Transmission with long ring planetary gearset

• US 7,029,417 B2
• Filed: 06/21/2004
• Issued: 04/18/2006
• Est. Priority Date: 11/15/2001
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Borgerson, James B., Maguire, Joel M., Kienzle, Kent H.
• Primary Examiner(s): Bonck, Rodney H.
• Assistant Examiner(s): Le, David D.
• Application Number:
  US10/872,726
• Publication Number:
  US 20040235608A1
• Time in Patent Office: 666 Days
• Field of Search: 475/275, 475/280, 475/284, 475/323, 475/325, 475/340, 475/319, 475/313, 475/338
• US Class Current: 475/284
• 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 connectable with an engine and a planetary gear unit. The gear unit includes two planes of gears drivingly coupled to one another. A single carrier rotatably supports pinion gears from each plane of gears. A long ring engages the pinion gears from each plane of gears.

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 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 second member and a third member, wherein said first member of said second planetary gearset and said first member of said third planetary gearset are unitarily formed as a ring gear directly engaging a pinion gear of said second planetary gearset and a pinion gear of said third planetary gearset, said pinion gears being rotatable relative to one another;

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 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 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 one of said first forward ratio and said reverse ratio.

2. The power transmission of claim 1 wherein said second member of said second planetary gearset and said second member of said third planetary gearset are unitarily formed as a carrier, said carrier having a post rotatably supporting said pinion gear of said second planetary gearset and said pinion gear of said third planetary gearset.

3. The power transmission of claim 2 wherein said carrier has a center web coupled to said post, said center web being positioned between said pinion gears of said second and third planetary gearsets.

4. The power transmission of claim 3 wherein said unitary ring gear includes a first portion and a second portion fixed to one another, said first portion engaging said pinion gear of said second planetary gearset, said second portion engaging said pinion gear of said third planetary gearset.

5. The power transmission of claim 4 wherein said first portion includes helical teeth extending in a first handed direction, said second portion including helical teeth extending in a handed direction opposite said first handed direction.

6. The power transmission of claim 5 wherein said third planetary gearset includes a thrust bearing positioned between said pinion of said second planetary gearset and said center web.

7. 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 connectable with the engine for rotation therewith;

an output shaft;

a gear reduction unit having a first plane of gears drivingly connected to a second plane of gears, said first plane of gears having a ring gear directly engaging said output shaft, said ring gear being drivingly interconnected with a first sun gear, a first pinion gear and a carrier, said second plane of gears including a second sun gear, a second pinion gear individually rotatable relative to said first pinion gear, said carrier and said ring gear, said ring gear directly engaging said first and second pinion gears;

a third plane of gears drivingly connected to said gear reduction unit; and

a torque transmitting mechanism selectively operable to engage one of said first and second sun gears with said input shaft to provide a drive ratio.

8. The power transmission of claim 7 wherein said third plane of gears is selectively drivingly connected to said input shaft.

9. The power transmission of claim 7 wherein said ring gear includes a first portion including helical teeth extending in a first handed direction and a second portion including helical teeth extending in a handed direction opposite said first handed direction.

10. The power transmission of claim 9 wherein said gear reduction unit includes a thrust bearing positioned between said first pinion and said center web.

11. The power transmission of claim 7 wherein said carrier includes a post rotatably supporting said first pinion gear and said second pinion gear.

12. The power transmission of claim 11 wherein said carrier includes a center web radially extending from said post, said center web being positioned between said first and second pinion gears.

13. The power transmission of claim 11 wherein said carrier includes a front flange coupled to a first end of said post and a rear flange coupled to a second end of said post, said front flange radially extending from said post and being coupled to a second torque transmitting mechanism.

14. The power transmission of claim 13 wherein said second torque transmitting mechanism is a brake selectively coupling said carrier to a housing of said power transmission.

15. The power transmission of claim 14 wherein said first pinion, said center web and said second pinion are axially positioned between said front flange and said rear flange of said carrier.

16. 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 connectable with the engine for rotation therewith;

an output shaft;

first and secondary planetary gearsets having a common carrier and a common ring gear, said first planetary gearset including a first pinion gear rotatably supported by said carrier, said second planetary gearset including a second pinion gear rotatably supported by said carrier, said first pinion gear being axially spaced apart from said second pinion gear, said ring gear directly engaging said output shaft and said first and second pinion gears;

a speed reduction unit drivingly connected to one of said first and second planetary gearsets; and

a first torque transmitting mechanism selectively operable to engage a member of said first planetary gearset with said input shaft to provide a drive ratio.

17. The power transmission of claim 16 wherein said carrier includes a center web positioned between said first and second pinion gears.

18. The power transmission of claim 17 wherein said carrier includes a post rotatably supporting said first pinion gear and said second pinion gear on a common axis, said post extending through said center web.

19. The power transmission of claim 18 wherein said ring gear includes a first portion and a second portion fixed to one another, said first portion engaging said first pinion gear and said second portion engaging said second pinion gear.

20. The power transmission of claim 19 wherein said first portion includes helical teeth extending in a first handed direction, said second portion including helical teeth extending in a handed direction opposite said first handed direction.

21. 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 connectable with the engine for rotation therewith;

an output shaft;

a gear reduction unit having a first plane of gears drivingly connected to a second plane of gears, said first plane of gears having a ring gear drivingly interconnected with said output shaft, a first sun gear, a first pinion gear and a carrier, said second plane of gears including a second sun gear, a second pinion gear individually rotatable relative to said first pinion gear, said carrier and said ring gear, said ring gear directly engaging said first and second pinion gears;

a third plane of gears drivingly connected to said gear reduction unit; and

a torque transmitting mechanism selectively operable to engage one of said first and second sun gears with said input shaft to provide a drive ratio, wherein said ring gear includes a first portion including helical teeth extending in a first handed direction and a second portion including helical teeth extending in a handed direction opposite said first handed direction.

22. The power transmission of claim 21 wherein said gear reduction unit includes a thrust bearing positioned between said first pinion and said center web.

23. 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 connectable with the engine for rotation therewith;

an output shaft;

a gear reduction unit having a first plane of gears drivingly connected to a second plane of gears, said first plane of gears having a ring gear drivingly interconnected with said output shaft, a first sun gear, a first pinion gear and a carrier, said second plane of gears including a second sun gear, a second pinion gear individually rotatable relative to said first pinion gear, said carrier and said ring gear, said ring gear directly engaging said first and second pinion gears;

a third plane of gears drivingly connected to said gear reduction unit; and

a torque transmitting mechanism selectively operable to engage one of said first and second sun gears with said input shaft to provide a drive ratio, wherein said carrier includes a post rotatably supporting said first pinion gear and said second pinion gear, a front flange coupled to a first end of said post and a rear flange coupled to a second end of said post, said front flange radially extending from said post and being coupled to a second torque transmitting mechanism.

24. The power transmission of claim 23 wherein said second torque transmitting mechanism is a brake selectively coupling said carrier to a housing of said power transmission.

25. The power transmission of claim 24 wherein said first pinion, said center web and said second pinion are axially positioned between said front flange and said rear flange of said carrier.

26. 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 connectable with the engine for rotation therewith;

an output shaft;

first and secondary planetary gearsets having a common carrier and a common ring gear, said first planetary gearset including a first pinion gear rotatably supported by said carrier, said second planetary gearset including a second pinion gear rotatably supported by said carrier, said first pinion gear being axially spaced apart from said second pinion gear, said ring gear being drivingly interconnected with said output shaft, said ring gear directly engaging said first and second pinion gears;

a speed reduction unit drivingly connected to one of said first and second planetary gearsets; and

a first torque transmitting mechanism selectively operable to engage a member of said first planetary gearset with said input shaft to provide a drive ratio, wherein said carrier includes a center web positioned between said first and second pinion gears, wherein said carrier includes a post rotatably supporting said first pinion gear and said second pinion gear on a common axis, said post extending through said center web, wherein said ring gear includes a first portion and a second portion fixed to one another, said first portion engaging said first pinion gear and said second portion engaging said second pinion gear, and further wherein said first portion includes helical teeth extending in a first handed direction, said second portion including helical teeth extending in a handed direction opposite said first handed direction.