Hybrid Transmission with Disconnect Clutch and Method of Starting an Engine Using Same

• US 20100087290A1
• Filed: 10/06/2008
• Published: 04/08/2010
• Est. Priority Date: 10/06/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Schoenek, Norman, Holmes, Alan G., Swales, Shawn H., Maguire, Joel M.
• Granted Patent: US 8,123,656 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/383 One-way clutches or freewheel devices
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/026 of lock-up clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A hybrid transmission is provided with a motor and a torque-transfer device is operable to transfer torque from the motor to a transmission input member upstream in power flow from the transmission gearing arrangement. The torque transfer device may be a fluid coupling, such as a torque converter, including a torque converter lock-up clutch. In other embodiments, the torque transfer device is a launch clutch that may be either a wet clutch engagable via pressurized transmission fluid, or a dry clutch, such as used in a manual transmission. A disconnect clutch is selectively engagable to operatively connect an engine connection member with the motor to permit the motor to start the engine, such as after a stop. Many embodiments of the transmission include a one-way clutch arranged in parallel with the disconnect clutch. A method of starting the engine using such a transmission is also provided.

Claims

1. A hybrid transmission for use with an engine, comprising:

an engine connection member configured for connection with the engine;

an electric motor;

a transmission gearing arrangement;

a transmission input member connected with the transmission gearing arrangement;

a torque transfer device controllable to transfer torque from the motor to the transmission input member upstream in power flow from the mechanical transmission gearing arrangement; and

a disconnect clutch selectively engagable to operatively connect the engine connection member with the motor to permit the motor to start the engine.

2. The hybrid transmission of claim 1, further comprising:

a one-way clutch having a first rotatable element continuously connected for rotation with the engine connection member and a second rotatable element continuously connected for rotation with the motor and configured to overrun when the second rotatable element rotates faster than the first rotatable element;

wherein the disconnect clutch is arranged in parallel with the one-way clutch;

the one-way clutch thereby carrying torque when the engine powers the transmission and overrunning when the motor powers the transmission.

3. The hybrid transmission of claim 1, wherein the torque transfer device is a fluid coupling.

4. The hybrid transmission of claim 1, wherein the torque transfer device is a clutch directly connecting the motor with the transmission input member;

and wherein the hybrid transmission does not include a fluid coupling.

5. The hybrid transmission of claim 4, wherein the torque transfer device is a wet clutch.

6. The hybrid transmission of claim 1, wherein the disconnect clutch is a dry, electro-mechanically actuated clutch.

7. The hybrid transmission of claim 1, wherein the disconnect clutch is a wet clutch selectively engagable via pressurized transmission fluid.

8. The hybrid transmission of claim 7, wherein the input member is hollow;

and further comprising;

a tubular member coaxial with and inside of the transmission input member and sealed therewith to define therewith a channel for transporting pressurized transmission fluid to the torque transfer device.

9. The hybrid transmission of claim 1, further comprising:

inner and outer hub members coaxial with the input member;

wherein the motor includes a rotor and a stator;

wherein the rotor is concentric with and surrounds the stator and is supported for rotation on the inner hub member;

wherein the engine is operatively connected with the outer hub member; and

wherein selective engagement of the disconnecting clutch connects the inner and outer hub members.

10. The hybrid transmission of claim 9, wherein the inner hub member is perforated to permit transmission oil flow past the motor and torque transfer device for cooling and lubrication thereof.

11. The hybrid transmission of claim 1, further comprising:

a damping mechanism connecting the engine with the torque transfer device.

12. The hybrid transmission of claim 11, wherein the disconnect clutch connects the motor to the damping mechanism, thereby operatively connecting the motor to the engine connection member.

13. The hybrid transmission of claim 11, wherein the disconnect clutch connects the motor for common rotation with the engine connection member and bypasses the damping mechanism.

14. The hybrid transmission of claim 1, wherein the motor is controllable to operate as a generator.

15. The hybrid transmission of claim 1, further comprising:

a transmission pump continuously operatively connected with the motor and driven by the motor.

16. The hybrid transmission of claim 1, wherein the transmission is characterized by an absence of any additional motor operatively connected with the mechanical transmission gearing arrangement.

17. The hybrid transmission of claim 1, wherein the motor is not operatively connected for torque transfer to the transmission gearing arrangement other than by the torque transfer device.

18. A hybrid transmission for use with an engine, comprising:

an engine connection member configured for connection with the engine;

an electric motor;

a mechanical transmission gearing arrangement;

a transmission input member;

a fluid coupling operable to transfer torque from the motor to the transmission input member upstream in power flow from the transmission gearing arrangement;

a disconnect clutch selectively engagable to operatively connect the engine connection member with the motor to permit the motor to start the engine.

a one-way clutch having a first rotatable element continuously connected for rotation with the engine connection member and a second rotatable element continuously connected for rotation with the motor and configured to overrun when the second rotatable element rotates faster than the first rotatable element;

wherein the disconnect clutch is arranged in parallel with the one-way clutch;

the one-way clutch thereby carrying torque when the engine powers the transmission and overrunning when the motor powers the transmission;

a damping mechanism connecting the engine with the fluid coupling; and

a transmission pump continuously operatively connected with the fluid coupling and driven by the motor.

19. A method of starting an engine connected with a hybrid transmission comprising:

providing stored electrical power from a battery connected with a motor to the motor to run a transmission pump connected with the motor to thereby pressurize fluid;

engaging selected ratio clutches connected with a transmission gearing arrangement using the pressurized fluid;

powering the transmission through a torque transfer device via the motor;

monitoring a charge level of the battery; and

engaging a disconnect clutch between the motor and the engine when the monitored battery charge level falls to a predetermined level, thereby starting the engine.

20. The method of claim 19, wherein the engine transfers torque through a one-way clutch arranged in parallel with the disconnect clutch and through the torque transfer device to the transmission gearing arrangement when engine speed is at least at motor speed;

wherein the one-way clutch overruns when the motor speed is greater than engine speed; and

further comprising;

disengaging the disconnect clutch when the engine transfers torque through the one-way clutch.