Transmission with friction lauch mechanism

• US 20040224813A1
• Filed: 06/07/2004
• Published: 11/11/2004
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Carey, Clinton E., Borgerson, James B., Dusenberry, Donald L., Maguire, Joel M., Wittkopp, Scott H., Stevenson, Paul D., Biallas, Jeffrey J., Kienzle, Kent H., Winship, Richard A.
• Granted Patent: US 7,052,430 B2
• Time in Patent Office: Days
• US Class Current: 475/275
• CPC Class Codes: F16H 2200/0052 the gear ratios comprising six forward speeds
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/201 with three sets of orbital gears
• CPC Class Codes: F16H 2200/2097 comprising an orbital gear set member permanently connected to the housing, e.g. a sun wheel permanently connected to the housing
• CPC Class Codes: F16H 3/66 composed of a number of gear trains without drive passing from one train to another
• CPC Class Codes: F16H 3/666 with compound planetary gear units, e.g. two intermeshing orbital gears F16H3/663 takes precedence

Abstract

A powertrain includes a power transmission having an input shaft continuously connected directly between an engine and a planetary gear member of a first planetary gearset. Another member of the planetary gearset is selectively grounded by a torque transmitting mechanism to establish a reaction member during the launch of a vehicle incorporating the powertrain. The reaction member is established during both the lowest forward drive ratio and the reverse drive ratio. A third member of the planetary gearset transmits the torque from the input shaft, as modified by the planetary gearset, to other planetary gearsets in down stream power flow arrangement with the first planetary gearset.

Claims

1. (cancelled)

2. A power transmission for use in a powertrain having an engine for providing rotary power in a first direction to said power transmission, said power transmission comprising;

an input shaft continuously drivingly connected with the engine for rotation therewith;

an output shaft;

a first planetary gearset having a plurality of planetary gear members, said first planetary gearset being operably coupled with said input shaft;

a second planetary gearset having a plurality of planetary gear members, said second planetary gearset being drivingly interconnected with said output shaft;

a third planetary gearset having a plurality of planetary gear members, one of said gear members of said third planetary gearset being drivingly interconnected with one of said members of said first planetary gearset, another one of said gear members of said third planetary gearset being drivingly interconnected with one of said gear members of said second planetary gearset;

a first torque transmitting mechanism for selectively braking rotation of one of said gear members of said second planetary gearset to provide a forward launch ratio;

a second torque transmitting mechanism selectively operable to engage said third planetary gearset with said input shaft to provide a reverse launch ratio; and

a third torque transmitting mechanism for selectively braking rotation of one of said planetary gear members of said third planetary gearset to serve as a reaction member in said forward launch ratio wherein said third torque transmitting mechanism includes a one-way clutch coupled in series with a plate clutch.

3. The power transmission of claim 2 further including a fourth torque transmitting mechanism for selectively braking rotation of one of said planetary gear members of said third planetary gearset.

4. The power transmission of claim 3 further including a fifth torque transmitting mechanism selectively operable to engage one of said planetary gear members of said third planetary gearset with said input shaft.

5. The power transmission of claim 2 wherein said one-way clutch is operable in one of a released mode where torque is not transmitted by said one-way clutch and a locked mode where torque is transmitted in one direction by said one-way clutch, said power transmission further including an actuator for shifting said one-way clutch between its released and locked modes.

6. The power transmission of claim 2 wherein each of said first, second and third planetary gearsets includes first, second and third gear members.

7. The power transmission of claim 6 wherein said first gear member of said first planetary gearset is operably coupled to said input shaft and said second member of said first planetary gearset is operably coupled with said third member of said second planetary gearset.

8. The power transmission of claim 7 wherein said third member of said first planetary gearset is operably coupled to said second member of said third planetary gearset.

9. The power transmission of claim 2 wherein said one of said planetary gear members of said third planetary gearset serves as a reaction member in said reverse launch ratio.

10. The power transmission of claim 2 wherein said one-way clutch is a selectively operable bi-directional one-way clutch.

11. The power transmission of claim 10 wherein said selectively operable bi-directional one-way clutch includes a plurality of rollers retained by a cage.

12. The power transmission of claim 11 further including a friction plate engageable with said cage, wherein rotation of said friction plate rotates said cage to transfer torque through said one-way clutch.

13. The power transmission of claim 12 further including an actuator having an axially moveable piston selectively engageable with said friction plate, said friction plate being rotated into engagement with said cage while said friction plate is engaged with a rotating member.

14. The power transmission of claim 10 wherein said selectively operable bi-directional one-way clutch includes a first cam plate and a second cam plate, wherein axial movement of said first cam plate causes said second cam plate to rotate.

15. The power transmission of claim 14 wherein said first cam plate includes a plurality of driving cam faces selectively engageable with a plurality of driven cam faces positioned on said second cam plate.

16. The power transmission of claim 15 further including a biasing member urging said driving cam faces away from said driven cam faces.

17. The power transmission of claim 16 wherein rotation of said second cam plate switches said one-way clutch into a torque transmitting mode.

18. A power transmission for use in a powertrain having an engine for providing rotary power to the transmission, said transmission comprising:

an input shaft continuously connected with the engine for rotation therewith;

a first planetary gearset having a first member driven by said input shaft, a second member, and a third member;

a second planetary gearset having a third member driven by said second member of said first planetary gearset, a second member driving said output shaft, and a first member;

a third planetary gearset having a third member driven by said second member of said second planetary gearset, a second member driven by said third member of said first planetary gearset and a first member;

a first torque transmitting mechanism that is operable to selectively engage said first member of said third planetary gearset for rotation with said input shaft;

a second torque transmitting mechanism that is selectively operable to engage said third member of said first planetary gearset for rotation with said input shaft;

a third torque transmitting mechanism for selectively braking rotation of said first member of said third planetary gearset;

a fourth torque transmitting mechanism for selectively braking rotation of said second member of said third planetary gearset, said fourth torque transmitting mechanism including a one-way clutch coupled in series with a plate clutch; and

a fifth torque transmitting mechanism for selectively braking rotation of said first member of said second planetary gearset.

19. The power transmission of claim 18 wherein said one-way clutch is operable in either of a released mode and a locked mode, said power transmission further including an actuator for shifting said one-way clutch between its released and locked modes.

20. The power transmission of claim 19 wherein said actuator includes an axially moveable piston operable to selectively engage a rotatable friction plate, wherein rotation of said friction plate switches said one-way clutch between said released and said locked modes.

21. The power transmission of claim 20 wherein said one-way clutch is bi-directional and selectively operable to transfer torque during a reverse drive ratio launch and a forward drive ratio launch.

22. The power transmission of claim 21 wherein said one-way clutch includes an inner race, an outer race and a plurality of rollers retained by a cage.

23. The power transmission of claim 22 wherein said friction plate is operable to rotate said cage to engage said rollers with said inner race and said outer race thereby shifting said one-way clutch into said locked mode.

24. The power transmission of claim 21 wherein said one-way clutch is fully engaged prior to controlled engagement of said plate clutch during said reverse drive ratio launch and said first forward ratio launch.

25. The power transmission of claim 24 wherein said one-way clutch transfers torque during launch in said first forward drive ratio and overruns during operation in a second forward drive ratio.

26. The power transmission of claim 18 wherein said one-way clutch includes a uni-directional overrunning clutch, said power transmission further including a sixth torque transmitting mechanism for selectively braking rotation of said third member of said third planetary gearset during a reverse gear ratio launch, said sixth torque transmitting mechanism being positioned in parallel with said fifth torque transmitting mechanism.

27. The power transmission of claim 26 wherein said uni-directional overrunning clutch transfers torque during a forward drive ratio launch.

28. The power transmission of claim 27 wherein said uni-directional overrunning clutch overruns during operation in a second forward drive ratio.

29. The power transmission of claim 18 wherein said one-way clutch is a selectively operable bi-directional one-way clutch.

30. The power transmission of claim 29 wherein said selectively operable bi-directional one-way clutch includes a first cam plate and a second cam plate, wherein axial movement of said first cam plate causes said second cam plate to rotate.

31. The power transmission of claim 30 wherein said first cam plate includes a plurality of driving cam faces selectively engageable with a plurality of driven cam faces positioned on said second cam plate.

32. The power transmission of claim 31 further including a biasing member urging said driving cam faces away from said driven cam faces.

33. The power transmission of claim 32 wherein rotation of said second cam plate switches said one-way clutch into a torque transmitting mode.