DRIVE UNIT

• US 20170313182A1
• Filed: 04/28/2017
• Published: 11/02/2017
• Est. Priority Date: 04/28/2016
• Status: Active Grant

• Current Assignee: Alchemica Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Alchemica Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: ISONO, Hiroshi, SUGITANI, Nobuyoshi, KUBO, Aizoh
• Granted Patent: US 10,442,291 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 1/00 Arrangement or mounting of electrical propulsion units B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00; electric transmission arrangements B60K17/12; electric equipment or propulsion of electrically-propelled vehicles per se B60L; current-collectors for power supply lines of electrically-propelled vehicles B60L5/00
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 17/046 with planetary gearing having orbital motion
• CPC Class Codes: B60K 2023/043 Control means for varying left-right torque distribution, e.g. torque vectoring
• CPC Class Codes: B60K 23/04 for differential gearing
• CPC Class Codes: F16D 2121/20 using electromagnets
• CPC Class Codes: F16D 55/2262 the axial movement being guided by open sliding surfaces, e.g. grooves
• CPC Class Codes: F16D 65/18 adapted for drawing members together , e.g. for disc brakes
• CPC Class Codes: F16D 65/186 with full-face force-applying member, e.g. annular
• CPC Class Codes: F16H 1/28 with gears having orbital motion
• CPC Class Codes: F16H 48/36 characterised by intentionally generating speed difference between outputs

Abstract

A drive unit a drive unit which can prevent an occurrence of an unintentional relative rotation between the right and the left wheels is provided. The drive unit comprises: a first motor connected to the first driveshaft and a second motor connected to the second drive shaft; a first torque transmitting route between the first motor and the first drive shaft; a second torque transmitting route between the second motor and the second drive shaft; a first rotary member arranged in the first torque transmitting route; a second rotary member arranged in the second torque transmitting route; and a restriction device that restricts a differential rotation between the first rotary member and the second rotary member.

Claims

1. A drive unit, comprising:

a prime mover that propels a vehicle;

a first driveshaft that transmits torque from the prime mover to one of right and left driving wheels; and

a second drive shaft that transmits torque from the prime mover to other of the right and left driving wheels,

wherein the first drive shaft and the second drive shaft are allowed to be rotated by different torques,

the prime mover includes a first motor connected to the first driveshaft in a torque transmittable manner, and a second motor connected to the second drive shaft in a torque transmittable manner; and

the drive unit comprising;

a first torque transmitting route for transmitting torque from the first motor to the first drive shaft;

a second torque transmitting route for transmitting torque from the second motor to the second drive shaft;

a first rotary member that is arranged in the first torque transmitting route;

a second rotary member that is arranged in the second torque transmitting route; and

a restriction device that is interposed between the first rotary member and the second rotary member to restrict a differential rotation between the first rotary member and the second rotary member by changing a torque transmitted between the first rotary member and the second rotary member.

2. The drive unit as claimed in claim 1, further comprising:

a third rotary member arranged in the first torque transmitting route;

a fourth rotary member arranged in the second torque transmitting route; and

a lock device that stops rotation of any one of the third rotary member and the fourth rotary member.

3. The drive unit as claimed in claim 1,

wherein the restriction device includes a frictional engagement mechanism having a first rotary element rotated integrally with the first rotary member, a second rotary element rotated integrally with the second rotary member, and an actuator that selectively brings the second rotary element into contact to the first rotary element while controlling a contact pressure therebetween,

the first rotary element includes a first brake rotor,

the second rotary element includes a second brake rotor, and

the drive unit further comprising:

a first brake device that brings a first fixing member into contact to the first brake rotor to apply a braking torque to the first rotary element; and

a second braking device that brings a second fixing member into contact to the second brake rotor to apply a braking torque to the second rotary element.

4. The drive unit as claimed in claim 1,

wherein a rotational center axis of the first motor and a rotational center axis of the second motor are aligned coaxially with each other,

the first rotary member includes a first output shaft extending toward the second motor,

a first output gear is fitted onto a portion of the first output shaft extending toward the second motor,

a first gear train is formed of the first output gear and gears connected to the first driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the first output shaft,

the first torque transmitting route includes the first output shaft, the first output gear and the first gear train,

the second rotary member includes a second output shaft extending toward the first motor,

a second output gear is fitted onto a portion of the second output shaft extending toward the first motor,

a second gear train is formed of the second output gear and gears connected to the second driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the second output shaft,

the second torque transmitting route includes the second output shaft, the second output gear and the second gear train, and

the restriction device is interposed between laterally inner ends of the first output shaft and the second output shaft to restrict a differential rotation between the first output shaft and the second output shaft by changing a torque transmitted between the first output shaft and the second output shaft.

5. The drive unit as claimed in claim 1,

wherein a rotational center axis of the first motor and a rotational center axis of the second motor are aligned coaxially with each other,

the first driveshaft is connected to the first torque transmitting route in such a manner that the rotational center axis of an end portion thereof is aligned coaxially with the rotational center axis of the first motor, and

the second driveshaft is connected to the second torque transmitting route in such a manner that the rotational center axis of an end portion thereof is aligned coaxially with the rotational center axis of the second motor.

6. The drive unit as claimed in claim 5,

wherein the first output shaft of the first motor protrudes from both sides of the first motor,

a first planetary gear unit comprising at least three rotary elements is connected to a portion of the first output shaft protruding from the first motor in a direction opposite to the second motor,

the first driveshaft is connected to one of the rotary elements of the first planetary gear unit,

the first torque transmitting route includes the first output shaft and the first planetary gear unit,

the second output shaft of the second motor protrudes from both sides of the second motor,

a second planetary gear unit comprising at least three rotary elements is connected to a portion of the second output shaft protruding from the second motor in a direction opposite to the first motor,

the second driveshaft is connected to one of the rotary elements of the second planetary gear unit,

the second torque transmitting route includes the second output shaft and the second planetary gear unit, and

the restriction device is interposed between the portion of the first output shaft protruding from the first motor in a direction opposite to the second motor and the portion of the second output shaft protruding from the second motor in a direction opposite to the first motor, to restrict a differential rotation between the first output shaft and the second output shaft by changing a torque transmitted between the first output shaft and the second output shaft.

7. The drive unit as claimed in claim 2,

wherein the restriction device includes a frictional engagement mechanism having a first rotary element rotated integrally with the first rotary member, a second rotary element rotated integrally with the second rotary member, and an actuator that selectively brings the second rotary element into contact to the first rotary element while controlling a contact pressure therebetween,

the first rotary element includes a first brake rotor,

the second rotary element includes a second brake rotor, and

the drive unit further comprising:

a first brake device that brings a first fixing member into contact to the first brake rotor to apply a braking torque to the first rotary element; and

a second braking device that brings a second fixing member into contact to the second brake rotor to apply a braking torque to the second rotary element.

8. The drive unit as claimed in claim 2,

wherein a rotational center axis of the first motor and a rotational center axis of the second motor are aligned coaxially with each other,

the first rotary member includes a first output shaft extending toward the second motor,

a first output gear is fitted onto a portion of the first output shaft extending toward the second motor,

a first gear train is formed of the first output gear and gears connected to the first driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the first output shaft,

the first torque transmitting route includes the first output shaft, the first output gear and the first gear train,

the second rotary member includes a second output shaft extending toward the first motor,

a second output gear is fitted onto a portion of the second output shaft extending toward the first motor,

a second gear train is formed of the second output gear and gears connected to the second driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the second output shaft,

the second torque transmitting route includes the second output shaft, the second output gear and the second gear train, and

the restriction device is interposed between laterally inner ends of the first output shaft and the second output shaft to restrict a differential rotation between the first output shaft and the second output shaft by changing a torque transmitted between the first output shaft and the second output shaft.

9. The drive unit as claimed in claim 3,

wherein a rotational center axis of the first motor and a rotational center axis of the second motor are aligned coaxially with each other,

the first rotary member includes a first output shaft extending toward the second motor,

a first output gear is fitted onto a portion of the first output shaft extending toward the second motor,

a first gear train is formed of the first output gear and gears connected to the first driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the first output shaft,

the first torque transmitting route includes the first output shaft, the first output gear and the first gear train,

the second rotary member includes a second output shaft extending toward the first motor,

a second output gear is fitted onto a portion of the second output shaft extending toward the first motor,

a second gear train is formed of the second output gear and gears connected to the second driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the second output shaft,

the second torque transmitting route includes the second output shaft, the second output gear and the second gear train, and

the restriction device is interposed between laterally inner ends of the first output shaft and the second output shaft to restrict a differential rotation between the first output shaft and the second output shaft by changing a torque transmitted between the first output shaft and the second output shaft.

10. The drive unit as claimed in claim 7,

wherein a rotational center axis of the first motor and a rotational center axis of the second motor are aligned coaxially with each other,

the first rotary member includes a first output shaft extending toward the second motor,

a first output gear is fitted onto a portion of the first output shaft extending toward the second motor,

a first gear train is formed of the first output gear and gears connected to the first driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the first output shaft,

the first torque transmitting route includes the first output shaft, the first output gear and the first gear train,

the second rotary member includes a second output shaft extending toward the first motor,

a second output gear is fitted onto a portion of the second output shaft extending toward the first motor,

a second gear train is formed of the second output gear and gears connected to the second driveshaft in such a manner as to rotate around axes parallel to the rotational center axis of the second output shaft,

the second torque transmitting route includes the second output shaft, the second output gear and the second gear train, and

the restriction device is interposed between laterally inner ends of the first output shaft and the second output shaft to restrict a differential rotation between the first output shaft and the second output shaft by changing a torque transmitted between the first output shaft and the second output shaft.