Multi-speed transmission with a countershaft gearing

• US 7,640,818 B2
• Filed: 02/23/2007
• Issued: 01/05/2010
• Est. Priority Date: 02/23/2007
• Status: Expired due to Fees

• 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., Sowul, Henryk, Burgman, Boris I., Solt, Michael B.
• Primary Examiner(s): Pang; Roger L
• Assistant Examiner(s): YOUNG, EDWIN
• Application Number:
  US11/678,188
• Publication Number:
  US 20080202268A1
• Time in Patent Office: 1,047 Days
• Field of Search: 743/25, 743/29, 743/30, 743/31, 743/40
• US Class Current: 74/330
• CPC Class Codes: F16H 2003/007 with two flow paths, one being directly connected to the input, the other being connected to the input though a clutch
• CPC Class Codes: F16H 2003/0938 with multiple gears on the input shaft directly meshing with respective gears 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 74/19228 Multiple concentric clutch shafts
• CPC Class Codes: Y10T 74/19233 Plurality of counter shafts
• CPC Class Codes: Y10T 74/19288 Double clutch and interposed transmission

Abstract

A transmission is provided having a dual clutch, to achieve torque flow through a countershaft gearing arrangement. The countershaft gearing arrangement includes a plurality of co-planar gear sets having gears that are selectively connectable to a plurality of countershafts. At least one transfer gear set transfers torque from the counter shafts to an output shaft. The output shaft is connected to a final drive unit that has a final drive unit output shaft that is transverse to an input member connected at one end to a torque converter and at the other end to the dual clutch.

Claims

1. A transmission comprising:

an input member;

first, second, third, fourth, and fifth co-planar gear sets each having a first gear member intermeshed with a second gear member, and wherein the third and fourth gear sets each include a third gear member intermeshed with the first gear member;

a first intermediate member continuously interconnected with a first plurality of the first gear members;

a second intermediate member concentric with the first intermediate member and continuously interconnected with a second plurality of the first gear members;

a countershaft selectively connectable with a first plurality of the second and third gear members;

an output member selectively connectable with a second plurality of the second and third gear members;

a torque transmitting assembly selectively engageable to interconnect the input member with at least one of the first and second intermediate members;

four synchronizer assemblies for selectively coupling the second and third gear members of the first, second, third, fourth, and fifth gear sets with one of the countershaft and the output member;

a first transfer gear set interconnected between the countershaft and the output member for transferring torque from the countershaft to the output shaft, and

wherein the torque transmitting assembly and four synchronizer assemblies are selectively engageable in combinations of at least two to establish at least seven forward speed ratios and at least one reverse speed ratio between the input member and the output member.

2. The transmission of claim 1 wherein the four synchronizer assemblies include a first synchronizer assembly for selectively coupling one of the second gear of the first gear set and the second gear of the third gear set with the countershaft.

3. The transmission of claim 2 wherein the four synchronizer assemblies include a second synchronizer assembly for selectively coupling one of the second gear of the fourth gear set and the second gear of the fifth gear set with the countershaft.

4. The transmission of claim 3 wherein the four synchronizer assemblies include a third synchronizer assembly for selectively coupling one of the second gear of the second gear set and the third gear of the third gear set with the output member.

5. The transmission of claim 4 wherein the fifth gear set includes an idler gear and a third gear, wherein the idler gear is intermeshed with the first gear of the fifth gear set and the third gear of the fifth gear set, and wherein the idler gear is rotatable about an idler axis.

6. The transmission of claim 5 wherein the four synchronizer assemblies include a fourth synchronizer assembly for selectively coupling one of the third gear of the fourth gear set and the third gear of the fifth gear set with the output member.

7. The transmission of claim 1 wherein the torque transmitting assembly is a dual clutch having a first hub connected to the first intermediate member and a second hub connected to the second intermediate member.

8. The transmission of claim 7 wherein the first hub is remote from the second hub, and wherein the output member is interconnected to an output shaft of a final drive unit, and wherein the output shaft of the final drive unit is perpendicular to the input member and is disposed between the first hub and the second hub.

9. The transmission of claim 7 wherein the torque transmitting assembly is located between a first plurality of the gear sets and a second plurality of the gear sets.

10. The transmission of claim 9 wherein the first plurality of gear sets includes the first, second, and third gear sets, and wherein the second plurality of gear sets includes the fourth and fifth gear sets.

11. The transmission of claim 1 further comprising a transfer gear shaft axially aligned with the input member and a second transfer gear, wherein the first transfer gear includes a first gear member interconnected to the transfer gear shaft and a second gear member intermeshed with the first gear member of the first transfer gear and interconnected to the countershaft, and wherein the second transfer gear includes a first gear member interconnected to the transfer gear shaft and a second gear member intermeshed with the first gear member of the second transfer gear and interconnected to the output member.

12. The transmission of claim 11 wherein the input member is rotatingly fixed to one of the first intermediate member and the second intermediate member and the torque transmitting assembly includes a clutch for selectively coupling the input member to the other of the first intermediate member and the second intermediate member.

13. The transmission of claim 12 further comprising a fifth synchronizer for selectively coupling the second gear of the first transfer gear to the countershaft.

14. The transmission of claim 12 further comprising a clutch for selectively coupling the second gear of the first transfer gear to the countershaft.

15. The transmission of claim 1 further comprising a transfer gear shaft axially offset from the input member, wherein the first transfer gear includes a first gear, a second gear, and a third gear, and wherein the first gear is interconnected with the transfer gear shaft and is intermeshed with the second gear and the third gear, the second gear is interconnected with the countershaft, and the third gear is interconnected with the output member.

16. The transmission of claim 1 further comprising a first wall, a second wall, and a third wall, wherein the second wall is located between the first and third walls.

17. The transmission of claim 16 wherein the first, second, third, fourth, and fifth gear sets are located between the first and second walls and the first transfer gear is located between the second and third walls.

18. The transmission of claim 17 further comprising a fourth wall, wherein the fourth and fifth gear sets are located between the first and fourth walls and the first, second, and third gear sets are located between the fourth and second walls.

19. The transmission of claim 1 wherein the first transfer gear includes a drive sprocket, a driven sprocket, and transfer member, wherein the drive sprocket is interconnected with the countershaft, the driven sprocket is interconnected with the output member, and the transfer member is engaged with both the drive sprocket and the driven sprocket for transferring torque from the drive sprocket to the driven sprocket.

20. The transmission of claim 1 further comprising a transfer gear shaft axially aligned with the input member and a second transfer gear, wherein the first transfer gear includes a first gear member interconnected to the transfer gear shaft and a second gear member intermeshed with the first gear member of the first transfer gear and interconnected to the countershaft, and wherein the second transfer gear includes a first gear member interconnected to the transfer gear shaft, a second gear member intermeshed with the first gear member of the second transfer gear and interconnected to the output member, and a transfer pinion intermeshed with the first gear of the second transfer gear that is selectively connectable to the countershaft.

21. The transmission of claim 20 wherein the four synchronizer assemblies include a first synchronizer assembly for selectively coupling the second gear of the second gear set to the countershaft.

22. The transmission of claim 21 wherein the four synchronizer assemblies include a second synchronizer assembly for selectively coupling one of the second gear of the first gear set and the second gear of the third gear set with the countershaft.

23. The transmission of claim 22 wherein the four synchronizer assemblies include a third synchronizer assembly for selectively coupling one of the second gear of the fourth gear set and the transfer pinion of the second transfer gear with the countershaft.

24. The transmission of claim 23 further comprising an idler gear set that includes a first gear, a second gear, and an idler gear, wherein the first gear is interconnected with the second intermediate member, the second gear is selectively connectable to the output member, and the idler gear is rotatable about an idler axis and is intermeshed with both the first gear and the second gear of the idler gear set.

25. The transmission of claim 24 wherein the four synchronizer assemblies include a fourth synchronizer assembly for selectively coupling one of the third gear of the third gear set and the second gear of the idler gear set with the output member.