Twin clutch automated transaxle with motor/generator synchronization

• US 20020088290A1
• Filed: 01/10/2001
• Published: 07/11/2002
• Est. Priority Date: 01/10/2001
• Status: Active Grant

• Current Assignee: New Venture Gear, Incorporated (Magna International Incorporated)
• Original Assignee: New Venture Gear, Incorporated (Magna International Incorporated)
• Inventors: Bowen, Thomas C.
• Granted Patent: US 6,499,370 B2
• Time in Patent Office: Days
• US Class Current: 74/335
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/36 characterised by the transmission gearings
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/113 with two input flow paths, e.g. double clutch transmission selection of one of the torque flow paths by the corresponding input clutch
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60Y 2400/4242 of dry type
• CPC Class Codes: B60Y 2400/428 Double clutch arrangements; Dual clutches
• CPC Class Codes: F16H 2061/0422 by an electric machine, e.g. by accelerating or braking the input shaft
• CPC Class Codes: F16H 2061/0433 by torque supply with an electric motor
• CPC Class Codes: F16H 2061/0474 by smoothing engagement or release of positive clutches; Methods or means for shock free engagement of dog clutches for tooth butt situations F16H2061/047
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/126 using an electric drive
• CPC Class Codes: F16H 61/0403 Synchronisation before shifting
• CPC Class Codes: F16H 61/688 with two inputs, e.g. selection of one of two torque-flow paths by clutches
• CPC Class Codes: Y10T 74/19228 Multiple concentric clutch shafts
• CPC Class Codes: Y10T 74/19251 Control mechanism
• CPC Class Codes: Y10T 74/19284 : Meshing assisters
• CPC Class Codes: Y10T 74/194 : Selective

Abstract

An automated twin-clutch multi-speed transmission is disclosed which functions to transfer power from the engine to one or more drivelines of a motor vehicle. The transmission includes a first engine clutch operable to establish a releasable drive connection between the engine and a first input shaft, a first motor/generator connected to the first input shaft, a second engine clutch operable to establish a releasable drive connection between the engine and a second input shaft, a second motor/generator connected to the second input shaft, an output shaft adapted to transfer power to the driveline, and a geartrain for selectively establishing a plurality of forward and reverse speed ratio drive connections between the input shafts and the output shaft. The transmission further includes power-operated dog clutches for selectively engaging constant-mesh gearsets associated with the geartrain, and a transmission controller for controlling coordinated actuation of the first and second engine clutches, the first and second motor/generators, and the power-operated dog clutches to permit non-power interrupted (“powershift”) sequential gear changes automatically without input from the vehicle operator.

Claims

1. A twin-clutch transmission for use in a motor vehicle having an engine and a driveline, comprising:

an output shaft adapated for connection to the driveline and having an output gear fixed thereto;

a first input shaft rotatably supporting a first speed gear meshed with said output gear;

a first engine clutch operable for establishing a releasable drive connection between the engine and said first input shaft;

a first shift clutch operable for releaseably coupling said first speed gear to said first input shaft to establish a drive connection between said first input shaft and said output shaft;

a second input shaft rotatably supporting a second speed gear meshed with said output gear;

a second engine clutch operable for establishing a releasable drive connection between the engine and said second input shaft;

a second shift clutch operable for releasably coupling said second speed gear to said second input shaft to establish a drive connection between said second input shaft and said output shaft;

a first motor/generator connected to said first input shaft;

a second motor/generator connected to said second input shaft; and

a controller for controlling actuation of said first and second motor/generators.

2. The twin-clutch transmission of claim 1 further comprising:

a first electric actuator controlling actuation of said first engine clutch; and

a second electric actuator controlling actuation of said second engine clutch;

wherein said controller controls actuation of said first and second electric actuators.

3. The twin-clutch transmission of claim 2 wherein said first and second shift clutchs are electrically-actuated dog clutches controlled by said controller.

4. The twin-clutch transmission of claim 1 wherein first motor/generator has a first rotor adapted to drive or be driven by said first input shaft, said second motor/generator has a second rotor adapted to drive or be driven by said second input shaft, whereby when said first input shaft is released from driven connection with the engine and said first shift clutch is disengaged, said first motor/generator is actuated to synchronize the rotary speed of said first input shaft to that of said first speed gear driven by said output gear.

5. The twin-clutch transmission of claim 1 further comprising:

a second output gear fixed to said output shaft;

a third speed gear rotatably supported on said first input shaft and meshed with said second output gear; and

a fourth speed gear rotatably supported on said second input shaft and meshed with said second output gear;

wherein said first shift clutch is operable for releasably coupling said third speed gear to said first input shaft, and said second shift clutch is operable for releasably coupling said fourth speed gear to said second input shaft.

6. The twin-clutch transmission of claim 1 wherein the driveline is a front driveline and said output shaft drives a final drive unit including a differential and left and right front axleshafts.

7. The twin-clutch transmission of claim 1 wherein said first and second engine clutches and said first and second shift clutches are electrically-actuated devices controlled by said controller for automatically shifting between a first gear ratio established by said first speed gear and a second gear ratio established by said second speed gear.

8. The twin-clutch transmission of claim 7 wherein said first and second shift clutches are electrically-actuated dog clutches.

9. The twin-clutch transmission of claim 1 further comprising a transfer shaft releasably driven by said first engine clutch, and a power transfer assembly coupling said transfer shaft to said first input shaft.

10. The twin-clutch transmission of claim 9 wherein said power transfer assembly includes a first sprocket fixed to said first input shaft, a second sprocket fixed to said transfer shaft, and a chain meshed with said first and second sprockets.

11. A twin-clutch transmission for use in a motor vehicle having an engine and a driveline, comprising:

an output shaft adapted for connection to the driveline;

a first input shaft;

a second input shaft;

a first engine clutch operable for establishing a releasable drive connection between the engine and said first input shaft;

a second engine clutch operable for establishing a releasable drive connection between the engine and said second input shaft;

a geartrain including first and second output gears fixed to said output shaft, a first speed gear supported on said first input shaft and meshed with said first output gear, a second speed gear supported on said second input shaft and meshed with said first output gear, a third speed gear supported on said first input shaft and meshed with said second output gear, and a fourth speed gear supported on said second input shaft and meshed with said second output gear;

a first shift clutch operable for releasable coupling said first and third speed gears to said first input shaft;

a second shift clutch operable for releasably coupling said second and fourth speed gears to said second input shaft;

a first motor/generator connected to said first input shaft;

a second motor/generator connected to said second input shaft; and

a transmission control system for controlling coordinated actuation of said first and second engine clutches, said first and second shift clutches and said first and second motor/generators to cause powershift sequential gear shifts, such that when one of said first and second input shafts is released from driven connection with the engine, said motor/generator associated with the released one of said first and second input shafts is actuated to synchronize the rotary speed of the released one of said first and second input shaft with said output shaft.

12. The twin-clutch transmission of claim 11 wherein the driveline is a front driveline and said output shaft drives a final drive unit including a differential and left and right front axleshafts.

13. The twin-clutch transmission of claim 11 wherein said first and second engine clutches and said first and second shift clutches are power-operated devices controlled by a controller for automatically shifting between a first gear ratio established by said first speed gear, a second gear ratio established by said second speed gear, a third gear ratio established by said third speed gear, and a fourth gear ratio established by said fourth speed gear.

14. The twin-clutch transmission of claim 12 wherein said first and second shift clutches are electrically-actuated dog clutches.

15. The twin-clutch transmission of claim 13 wherein said first and second engine clutches are electrically-actuated by first and second electromagnetic solenoids controlled by said controller.

16. The twin-clutch transmission of claim 11 wherein first motor/generator has a first rotor adapted to drive or be driven by said first input shaft, said second motor/generator has a second rotor adapted to drive or be driven by said second input shaft, whereby when said first input shaft is released from driven connection with the engine and said first shift clutch is disengaged, said first motor/generator is actuated to synchronize the rotary speed of said first input shaft to that of said first speed gear driven by said output gear.

17. The twin-clutch transmission of claim 11 further comprising a transfer shaft releasably driven by said first engine clutch, and a power transfer assembly coupling said transfer shaft to said first input shaft.

18. The twin-clutch transmission of claim 17 wherein said power transfer assembly includes a first sprocket fixed to said first input shaft, a second sprocket fixed to said transfer shaft, and a chain meshed with said first and second sprockets.