Seven speed dual clutch transmission having improved packaging

• US 8,607,655 B2
• Filed: 05/24/2013
• Issued: 12/17/2013
• Est. Priority Date: 08/06/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Singh, Tejinder, Portell, Patrick S.
• Primary Examiner(s): Chambers, Troy
• Assistant Examiner(s): GONZALEZ, MICHAEL P
• Application Number:
  US13/902,078
• Publication Number:
  US 20130269460A1
• Time in Patent Office: 207 Days
• Field of Search: 743/30, 743/31, 743/33, 743/40
• US Class Current: 74/331
• CPC Class Codes: F16H 2003/0931 each countershaft having an output gear meshing with a single common gear on the output shaft
• CPC Class Codes: F16H 2200/0056 the gear ratios comprising seven forward speeds
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/093 with two or more countershafts
• CPC Class Codes: Y10T 74/19051 Single driven plural drives
• CPC Class Codes: Y10T 74/1907 Parallel and aligned
• CPC Class Codes: Y10T 74/19228 Multiple concentric clutch shafts
• CPC Class Codes: Y10T 74/19233 Plurality of counter shafts

Abstract

A transmission connected to an engine input member and having an output transfer gear, first and second transmission input shaft members, first and second countershaft members, a plurality of co-planar gear sets, and a plurality of torque transmitting devices. The first and second transmission input shaft members are rotatably supported in the transmission housing by a combination of ball and needle bearings. The first and second countershaft members are rotatably supported in the transmission housing by plurality of thrust bearings. The torque transmitting devices include a plurality of synchronizer assemblies and a dual clutch assembly. The transmission is operable to provide at least one reverse speed ratio and a plurality of forward speed ratios between the input member and the output member.

Claims

1. A transmission comprising:

a transmission housing;

a dual clutch assembly having a clutch housing connectable to a flywheel of an engine and a first and second output;

a first, second, third, fourth, and fifth gear set, wherein the first gear set includes a first gear in mesh with a second gear and a third gear in mesh with the second gear, the second gear set includes a first gear in mesh with a second gear and a third gear, the third gear set includes a first gear in mesh with a second gear and a third gear, the fourth gear set includes a first gear in mesh with a second gear, the fifth gear set includes a first gear in mesh with a second gear;

a first transmission input member selectively coupled for common rotation to the flywheel via the dual clutch assembly, and wherein each of the first gear of the third, fourth and fifth gear sets are rotatably fixed for common rotation on the first transmission input member;

a second transmission input member selectively coupled for common rotation to the flywheel via the dual clutch assembly, and wherein each of the first gear of the first and second gear sets are rotatably fixed for common rotation with the second transmission input member;

a first countershaft disposed parallel to the first and second transmission input members, wherein the third gear of the first gear set, the third gear of the second gear set, the third gear of the third gear set and the second gear of the fourth gear set are each selectively connectable for common rotation with the first countershaft;

a second countershaft disposed parallel to the first and second transmission input members, and wherein the second gear of the first gear set, the second gear of the second gear, and the second gear of the fifth gear set are each selectively connectable for common rotation with the second countershaft;

four synchronizer assemblies for selectively coupling at least one of the gears of the first, second, third, fourth and fifth gear sets with at least one of the first countershaft and the second countershaft, and

wherein the selective engagement of dual clutch assembly interconnects the dual clutch housing with at least one of the first and the second transmission input members and the selective engagement of at least one of the four synchronizer assemblies establishes at least one of seven forward speed ratios.

2. The transmission of claim 1 wherein the clutch housing is rotationally supported within the transmission housing by a first ball bearing assembly.

3. The transmission of claim 2 wherein the first transmission input member has a first end portion and a second end portion, the first end portion is rotatably supported in the transmission housing by a second ball bearing assembly, and the second end portion is rotatably supported in the transmission housing by a first needle bearing assembly.

4. The transmission of claim 3 wherein the second transmission input member has a first end portion and a second end portion, the first end portion is rotatably supported in the transmission housing by a second needle bearing assembly, the second end portion is rotatably supported in the transmission housing by a third ball bearing assembly, and the third ball bearing assembly is axially aligned and concentric with the first needle bearing assembly.

5. The transmission of claim 4 wherein the first countershaft is rotatably supported within the transmission housing by a first and a second set of thrust bearings.

6. The transmission of claim 5 wherein the second countershaft is rotatably supported within the transmission housing by a third and a fourth set of thrust bearings.

7. The transmission of claim 6 further comprising a tone wheel fixedly connected to the second countershaft and axially aligned with the third ball bearings assembly.

8. The transmission of claim 1 wherein a first of the four synchronizer assemblies selectively connects at least one of the second gear of the first gear set and the second gear of the second gear set to the second countershaft shaft.

9. The transmission of claim 8 wherein a second of the four synchronizer assemblies selectively connects at least one of the third gear of the first gear set and third gear of the second gear set to the first countershaft shaft.

10. The transmission of claim 9 wherein a third of the four synchronizer assemblies selectively connects at least one of the second gear of the third gear set and the second gear of the fifth gear set to the second countershaft shaft.

11. The transmission of claim 10 wherein a fourth of the four synchronizer assemblies selectively connects at least one of the third gear of the third gear set and the second gear of the fourth gear set to the first countershaft shaft.

12. The transmission of claim 1 wherein the first gear set is adjacent the dual clutch assembly, the second gear set is adjacent the first gear set, the third gear set is adjacent the second gear set, the fourth gear set is adjacent the third gear set, and the fifth gear set is adjacent the fourth gear set.

13. The transmission of claim 12 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the input member to the second interconnecting member and wherein the four synchronizer assemblies includes a first synchronizer assembly for selectively connecting the second gear of the first gear set to the second countershaft to establish a second gear ratio.

14. The transmission of claim 13 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the input member to the second interconnecting member and wherein the four synchronizer assemblies includes a first synchronizer assembly for selectively connecting the second gear of the second gear set to the second countershaft to establish a sixth gear ratio.

15. The transmission of claim 14 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the input member to the second interconnecting member and wherein the four synchronizer assemblies includes a second synchronizer assembly for selectively connecting the third gear of the first gear set to the first countershaft to establish a reverse gear ratio.

16. The transmission of claim 15 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the input member to the second interconnecting member and wherein the four synchronizer assemblies includes a second synchronizer assembly for selectively connecting the third gear of the second gear set to the first countershaft to establish a fourth gear ratio.

17. The transmission of claim 16 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the input member to the first interconnecting member and wherein the four synchronizer assemblies includes a third synchronizer assembly for selectively connecting the second gear of the third gear set to the second countershaft to establish a seventh gear ratio.

18. The transmission of claim 17 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the input member to the first interconnecting member and wherein the four synchronizer assemblies includes a third synchronizer assembly for selectively connecting the second gear of the fifth gear set to the second countershaft to establish a first gear ratio.

19. The transmission of claim 18 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the input member to the first interconnecting member and wherein the four synchronizer assemblies includes a fourth synchronizer assembly for selectively connecting the third gear of the third gear set to the first countershaft to establish a fifth gear ratio.

20. The transmission of claim 19 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the input member to the first interconnecting member and wherein the four synchronizer assemblies includes a fourth synchronizer assembly for selectively connecting the second gear of the fourth gear set to the first countershaft to establish a third gear ratio.

21. The transmission of claim 1 further comprising a first countershaft transfer gear fixed to the first countershaft for common rotation with the first countershaft and a second countershaft transfer gear fixed to the second countershaft for common rotation with the second countershaft and wherein the first and second countershaft transfer gears transfer torque from at least one of the first and second countershafts to the output member.

22. The transmission of claim 21 wherein the output member is a gear that meshes with the each of the first and second countershaft transfer gears.

23. A transmission comprising:

a transmission housing;

a dual clutch assembly having a clutch housing connectable to a flywheel of an engine, wherein the clutch housing is rotationally supported within the transmission housing by a first ball bearing assembly;

a first, second, third, fourth, and fifth gear sets each having a plurality of co-planar gears;

a first transmission input member having a first end portion and a second end portion, and wherein the first end portion is rotatably supported in the transmission housing by a second ball bearing assembly, the second end portion is rotatably supported in the transmission housing by a first needle bearing assembly, the first needle bearing assembly is disposed adjacent a second end wall of the transmission housing proximate to the dual clutch assembly, one of the plurality of co-planar gears of each of the third, fourth and fifth gear set are rotatably fixed for common rotation with the first transmission input member, and the second ball bearing assembly is adjacent a first end wall of the transmission housing;

a second transmission input member having a first end portion and a second end portion, and wherein the first end portion is rotatably supported in the transmission housing by a second needle bearing assembly, the second end portion is rotatably supported in the transmission housing by a third ball bearing assembly, the second needle bearing assembly is disposed between the second ball bearing assembly and the third ball bearing assembly, the third ball bearing assembly is axially aligned and concentric with the first needle bearing assembly, one of the plurality of co-planar gears of each of the first and second gear sets are rotatably fixed for common rotation with the second transmission input member, and the second transmission input member is concentric with the first transmission input member and at least partially surrounds the first transmission input member;

a first countershaft rotatably supported within the transmission housing by a first and second set of thrust bearings and spaced apart from and parallel with the first and second transmission input members, and wherein another of the co-planar gears of the first gear set, second gear set, the third gear set, and the fourth gear set are each selectively connectable for common rotation with the first countershaft;

a second countershaft rotatably supported within the transmission housing by a third and fourth set of thrust bearings and spaced apart from and parallel with the first and second transmission input members, and wherein yet another of the co-planar gears of the first gear set, the second gear set, and the fifth gear set are each selectively connectable for common rotation with the second countershaft;

four synchronizer assemblies for selectively coupling at least one of the plurality of co-planar gears of the first, second, third, fourth and fifth gear sets with at least one of the first countershaft and the second countershaft, and

wherein the selective engagement of dual clutch assembly interconnects the dual clutch housing with at least one of the first and the second transmission input members and the selective engagement of at least one of the four synchronizer assemblies establishes at least one of seven forward speed ratios.

24. The transmission of claim 23 wherein the first gear set includes a first gear in mesh with a first portion of second gear and a third gear in mesh with a second portion of the second gear.

25. The transmission of claim 24 wherein the second gear set includes a first gear in mesh with a second gear and a third gear.

26. The transmission of claim 25 wherein the third gear set includes a first gear in mesh with a second gear and a third gear.

27. The transmission of claim 26 wherein the fourth gear set includes a first gear in mesh with a second gear.

28. The transmission of claim 27 wherein the fifth gear set includes a first gear in mesh with a second gear.

29. The transmission of claim 23 wherein the second ball bearing assembly is disposed adjacent a first end wall of the transmission housing.

30. The transmission of claim 29 wherein the first needle bearing assembly is disposed adjacent second end wall of the transmission housing proximate to the dual clutch assembly.

31. The transmission of claim 30 wherein a second needle bearing assembly is disposed between the second ball bearing assembly that is disposed adjacent the first end wall of the transmission housing and the third ball bearing assembly that is axially aligned and concentric with the first needle bearing assembly.

32. The transmission of claim 31 wherein the first set of thrust bearings is disposed at a first end of the first countershaft and the second set of thrust bearings is disposed at a second end of the first countershaft.

33. The transmission of claim 32 wherein the third set of thrust bearings is disposed at a first end of the second countershaft and the fourth set of thrust bearings is disposed at a second end of the second countershaft.

34. The transmission of claim 23 further comprising a tone wheel fixedly connected to the second countershaft and axially aligned with the third ball bearings assembly.