Wheel assembly with in-wheel motor

• US 7,975,789 B2
• Filed: 08/10/2007
• Issued: 07/12/2011
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Murata, Satoshi
• Primary Examiner(s): VANAMAN, FRANK BENNETT
• Application Number:
  US12/097,290
• Publication Number:
  US 20080308330A1
• Time in Patent Office: 1,432 Days
• Field of Search: 180/65.1, 180/65.51, 180/65.6, 180/65.7, 310/83
• US Class Current: 180/65.51
• CPC Class Codes: B60G 2204/182 Electric motor on wheel support
• CPC Class Codes: B60G 2300/50 Electric vehicles; Hybrid vehicles
• CPC Class Codes: B60G 7/005 Ball joints B60G7/006 takes precedence; for steering linkage B62D7/16; ball joints per se F16C11/06
• CPC Class Codes: B60G 7/008 Attaching arms to unsprung part of vehicle B60G7/005, B60G7/006 take precedence
• CPC Class Codes: B60K 17/043 Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
• CPC Class Codes: B60K 17/046 with planetary gearing having orbital motion
• CPC Class Codes: B60K 2007/0038 the motor moving together with the wheel axle
• CPC Class Codes: B60K 2007/0061 the motor axle being parallel to the wheel axle
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel

Abstract

A wheel assembly with an in-wheel motor includes a motor for driving a wheel, which is arranged in the wheel; a reduction mechanism that reduces the rate of rotational output of the motor and transmits the resultant rotational output to the wheel; an oil tank in which oil collects; an oil pump that is driven by rotational output of the motor; and an oil flow path that leads oil from the oil pump to at least one of the motor and the reduction mechanism. The oil tank is arranged below the reduction mechanism, farther toward a vehicle inside in a vehicle width direction than a brake dust cover, and farther toward the vehicle outside in the vehicle width direction than a lower ball joint.

Claims

1. A wheel assembly with an in-wheel motor, comprising:

a motor for driving a wheel and which is arranged in the wheel;

a reduction mechanism which reduces the rate of rotational output of the motor and transmits the resultant rotational output to the wheel;

an oil tank in which oil collects;

an oil pump that is driven by rotational output of the motor;

an oil flow path that leads oil from the oil pump to at least one of the motor and the reduction mechanism;

a brake disc;

a brake dust cover that covers the brake disc from a vehicle inside in a vehicle width direction; and

a lower ball joint that is connected to a wheel-side end portion of a lower arm of a suspension arm,

wherein the oil tank is arranged below the reduction mechanism, closer to the vehicle inside than the brake dust cover, and closer to a vehicle outside in the vehicle width direction than the lower ball joint.

2. The wheel assembly with an in-wheel motor according to claim 1, wherein the brake disc includes a hat portion, and at least a portion of the oil tank is arranged inside the hat portion of the brake disc.

3. The wheel assembly with an in-wheel motor according to claim 1, wherein the oil tank is arranged on an inner radial side of an outer peripheral portion of the brake disc in the radial direction of the brake disc.

4. The wheel assembly with an in-wheel motor according to claim 1, wherein the oil tank includes a drain plug, and the drain plug is arranged offset in a vehicle longitudinal direction with respect to the lower ball joint.

5. The wheel assembly with an in-wheel motor according to claim 4, further comprising:

a knuckle,

wherein the oil tank includes a drain flow path for oil that includes an opening in the same position as the position where the lower ball joint fastens to the knuckle;

the drain flow path is formed in the knuckles; and

the drain plug also serves the fasten the lower ball joint to the knuckle.

6. The wheel assembly with an in-wheel motor according to claim 4, wherein the drain plug is arranged closer to the vehicle inside than the brake dust cover.

7. The wheel assembly with an in-wheel motor according to claim 4, wherein the drain plug is provided at the lowest position of the oil tank when suspension is unweighted.

8. The wheel assembly with an in-wheel motor according to claim 1, further comprising:

a tie rod ball joint that is connected to a wheel-side end portion of a tie rod,

wherein the oil tank includes a drain plug, and the drain plug is arranged offset in a vehicle longitudinal direction with respect to the tie rod ball joint.

9. The wheel assembly with an in-wheel motor according to claim 8, further comprising:

a knuckle,

wherein the oil tank includes a drain flow path for oil that includes an opening in the same position as the position where the lower ball joint fastens to the knuckle;

the drain flow path is formed in the knuckle; and

the drain plug also serves to fasten the lower ball joint to the knuckle.

10. The wheel assembly with an in-wheel motor according to claim 8, wherein the drain plug is arranged closer to the vehicle inside than the brake dust cover.

11. The wheel assembly with an in-wheel motor according to claim 8, wherein the drain plug is provided at the lowest position of the oil tank when suspension is unweighted.

12. The wheel assembly with an in-wheel motor according to claim 1, further comprising:

a knuckle,

wherein the oil tank includes a drain plug and a drain flow path for oil that includes an opening in the same position as the position where the lower ball joint fastens to the knuckle;

the drain flow path is formed in the knuckle; and

the drain plug also serves to fasten the lower ball joint to the knuckle.

13. The wheel assembly with an in-wheel motor according to claim 12, wherein the drain plug is arranged closer to the vehicle inside than the brake dust cover.

14. The wheel assembly with an in-wheel motor according to claim 12, wherein the drain plug is provided at the lowest position of the oil tank when suspension is unweighted.

15. The wheel assembly with an in-wheel motor according to claim 1, wherein the oil tank includes a drain plug, and the drain plug is arranged closer to the vehicle inside than the brake dust cover.

16. The wheel assembly with an in-wheel motor according to claim 1, wherein the oil tank includes a drain plug, and the drain plug is provided at the lowest position of the oil tank when suspension is unweighted.

17. The wheel assembly with an in-wheel motor according to claim 1, wherein the oil tank includes a filler plug, and the filler plug is arranged closer to the vehicle inside than the lower ball joint.

18. The wheel assembly with an in-wheel motor according to claim 1, further comprising:

a tie rod ball joint that is connected to a wheel-side end portion of a tie rod,

wherein the oil tank includes a filler plug, and the filler plug is arranged offset in a vehicle longitudinal direction with respect to the tie rod ball joint.

19. The wheel assembly with an in-wheel motor according to claim 1, further comprising:

a lower ball joint cover that covers the lower ball joint from above.

20. The wheel assembly with an in-wheel motor according to claim 1, wherein an output shaft of the motor is arranged offset upward and forward with respect to an axle center.