IP Library › Granted Patent US 8,443,686

Granted Patent B2

US 8,443,686 · App. 12/764,612 · Granted May 21, 2013

Seven speed dual clutch transmission

Inventors: Tejinder Singh (Commerce Township, MI); Patrick S. Portell (Clarkston, MI)

Assignee: GM Global Technology Operations LLC

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Quick Facts

Patent No.: US 8,443,686
App. No.: 12/764,612
Granted: May 21, 2013
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

A transmission connectable to an input member and having an output transfer gear, first and second transmission input shaft members, first and second countershaft members, an idler shaft, a plurality of co-planar gear sets, and a plurality of torque transmitting devices. 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 transmission input members and the output member.

Claims (42)

1. A transmission comprising:

a transmission housing;

a dual clutch assembly having a clutch housing connectable to an engine output member, wherein the clutch housing is rotationally supported within the transmission housing;

a first, second, third, fourth and fifth gear set, wherein the first gear set includes a first gear in mesh with a 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, wherein the second gear of the first gear set is a stepped pinion gear having a first and a second gear teeth portions, and wherein the first gear teeth portion is larger than the second gear teeth portion and meshes with the first gear of the first gear set and the second gear teeth portion meshes with a reverse gear;

a second transmission input member rotatably supported in the transmission housing and, wherein each of the first gears of the first and second gear sets are rotatably fixed for common rotation with the second transmission input member and wherein 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 and spaced apart from and parallel with the first and second transmission input members, wherein the reverse gear, 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 rotatably supported within the transmission housing and spaced apart from and parallel with the first and second transmission input members, wherein the second gear of the first gear set, the second gear of the second gear set, the second gear of the third gear set and the second gear of the fifth gear set are each selectively connectable for common rotation with the second countershaft; and

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 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.

3. The transmission of claim 2 wherein a second of the four synchronizer assemblies selectively connects at least one of the reverse gear and third gear of the second gear set to the first countershaft.

4. The transmission of claim 3 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.

5. The transmission of claim 4 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.

6. 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.

7. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the dual clutch housing to the second transmission input 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.

8. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the dual clutch housing to the second transmission input 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.

9. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the dual clutch housing to the second transmission input member and wherein the four synchronizer assemblies includes a second synchronizer assembly for selectively connecting the reverse gear to the first countershaft to establish a reverse gear ratio.

10. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the second clutch is configured to selectively connect the dual clutch housing to the second transmission input 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.

11. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the dual clutch housing to the first transmission input 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.

12. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the dual clutch housing to the first transmission input 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 third gear ratio.

13. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the dual clutch housing to the first transmission input 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.

14. The transmission of claim 6 wherein the dual clutch assembly includes a first clutch and a second clutch, wherein the first clutch is configured to selectively connect the dual clutch housing to the first transmission input 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 first gear ratio.

15. 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 a transmission output member.

16. The transmission of claim 15 wherein the transmission output member is a gear that meshes with the each of the first and second countershaft transfer gears.

17. The transmission of claim 15 further comprising a park gear fixed to a first end of a park gear shaft and a park transfer gear fixed to a second end of the park gear shaft and wherein the park transfer gear meshes with the transmission output member and wherein the park gear is configured to prevent rotation of the transmission output member when the park gear is engaged.

18. The transmission of claim 15 further comprising a park gear fixed to the first countershaft, wherein the park gear is configured to prevent rotation of the first countershaft transfer gear and the transmission output member when the park gear is engaged.

19. A transmission comprising:

a transmission housing;

a dual clutch assembly having a clutch housing connectable to an engine output member, wherein the clutch housing is rotationally supported within the transmission housing and wherein the dual clutch assembly includes a first clutch and a second clutch;

a first transmission input member rotatably supported in the transmission housing, and wherein each of the first gears of the third, fourth and fifth gear set are rotatably fixed for common rotation with the first transmission input member and wherein the first clutch of the dual clutch assembly is configured to selectively connect the dual clutch housing to the first transmission input member;

a first synchronizer assembly 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;

a second synchronizer assembly selectively connects at least one of the reverse gear and third gear of the second gear set to the first countershaft;

a third synchronizer assembly 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;

a fourth synchronizer assembly 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;

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 a transmission output member; and

a park gear fixed to a first end of a park gear shaft and a park transfer gear fixed to a second end of the park gear shaft and wherein the park transfer gear meshes with the transmission output member and wherein the park gear is configured to prevent rotation of the transmission output member when the park gear is engaged, 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 synchronizer assemblies establishes at least one of seven forward speed ratios between the at least one of the first and the second transmission input members and the transmission output member.

Assignments (4)

RELEASE OF SECURITY INTEREST Recorded Nov 7, 2014

From: WILMINGTON TRUST COMPANY

To: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Reel/Frame 034287/0001 →

CHANGE OF NAME Recorded Feb 10, 2011

From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.

To: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Reel/Frame 025781/0333 →

SECURITY AGREEMENT Recorded Nov 8, 2010

From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.

To: WILMINGTON TRUST COMPANY