direction;
a connecting portion (53) provided at the outer end in the vehicle width direction of the magnet holding portion and housed in the wheel inner space for connecting the magnet holding portion and the shaft;
The stator has a cylindrical stator winding (61) arranged at a position facing the magnet unit in the radial direction of the stator,
The wheel unit according to configuration 3, wherein the cavity is formed between the stator windings and the shaft in the wheel inner space.
[Configuration 5]
The suspension device is an independent suspension type suspension device,
An upper arm connecting portion (11c, 111c) is provided at the upper end of the knuckle,
An upper ball joint (17, 117) through which the kingpin axis passes;
Any one of configurations 2 to 4, wherein the upper ball joint rotatably connects a vehicle width direction outer end portion of an upper arm (13, 113) constituting the suspension device and the upper arm connecting portion. Wheel unit described in .
[Configuration 6]
6. The wheel unit of configuration 5, wherein the intersection of the kingpin axis and the ground intersects the tread of the tire.
[Configuration 7]
The wheel according to configuration 5 or 6, wherein the lower arm connecting portion is arranged on the side of the rotation center axis between the rotation center axis of the rotor (50) constituting the in-wheel motor and the ground contact surface of the tire. unit.
[Configuration 8]
The wheel unit according to any one of configurations 5 to 7, wherein the upper arm connecting portion (11c) extends inward in the vehicle width direction from the upper end portion of the knuckle.
[Configuration 9]
A cavity recessed outward in the vehicle width direction ( 63) is formed,
The wheel unit according to any one of configurations 5 to 8, wherein the upper ball joint is arranged in the hollow portion facing the upper ball joint and the upper arm connecting portion.
[Configuration 10]
a wiring (81) electrically connected to the in-wheel motor and led out from a vehicle width direction inner portion of the in-wheel motor;
A recess (11f) recessed inward in the vehicle width direction is formed from a portion of the knuckle facing the in-wheel motor in the vehicle width direction to an end of the knuckle,
the wiring extends from a vehicle width direction inner portion of the in-wheel motor to the vehicle body side through the recess,
The wheel according to any one of configurations 1 to 9, comprising a guide portion (11g) that is provided to cover the recess from the outside in the vehicle width direction and prevents the wiring from protruding from the recess toward the wheel. unit.
[Configuration 11]
A shaft (41) connected to the rotor (50) constituting the in-wheel motor and extending in the vehicle width direction,
A through hole (11e) through which the shaft is inserted is formed in the center of the knuckle,
a bearing (70) provided in the knuckle and rotatably supporting the shaft;
4. The wheel unit according to any one of configurations 1 to 3, further comprising a brake disc (91) provided on the opposite end side of the knuckle from the rotor side, among both ends of the shaft. .
[Configuration 12]
The bearing has a cylindrical outer ring,
an inner ring having a tubular portion disposed radially inward of the outer ring and having a cylindrical shape with a diameter smaller than that of the outer ring, and a flange portion extending from one axial end of the tubular portion in a direction intersecting the axial direction;
a plurality of rolling elements arranged between the outer ring and the inner ring;
A hub bearing comprising
The outer ring is fixed with respect to the knuckle,
The shaft is fixed to the tubular portion,
12. Wheel unit according to configuration 11, wherein the brake disc is secured to the flange portion.
[Configuration 13]
A wheel (30) having a rim portion (31) to which a tire (33) can be attached and a disk portion (32) provided on the outer side in the vehicle width direction of the rim portion;
a knuckle (11) provided inside the wheel in the vehicle width direction;
a suspension device (10) steerably attaching the wheel to a vehicle body;
A lower ball for rotatably connecting a vehicle width direction outer end portion of a lower arm (12) constituting the suspension device to a lower arm connecting portion (11b) provided at a lower end portion of the knuckle, and through which a kingpin axis passes. applied to a vehicle comprising a joint (16) and
In the in-wheel motor that rotates the wheel,
The in-wheel motor is an outer rotor type motor comprising a rotor (50) and a stator (60) arranged radially inside the rotor,
The rotor is
a cylindrical magnet holding portion (51) housed in a wheel inner space surrounded by the disk portion and the rim portion;
a magnet unit (52) provided on the inner peripheral surface of the magnet holding portion and forming a plurality of magnetic poles with alternating polarities in the circumferential direction;
a shaft (41) extending in the vehicle width direction;
a connecting portion (53) provided at the outer end in the vehicle width direction of the magnet holding portion and housed in the wheel inner space for connecting the magnet holding portion and the shaft;
The stator has a cylindrical stator winding (61) arranged at a position facing the magnet unit in the radial direction of the stator,
A hollow portion (63) recessed outward in the vehicle width direction is formed in a portion of the stator that faces the lower ball joint and the lower arm connecting portion in the vehicle width direction, and is the inner portion of the stator in the vehicle width direction.
The cavity is formed between the stator winding and the shaft in the wheel inner space,
The in-wheel motor, wherein the lower ball joint is arranged in the cavity.

Claims

A wheel (30) having a rim portion (31) to which a tire (33) can be attached and a disk portion (32) provided on the outer side in the vehicle width direction of the rim portion;
an in-wheel motor (40) at least partially housed in a wheel inner space surrounded by the disk portion and the rim portion and rotating the wheel;
In a wheel unit in which the wheel is steerably attached to the vehicle body via a suspension device (10),
a knuckle (11) provided inside the wheel in the vehicle width direction;
a lower ball joint (16) through which the kingpin axis passes;
with
A lower arm connecting portion (11b) is provided at the lower end of the knuckle,
The lower ball joint rotatably connects a vehicle width direction outer end portion of a lower arm (12) constituting the suspension device and the lower arm connecting portion,
The wheel unit, wherein the lower ball joint is arranged in the inner space of the wheel.
The wheel unit according to claim 1, wherein the lower arm connecting portion extends outward in the vehicle width direction from the lower end of the knuckle to the inner space of the wheel.
A hollow portion (63) recessed outward in the vehicle width direction is formed in a portion of the in-wheel motor that faces the lower ball joint and the lower arm connecting portion in the vehicle width direction and that is the inner portion of the in-wheel motor in the vehicle width direction. ,
3. The wheel unit according to claim 2, wherein the lower ball joint is arranged in the hollow portion facing the lower ball joint and the lower arm connecting portion.
The in-wheel motor is an outer rotor type motor comprising a rotor (50) and a stator (60) arranged radially inside the rotor,
The rotor is
a cylindrical magnet holder (51) housed in the wheel inner space;
a magnet unit (52) provided on the inner peripheral surface of the magnet holding portion and forming a plurality of magnetic poles with alternating polarities in the circumferential direction;
a shaft (41) extending in the vehicle width direction;
a connecting portion (53) provided at the outer end in the vehicle width direction of the magnet holding portion and housed in the wheel inner space for connecting the magnet holding portion and the shaft;
The stator has a cylindrical stator winding (61) arranged at a position facing the magnet unit in the radial direction of the stator,
4. The wheel unit according to claim 3, wherein the cavity is formed between the stator windings and the shaft in the wheel inner space.
The suspension device is an independent suspension type suspension device,
An upper arm connecting portion (11c, 111c) is provided at the upper end of the knuckle,
An upper ball joint (17, 117) through which the kingpin axis passes;
5. Any one of claims 2 to 4, wherein the upper ball joint rotatably connects a vehicle width direction outer end portion of an upper arm (13, 113) constituting the suspension device and the upper arm connecting portion. A wheel unit as described above.
The wheel unit according to claim 5, wherein the intersection of the kingpin axis and the ground intersects the contact surface of the tire.
6. The wheel unit according to claim 5, wherein the lower arm connecting portion is arranged between the rotation center axis of the rotor (50) constituting the in-wheel motor and the contact surface of the tire on the rotation center axis side. .
The wheel unit according to claim 5, wherein the upper arm connecting portion (11c) extends inward in the vehicle width direction from the upper end portion of the knuckle.
A cavity recessed outward in the vehicle width direction ( 63) is formed,
6. The wheel unit according to claim 5, wherein the upper ball joint is arranged in the hollow portion facing the upper ball joint and the upper arm connecting portion.
a wiring (81) electrically connected to the in-wheel motor and led out from a vehicle width direction inner portion of the in-wheel motor;
A recess (11f) recessed inward in the vehicle width direction is formed from a portion of the knuckle facing the in-wheel motor in the vehicle width direction to an end of the knuckle,
the wiring extends from a vehicle width direction inner portion of the in-wheel motor to the vehicle body side through the recess,
5. The guide part (11g) provided so as to cover the recess from the outside in the vehicle width direction and prevents the wiring from protruding from the recess toward the wheel. wheel unit.
A shaft (41) connected to the rotor (50) constituting the in-wheel motor and extending in the vehicle width direction,
A through hole (11e) through which the shaft is inserted is formed in the center of the knuckle,
a bearing (70) provided in the knuckle and rotatably supporting the shaft;
The wheel according to any one of claims 1 to 3, further comprising a brake disc (91) provided on a side opposite to the rotor side with respect to the knuckle, among both ends of the shaft. unit.
The bearing has a cylindrical outer ring,
an inner ring having a tubular portion disposed radially inward of the outer ring and having a cylindrical shape with a diameter smaller than that of the outer ring, and a flange portion extending from one axial end of the tubular portion in a direction intersecting the axial direction;
a plurality of rolling elements arranged between the outer ring and the inner ring;
A hub bearing comprising
The outer ring is fixed with respect to the knuckle,
The shaft is fixed to the tubular portion,
12. A wheel unit according to claim 11, wherein said brake disc is fixed to said flange portion.
A wheel (30) having a rim portion (31) to which a tire (33) can be attached and a disk portion (32) provided on the outer side in the vehicle width direction of the rim portion;
a knuckle (11) provided inside the wheel in the vehicle width direction;
a suspension device (10) steerably attaching the wheel to a vehicle body;
A lower ball for rotatably connecting a vehicle width direction outer end portion of a lower arm (12) constituting the suspension device to a lower arm connecting portion (11b) provided at a lower end portion of the knuckle, and through which a kingpin axis passes. applied to a vehicle comprising a joint (16) and
In the in-wheel motor that rotates the wheel,
The in-wheel motor is an outer rotor type motor comprising a rotor (50) and a stator (60) arranged radially inside the rotor,
The rotor is
a cylindrical magnet holding portion (51) housed in a wheel inner space surrounded by the disk portion and the rim portion;
a magnet unit (52) provided on the inner peripheral surface of the magnet holding portion and forming a plurality of magnetic poles with alternating polarities in the circumferential direction;
a shaft (41) extending in the vehicle width direction;
a connecting portion (53) provided at the outer end in the vehicle width direction of the magnet holding portion and housed in the wheel inner space for connecting the magnet holding portion and the shaft;
The stator has a cylindrical stator winding (61) arranged at a position facing the magnet unit in the radial direction of the stator,
A hollow portion (63) recessed outward in the vehicle width direction is formed in a portion of the stator that faces the lower ball joint and the lower arm connecting portion in the vehicle width direction, and is the inner portion of the stator in the vehicle width direction.
The cavity is formed between the stator winding and the shaft in the wheel inner space,
The in-wheel motor, wherein the lower ball joint is arranged in the cavity.