Transmission

• US 6,827,664 B2
• Filed: 11/15/2002
• Issued: 12/07/2004
• Est. Priority Date: 11/15/2001
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Borgerson, James B., Dusenberry, Donald L., Maguire, Joel M., Kienzle, Kent H., Carey, Clinton E., Stevenson, Paul D., Biallas, Jeffrey J.
• Primary Examiner(s): Bonck, Rodney H.
• Assistant Examiner(s): Le, David D.
• Application Number:
  US10/295,120
• Publication Number:
  US 20030119623A1
• Time in Patent Office: 753 Days
• Field of Search: 475/275, 475/276, 475/278, 475/281, 475/292
• 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. 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 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 continuously connected 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, said third planetary gearset being drivingly interconnected with said output shaft;

a first torque transmitting mechanism selectively operable to engage said first planetary gearset with said second planetary gearset to provide a forward drive ratio;

a second torque transmitting mechanism selectively operable to engage said first planetary gearset with said third planetary gearset to provide a reverse drive ratio; and

a third torque transmitting mechanism for selectively braking rotation of at least one of said planetary gear members of said second planetary gearset and said third planetary gearset to serve as a reaction member in both said forward drive ratio and said reverse drive ratio.

2. The power transmission according to claim 1, further comprising:

a fourth torque transmitting mechanism selectively operable to engage said second planetary gearset for rotation with said input shaft; and

a fifth torque transmitting mechanism for selectively braking rotation of said third planetary gearset.

3. The power transmission according to claim 1 wherein said third torque transmitting mechanism is a multi-plate clutch mechanism.

4. The power transmission according to claim 1 wherein said third torque transmitting mechanism is a band-type brake assembly.

5. The power transmission according to claim 1 wherein said first planetary gearset, said second planetary gearset, and said third planetary gearset each includes a first member, a second member, and a third member.

6. The power transmission according to claim 5 wherein said second member of said second planetary gearset includes a meshed pair of pinion gears.

7. The power transmission according to claim 5, further comprising a housing, and wherein said third member of said first planetary gearset is fixedly coupled to said housing.

8. The power transmission according to claim 5 wherein said third member of said second planetary gearset and said third member of said third planetary gearset are formed as a single unitary member.

9. The power transmission according to claim 8, wherein said single unitary member is a ring gear.

10. 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 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 continuously connected 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, said third planetary gearset being drivingly interconnected with said output shaft;

a first torque transmitting mechanism selectively operable to engage said first planetary gearset with said second planetary gearset to provide a forward drive ratio;

a second torque transmitting mechanism selectively operable to engage said first planetary gearset with said third planetary gearset to provide a reverse drive ratio;

a third torque transmitting mechanism for selectively braking rotation of at least one of said planetary gear members of said second planetary gearset and said third planetary gearset to serve as a reaction member in both said forward drive ratio and said reverse drive ratio;

a fourth torque transmitting mechanism selectively operable to engage said second planetary gearset for rotation with said input shaft; and

a fifth torque transmitting mechanism for selectively braking rotation of said third planetary gearset.

11. The power transmission according to claim 10 wherein said third torque transmitting mechanism is chosen from the group consisting essentially of a multi-plate clutch mechanism and a band-type brake assembly.

12. 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 connected with the engine for rotation therewith;

an output shaft;

a first planetary gearset having a first member continuously drivingly connected with said input shaft, a second member and a third member;

a second planetary gearset having a first member drivingly interconnected with said output shaft, a second member and a third member;

a third planetary gearset having a first member drivingly interconnected with said output shaft;

a first torque transmitting mechanism selectively operable to engage said second member of said first planetary gearset with said third member of said second planetary gearset to provide a first forward launch ratio;

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

a third torque transmitting mechanism for selectively braking rotation of at least one of said second member of said second planetary gearset and said second member of said third planetary gearset to serve as a reaction member in both said first forward launch ratio and said reverse launch ratio.

13. The power transmission of claim 12 wherein said first member of said second planetary gearset and said first member of said third planetary gearset are formed as a single unitary member.

14. The power transmission of claim 12 wherein said third member of said first planetary gearset is fixedly coupled to a housing of said power transmission.

15. The power transmission of claim 14 wherein said second member of said second planetary gearset is fixedly coupled to said second member of said third planetary gearset.

16. The power transmission of claim 12 wherein said first torque transmitting mechanism is fully engaged prior to controlled engagement of said third torque transmitting mechanism to establish said first forward launch ratio between said input shaft and said output shaft.

17. The power transmission of claim 16 wherein said second torque transmitting mechanism is fully engaged prior to controlled engagement of said third torque transmitting mechanism to establish said reverse launch ratio between said input shaft and said output shaft.

18. The power transmission of claim 17 further including:

a fourth torque transmitting mechanism selectively operable to engage said second member of said second planetary gearset for rotation with said input shaft; and

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

19. 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 connectable with the engine for rotation therewith;

an output shaft;

a first planetary gearset having a first member operably coupled with said input shaft, a second member and a third member;

a second planetary gearset having a first member drivingly interconnected with said output shaft, a second member and a third member;

a third planetary gearset having a first member drivingly interconnected with said output shaft;

a first torque transmitting mechanism selectively operable to engage said second member of said first planetary gearset with said third member of said second planetary gearset to provide a first forward launch ratio;

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

a third torque transmitting mechanism for selectively braking rotation of at least one of said second member of said second planetary gearset and said second member of said third planetary gearset to serve as a reaction member in both said first forward launch ratio and said reverse launch ratio, wherein said first torque transmitting mechanism is fully engaged prior to controlled engagement of said third torque transmitting mechanism to establish said first forward launch ratio between said input shaft and said output shaft.

20. The power transmission of claim 19 wherein said second torque transmitting mechanism is fully engaged prior to controlled engagement of said third torque transmitting mechanism to establish said reverse launch ratio between said input shaft and said output shaft.

21. The power transmission of claim 20 further including:

a fourth torque transmitting mechanism selectively operable to engage said second member of said second planetary gearset for rotation with said input shaft; and

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