Multi-speed transmission with countershaft gearing arrangement

• US 7,987,740 B2
• Filed: 09/03/2008
• Issued: 08/02/2011
• Est. Priority Date: 09/03/2008
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Ross, Craig S.
• Primary Examiner(s): Le; David D
• Assistant Examiner(s): Hlavka; David J
• Application Number:
  US12/203,469
• Publication Number:
  US 20100050797A1
• Time in Patent Office: 1,063 Days
• Field of Search: None
• 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 74/19233 Plurality of counter shafts

Abstract

A transmission includes an input member, an output member, a first and second interconnecting member, a plurality of countershafts, a reverse member, a plurality of co-planar gear sets, and a plurality of torque transmitting devices. The torque transmitting devices include 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:

an input member;

an output member;

a first interconnecting member;

a second interconnecting member;

a dual clutch assembly for selectively coupling the input member with the first interconnecting member and the second interconnecting member;

first, second, third, and fourth gear sets each having a first gear intermeshed with a second gear and a third gear, wherein the first and second gear sets are continuously interconnected with the first interconnecting member, the third and fourth gear sets are continuously interconnected with the second interconnecting member;

a fifth gear set having a first gear and a second gear;

a first countershaft continuously connected to the fifth gear set;

a second countershaft continuously connected to the fifth gear set;

a reverse shaft having a fourth gear intermeshed with at least one of the second, third and fourth gear sets; and

five synchronizer assemblies each for selectively coupling at least one of the first, second, third, and fourth gear sets with at least one of the first countershaft, the second countershaft, and the reverse shaft, and

wherein the five synchronizer assemblies and the dual clutch assembly are selectively engageable to establish a plurality of 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 first countershaft and the second countershaft are each located radially outward from and parallel to the input member.

3. The transmission of claim 1 wherein the output member is a final drive transfer gear in a differential.

4. The transmission of claim 1 wherein the reverse shaft is located radially outward from and parallel to the input member.

5. The transmission of claim 1 wherein the first countershaft is located at least partially above the reverse shaft and the second countershaft.

6. The transmission of claim 5 wherein the reverse shaft is located at least partially above the second countershaft.

7. The transmission of claim 1 wherein the first, second, third, fourth, and fifth gear sets are co-planar gear sets.

8. The transmission of claim 1 wherein the first gears of the first and second gear sets are continuously interconnected to the first interconnecting member and the first gears of the third and fourth gear sets are continuously connected to the second interconnecting member.

9. The transmission of claim 8 wherein a first of the five synchronizer assemblies selectively connects the second gear of the first gear set to the reverse shaft.

10. The transmission of claim 9 wherein a second of the five synchronizer assemblies selectively connects the second gear of the second gear set to the first countershaft.

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

12. The transmission of claim 11 wherein a fourth of the five synchronizer assemblies selectively connects one of the third gear of the first gear set and the third gear of the second gear set to the second countershaft.

13. The transmission of claim 12 wherein a fifth of the five synchronizer assemblies selectively connects one of the third gear of the third gear set and the third gear of the fourth gear set to the second countershaft.

14. The transmission of claim 1 wherein the first gear of the fifth gear set is continuously interconnected to the first countershaft and is intermeshed with the output member and the second gear of the fifth gear set is continuously interconnected to the second countershaft and is intermeshed with the output member.

15. A transmission comprising:

an input member;

an output member;

a first interconnecting member;

a second interconnecting member;

a dual clutch assembly for selectively coupling the input member with the first interconnecting member and the second interconnecting member;

first, second, third, and fourth gear sets each having a first gear intermeshed with a second gear and a third gear, wherein the first and second gear sets are continuously interconnected with the first interconnecting member, the third and fourth gear sets are continuously interconnected with the second interconnecting member;

a fifth gear set having a first gear and a second gear;

a first countershaft continuously connected to the fifth gear set;

a second countershaft continuously connected to the fifth gear set;

a reverse shaft having a fourth gear intermeshed with at least one of the second, third and fourth gear sets;

a first synchronizer assembly for selectively connecting the second gear of the first gear set to the reverse shaft;

a second synchronizer assembly for selectively connecting the second gear of the second gear set to the first countershaft;

a third synchronizer assembly for selectively connecting one of the second gear of the third gear set and second gear of the fourth gear set to the first countershaft;

a fourth synchronizer assembly for selectively connecting one of the third gear of the first gear set and the third gear of the second gear set to the second countershaft; and

a fifth synchronizer assembly for selectively connecting one of the third gear of the third gear set and the third gear of the fourth gear set to the second countershaft, and

wherein the five synchronizer assemblies and the dual clutch assembly are selectively engageable to establish a plurality of forward speed ratios and at least one reverse speed ratio between the input member and the output member.

16. The transmission of claim 15 wherein the first countershaft and the second countershaft are each located radially outward from and parallel to the input member.

17. The transmission of claim 15 wherein the output member is a final drive transfer gear in a differential.

18. The transmission of claim 15 wherein the reverse shaft is located radially outward from and parallel to the input member.

19. The transmission of claim 15 wherein the first countershaft is located at least partially above the reverse shaft and the second countershaft.

20. The transmission of claim 15 wherein the reverse shaft is located at least partially above the second countershaft.

21. The transmission of claim 15 wherein the first gears of the first and second gear sets are continuously interconnected to the first interconnecting member and the first gears of the third and fourth gear sets are continuously interconnected to the second interconnecting member.

22. The transmission of claim 15 wherein the first gear of the fifth gear set is continuously interconnected to the first countershaft and is intermeshed with the output member and the second gear of the fifth gear set is continuously interconnected to the second countershaft and is intermeshed with the output member.

23. A transmission comprising:

an input member;

an output member;

a first interconnecting member;

a second interconnecting member;

a dual clutch assembly for selectively coupling the input member with the first interconnecting member and the second interconnecting member;

first, second, third, and fourth gear sets each having a first gear intermeshed with a second gear and a third gear, wherein the first and second gear sets are continuously interconnected with the first interconnecting member, the third and fourth gear sets are continuously interconnected with the second interconnecting member;

a fifth gear set having a first gear and a second gear;

a first countershaft continuously connected to the fifth gear set and located radially outward from and parallel to the first and second interconnecting members;

a second countershaft continuously connected to the fifth gear set and located radially outward from and parallel to the input member;

a reverse shaft having a fourth gear intermeshed with at least one of the second, third and fourth gear sets and located radially outward from and parallel to the input member and located at least partially below the first countershaft and at least partially above the second countershaft;

a first synchronizer assembly for selectively connecting the second gear of the first gear set to the reverse shaft;

a second synchronizer assembly for selectively connecting the second gear of the second gear set to the first countershaft;

a third synchronizer assembly for selectively connecting one of the second gear of the third gear set and second gear of the fourth gear set to the first countershaft;

a fourth synchronizer assembly for selectively connecting one of the third gear of the first gear set and the third gear of the second gear set to the second countershaft; and

a fifth synchronizer assembly for selectively connecting one of the third gear of the third gear set and the third gear of the fourth gear set to the second countershaft,

wherein the five synchronizer assemblies and the dual clutch assembly are selectively engageable to establish at least seven forward speed ratios and at least one reverse speed ratio between the input member and the output member.