Drive device for four-wheel drive vehicle

Patent metadata

Field	Value
Publication number	US-11273706-B2
Application number	US-202016995007-A
Country	US
Kind code	B2
Filing date	Aug 17, 2020
Priority date	Sep 20, 2019
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A drive device includes a first clutch mechanism that couples or decouples power transmission systems for front and rear wheels, a first electric motor disposed on a front or rear wheel side and coupled to the first clutch mechanism, a second electric motor disposed on the other of the front and rear wheel sides and coupled to the first clutch mechanism, a second clutch mechanism that couples or decouples the first electric motor and front drive shafts, a planetary gear mechanism that distributes output of the first electric motor to the first and second clutch mechanisms, and a third clutch mechanism that limits a difference between a first rotational element that transmits the output of the first electric motor to the first clutch mechanism and a second rotational element that transmits the output of the first electric motor to the second clutch mechanism.

First claim

The invention claimed is:

1. A drive device for an electric-motor four-wheel drive vehicle, the drive device comprising:
a first clutch mechanism configured to perform switching between connection and disconnection of a power transmission system for front wheels and a power transmission system for rear wheels, wherein:
a propeller shaft couples the power transmission system for the front wheels and the power transmission system for the rear wheels;

a first electric motor disposed on one of a front wheel side or a rear wheel side with respect to the first clutch mechanism, the first electric motor being coupled to the first clutch mechanism, the front wheel side being a side on which the front wheels are provided and the rear wheel side being a side on which the rear wheels are provided;
a second electric motor disposed on the other of the front wheel side or the rear wheel side with respect to the first clutch mechanism, the second electric motor being coupled to the first clutch mechanism;
a second clutch mechanism configured to perform switching between connection and disconnection of the first electric motor and drive shafts for the front wheels;
a planetary gear mechanism configured to distribute output of the first electric motor to the first clutch mechanism and the second clutch mechanism;
a third clutch mechanism configured to limit a difference between a first rotational element in the planetary gear mechanism, the first rotational element being configured to transmit the output of the first electric motor to the first clutch mechanism, and a second rotational element in the planetary gear mechanism, the second rotational element being configured to transmit the output of the first electric motor to the second clutch mechanism; and
an orthogonal gear disposed on a power transmission route between the first rotational element and the propeller shaft.

2. The drive device according to claim 1 , wherein an output shaft of the first electric motor is disposed in parallel to the drive shafts for the front wheels and drive shafts for the rear wheels.

3. The drive device according to claim 1 , wherein an output shaft of the second electric motor is disposed in a direction orthogonal to the drive shafts for the front wheels and drive shafts for the rear wheels.

4. The drive device according to claim 2 , wherein an output shaft of the second electric motor is disposed in a direction orthogonal to the drive shafts for the front wheels and drive shafts for the rear wheels.

5. The drive device according to claim 1 , further comprising a controller configured, during a first travel mode where first requested torque is requested,
to engage the first clutch mechanism and the second clutch mechanism,
to disengage the third clutch mechanism,
to control the second electric motor to prevent the first rotational element from rotating, and
to control the output of the first electric motor, in accordance with the first requested torque.

6. The drive device according to claim 2 , further comprising a controller configured, during a first travel mode where first requested torque is requested,
to engage the first clutch mechanism and the second clutch mechanism,
to disengage the third clutch mechanism,
to control the second electric motor to prevent the first rotational element from rotating, and
to control the output of the first electric motor, in accordance with the first requested torque.

7. The drive device according to claim 5 , wherein the controller is configured, during a second travel mode where second requested torque lower than the first requested torque is requested,
to engage the second clutch mechanism and the third clutch mechanism,
to control the output of the first electric motor, and
to control or stop output of the second electric motor, in accordance with the second requested torque.

8. The drive device according to claim 6 , wherein the controller is configured, during a second travel mode where second requested torque lower than the first requested torque is requested,
to engage the second clutch mechanism and the third clutch mechanism,
to control the output of the first electric motor, and
to control or stop output of the second electric motor, in accordance with the second requested torque.

9. The drive device according to claim 5 , wherein the controller is configured, during a transition from the first travel mode to the second travel mode,
to engage the first clutch mechanism and the second clutch mechanism,
to allow an engagement force of the third clutch mechanism to gradually change, and
to allow the output of the first electric motor and the output of the second electric motor to gradually change to replace each other.

10. The drive device according to claim 6 , wherein the controller is configured, during a transition from the first travel mode to the second travel mode,
to engage the first clutch mechanism and the second clutch mechanism,
to allow an engagement force of the third clutch mechanism to gradually change, and
to allow the output of the first electric motor and the output of the second electric motor to gradually change to replace each other.

11. The drive device according to claim 1 , further comprising:
a differential mechanism coupled between the drive shafts for the front wheels;
a fourth clutch mechanism coupled to the drive shaft for a rear right wheel of the rear wheels, the fourth clutch mechanism being configured to adjust transmission of power to the rear right wheel; and
a fifth clutch mechanism coupled to the drive shaft for a rear left wheel of the rear wheels, the fifth clutch mechanism being configured to adjust transmission of power to the rear left wheel.

12. The drive device according to claim 2 , further comprising:
a differential mechanism coupled between the drive shafts for the front wheels;
a fourth clutch mechanism coupled to the drive shaft for a rear right wheel of the rear wheels, the fourth clutch mechanism being configured to adjust transmission of power to the rear right wheel; and
a fifth clutch mechanism coupled to the drive shaft for a rear left wheel of the rear wheels, the fifth clutch mechanism being configured to adjust transmission of power to the rear left wheel.

13. The drive device according to claim 1 , wherein
the first electric motor is disposed on the front wheel side with respect to the first clutch mechanism, and
the second electric motor is disposed on the rear wheel side with respect to the first clutch mechanism.

14. The drive device according to claim 2 , wherein
the first electric motor is disposed on the front wheel side with respect to the first clutch mechanism, and
the second electric motor is disposed on the rear wheel side with respect to the first clutch mechanism.

15. A drive device for an electric motor four wheel drive vehicle, the drive device comprising:
a first clutch mechanism configured to perform switching between connection and disconnection of a power transmission system for front wheels and a power transmission system for rear wheels, wherein:
a first electric motor configured to transmit an output torque of the first electric motor to one of a front wheel side or a rear wheel side with respect to the first clutch mechanism without passing through the first clutch mechanism, the first electric motor being coupled to one side of the first clutch mechanism, the front wheel side being a side on which the front wheels are provided and the rear wheel side being a side on which the rear wheels are provided;
a second electric motor configured to transmit an output

Assignees

• Subaru Corp

Inventors

• Inoh Takahito
• Imamura Naohiro
• Murakami Mamoru
• Mitsumoto Koki

Classifications

• B60K23/08

  for changing number of driven wheels {, for switching from driving one axle to driving two or more axles (B60K17/3515 takes precedence)} · CPC title

• B60K1/02 Primary

  comprising more than one electric motor · CPC title

• F16H48/08

  comprising bevel gears · CPC title

• B60K17/046

  with planetary gearing having orbital motion · CPC title

• B60K1/00

  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) · CPC title