Seven speed dual clutch transmission

• US 8,789,434 B2
• Filed: 05/02/2013
• Issued: 07/29/2014
• Est. Priority Date: 05/12/2009
• 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): Ho, Ha D
• Application Number:
  US13/875,528
• Publication Number:
  US 20130239715A1
• Time in Patent Office: 453 Days
• Field of Search: 743/30, 743/31, 743/33, 743/40
• US Class Current: 74/330
• CPC Class Codes: F16D 2021/0615 the central input plate is supported by bearings in-between the two clutches
• CPC Class Codes: F16D 21/06 at least two driving shafts or two driven shafts being concentric
• 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 3/08 exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts
• CPC Class Codes: Y10T 74/19228 Multiple concentric clutch shafts
• CPC Class Codes: Y10T 74/19233 Plurality of counter shafts

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

1. A powertrain comprising:

an engine output member;

a transmission housing;

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

a first transmission input member rotatably supported in the transmission housing,

a second transmission input member rotatably supported in the transmission housing 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;

a second countershaft rotatably supported within the transmission housing and spaced apart from and parallel with the first and second transmission input members;

a reverse gear selectively connectable for common rotation to the first countershaft;

a first co-planar gear set having a first gear and a second gear, wherein the first gear is directly connected for common rotation with the second transmission input member and the second gear is selectively connectable for common rotation to the second countershaft, wherein the second gear includes a first gear teeth portion and a second gear teeth portion and a diameter of the first gear teeth portion is larger than a diameter of the second gear teeth portion, and wherein the first gear teeth portion meshes with the first gear of the first gear set and the second gear teeth portion meshes with the reverse gear;

a plurality of co-planar gear sets interconnected between the first and second transmission input shafts and the first and second countershafts; and

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

wherein the selective engagement of the 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 powertrain of claim 1 wherein the plurality of co-planar gear sets includes a second, third, fourth and fifth co-planar gear set, wherein 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, and the fifth gear set includes a first gear in mesh with a second gear.

3. The powertrain of claim 2 wherein each of the first gears of the third, fourth and fifth gear set are directly rotatably fixed for common rotation to the first transmission input member.

4. The powertrain of claim 3 wherein each of the first gears of the first and second gear sets are directly rotatably fixed for common rotation to the second transmission input member.

5. The powertrain of claim 4 wherein 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 by two of the our synchronizer assemblies.

6. The powertrain of claim 5 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 by another two of the four synchronizer assemblies.

7. The powertrain of claim 6 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.

8. The powertrain of claim 7 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.

9. The powertrain of claim 8 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.

10. The powertrain of claim 9 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.

11. The powertrain of claim 6 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.

12. The powertrain 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.

13. The powertrain of claim 12 wherein the transmission output member is a gear that meshes with the each of the first and second countershaft transfer gears.

14. The powertrain of claim 12 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.

15. The powertrain of claim 12 further comprising a park gear fixed to a 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.

16. 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, 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 meshes with the first gear of the first gear set and the second gear teeth portion meshes with a reverse gear;

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 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 and wherein the second clutch of the dual clutch assembly is configured to selectively connect the dual clutch housing to the second 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;

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

wherein the selective engagement of the 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.

17. 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, 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 that meshes with the first gear of the first gear set and with a reverse gear;

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 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 and wherein the second clutch of the dual clutch assembly is configured to selectively connect the dual clutch housing to the second 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;

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; and

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

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.