Electric drive unit and powertrain system incorporating the same

Patent metadata

Field	Value
Publication number	US-9566857-B1
Application number	US-201514830327-A
Country	US
Kind code	B1
Filing date	Aug 19, 2015
Priority date	Aug 19, 2015
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

An electric drive unit for a powertrain system including first and second drivelines and a primary propulsion system for translating rotational torque to the first driveline. A motor acts to generate rotational torque and a pinion is disposed in selective communication therewith. A differential is interposed between the pinion and the second driveline of for splitting torque therebetween. A first planetary is disposed between the motor and pinion, and a second planetary is disposed between the first planetary and pinion. A dog clutch interposed between the pinion and the planetaries is movable between a first position wherein torque from the motor is translated through the first planetary and the dog clutch to drive the second driveline at a first drive ratio, and a second position wherein torque from the motor is translated through both planetaries and the dog clutch to drive the second driveline at a second drive ratio.

First claim

What is claimed is:

1. An electric drive unit for use in a powertrain system including first and second drivelines and a primary propulsion system for translating rotational torque to the first driveline, the second driveline including a pair of wheels, said electric drive unit comprising:
an electric motor that acts to selectively generate rotational torque;
a pinion disposed in selective rotational communication with said electric motor;
a differential interposed in torque translating relationship between said pinion and the second driveline of the powertrain system for splitting rotational torque between said pinion and the wheels of the second driveline;
a first planetary gearset disposed in selective torque translating relationship between said electric motor and said pinion;
a second planetary gearset disposed in selective torque translating relationship between said first planetary gearset and said pinion; and
a dog clutch assembly interposed in torque translating relationship between said pinion and said planetary gearsets, wherein said dog clutch assembly is movable between a first position wherein rotational torque from said electric motor is translated through said first planetary gearset and said dog clutch assembly to said pinion so as to drive the wheels of the second driveline at a first predetermined drive ratio, and a second position wherein rotational torque from said electric motor is translated through both of said planetary gearsets and said dog clutch assembly to said pinion so as to drive the wheels of the second driveline at a second predetermined drive ratio.

2. The electric drive unit as set forth in claim 1 , further including a common ring gear supporting said first planetary gearset and said second planetary gearset.

3. The electric drive unit as set forth in claim 1 , wherein said dog clutch assembly is selectively movable to a third position wherein rotational torque is interrupted between said electric motor and said pinion.

4. The electric drive unit as set forth in claim 1 , further including an actuator for selectively moving said dog clutch assembly between said first position and said second position.

5. The electric drive unit as set forth in claim 1 , wherein said first planetary gearset includes a first sun gear, a plurality of first planet gears disposed in meshing relationship with said first sun gear, and a first carrier supporting said first planet gears; and wherein said first carrier rotates concurrently with said pinion when said dog clutch assembly is in said first position.

6. The electric drive unit as set forth in claim 5 , wherein said first sun gear is operatively attached to said electric motor.

7. The electric drive unit as set forth in claim 5 , wherein said second planetary gearset includes a second sun gear, a plurality of second planet gears disposed in meshing relationship with said second sun gear, and a second carrier supporting said second planet gears; and wherein said second carrier rotates concurrently with said pinion when said dog clutch assembly is in said second position.

8. The electric drive unit as set forth in claim 7 , wherein said first carrier of said first planetary gearset is integrally formed with said second sun gear of said second planetary gearset.

9. The electric drive unit as set forth in claim 1 , wherein said differential has a ring supported in rotational communication with said pinion.

10. The electric drive unit as set forth in claim 9 , wherein said ring and said pinion define a differential reduction gear ratio, said first planetary gearset defines a first reduction gear ratio, and said second planetary gearset defines a second gear reduction ratio; and
wherein said first predetermined drive ratio is equal to the product of said differential reduction gear ratio and said first reduction gear ratio; and said second predetermined drive ratio is equal to the product of said differential reduction gear ratio, said first reduction gear ratio, and said second reduction gear ratio.

11. The electric drive unit as set forth in claim 10 , wherein said first reduction gear ratio is equal to said second reduction gear ratio.

12. A powertrain system comprising:
a first driveline having a first pair of wheels;
a second driveline having a second pair of wheels;
a primary propulsion system that acts to generate and translate a first rotational torque only to said first pair of wheels of said first driveline;
an auxiliary propulsion system that acts to generate and translate a second rotational torque only to said second pair of wheels of said second driveline, said auxiliary propulsion system including an electric drive unit having:
an electric motor that acts to selectively generate a third rotational torque;
a pinion disposed in selective rotational communication with said electric motor;
a differential interposed in torque translating relationship between said pinion and said second pair of wheels for splitting a fourth rotational torque between said pinion and said second pair of wheels;
a first planetary gearset disposed in selective torque translating relationship between said electric motor and said pinion;
a second planetary gearset disposed in selective torque translating relationship between said first planetary gearset and said pinion; and
a dog clutch assembly interposed in torque translating relationship between said pinion and said first planetary gearset and said second planetary gearset, wherein said dog clutch assembly is movable between a first position wherein the third rotational torque from said electric motor is translated through said first planetary gearset and said dog clutch assembly to said pinion so as to drive said second pair of wheels at a first predetermined drive ratio, and a second position wherein the third rotational torque from said electric motor is translated through both of said planetary gearsets and said dog clutch assembly to said pinion so as to drive said second pair of wheels at a second predetermined drive ratio.

13. The powertrain system as set forth in claim 12 , wherein said auxiliary propulsion system includes a battery in electrical communication with said electric motor of said electric drive unit.

14. The powertrain system as set forth in claim 12 , wherein said primary propulsion system includes an internal combustion engine.

15. The powertrain system as set forth in claim 12 , wherein said primary propulsion system is further defined as another electric drive unit.

Assignees

• Borgwarner Inc

Inventors

• Pritchard Larry
• Kopp Thaddeus

Classifications

• B60K6/50 Primary

  Architecture of the driveline characterised by arrangement or kind of transmission units · CPC title

• B60K17/16

  of differential gearing · CPC title

• B60Y2400/73

  Planetary gearings · CPC title

• Y10S903/911

  with two or more gear sets · CPC title

• B60K6/48

  Parallel type · CPC title