Dual-clutch transmission with multiple first gears

Patent metadata

Field	Value
Publication number	US-9897165-B2
Application number	US-201514941488-A
Country	US
Kind code	B2
Filing date	Nov 13, 2015
Priority date	Nov 21, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A dual-clutch transmission assembly is disclosed that splits the torque generated by an engine between first and second layshafts. A first input hub is connected to the first layshaft by a first clutch and a second input hub is connected to the second layshaft by a second clutch. A first gearset is carried on the first layshaft and a second gearset is carried on the second layshaft. The first gearset includes a primary first gear and the second gearset includes a duplicate first gear. The first and second layshafts receive torque from the transmission input shaft in response to contemporaneous engagement of the primary first gear, the duplicate first gear, and the first and second clutches, which can be used during vehicle launch to split the torque applied to the first and second clutches.

First claim

What is claimed is:

1. A dual-clutch transmission assembly that splits torque generated by an engine of a vehicle, the dual-clutch transmission assembly comprising:
a transmission input shaft that receives torque from the engine of the vehicle;
a transmission output shaft that supplies torque to drivetrain components of the vehicle;
a first layshaft;
a first input hub that is disposed adjacent said first layshaft and that is rotatably coupled with said transmission input shaft;
a second layshaft spaced from said first layshaft;
a second input hub that is disposed adjacent said second layshaft and that is rotatably coupled with said transmission input shaft;
a first clutch disposed between and interconnecting said first input hub and said first layshaft, said first clutch selectively coupling rotation of said first input hub with said first layshaft;
a second clutch disposed between and interconnecting said second input hub and said second layshaft, said second clutch selectively coupling rotation of said second input hub with said second layshaft;
a first gearset rotatably coupled to and carried on said first layshaft that transfers torque between said first layshaft and said transmission output shaft;
a second gearset rotatably coupled to and carried on said second layshaft that transfers torque between said second layshaft and said transmission output shaft;
said first gearset including a primary first gear having a primary first gear diameter;
said second gearset including a duplicate first gear having a duplicate first gear diameter that is equal to said primary first gear diameter; and
each of said first and second layshafts receiving torque from said transmission input shaft in response to contemporaneous engagement of said primary first gear, said duplicate first gear, said first clutch, and said second clutch to split the torque applied to said first and second clutches, wherein said first gearset further includes a plurality of odd numbered gears and said second gearset further includes a plurality of even numbered gears.

2. The dual-clutch transmission assembly as set forth in claim 1 wherein said primary first gear is disposed along said first layshaft between said first clutch and said plurality of odd numbered gears.

3. The dual-clutch transmission assembly as set forth in claim 2 wherein said duplicate first gear is disposed along said second layshaft adjacent said plurality of even numbered gears such that said plurality of even numbered gears are disposed between said second clutch and said duplicate first gear.

4. The dual-clutch transmission assembly as set forth in claim 1 wherein said plurality of odd numbered gears of said first gearset have gear diameters that increase with each higher numbered gear and said plurality of even numbered gears of said second gearset have gear diameters that increase with each higher numbered gear.

5. The dual-clutch transmission assembly as set forth in claim 1 further comprising:
a transmission input gear rotatably coupled to and carried on said transmission input shaft.

6. The dual-clutch transmission assembly as set forth in claim 5 further comprising:
a first layshaft input gear rotatably coupled to and carried on said first input hub that is arranged in meshing engagement with said transmission input gear; and
a second layshaft input gear rotatably coupled to and carried on said second input hub that is arranged in meshing engagement with said transmission input gear opposite said first layshaft input gear.

7. The dual-clutch transmission assembly as set forth in claim 1 wherein said first and second layshafts are parallel to one another and are transversely spaced.

8. The dual-clutch transmission assembly as set forth in claim 1 further comprising:
a single intermediate shaft extending parallel to and transversely spaced from said first and second layshafts.

9. The dual-clutch transmission assembly as set forth in claim 8 wherein said single intermediate shaft is positioned between said first layshaft and said second layshaft.

10. The dual-clutch transmission assembly as set forth in claim 8 further comprising:
a third gearset rotatably coupled to and carried on said single intermediate shaft that is arranged in meshing engagement with said first gearset; and
a fourth gearset rotatably coupled to and carried on said single intermediate shaft that is arranged in meshing engagement with said second gearset.

11. The dual-clutch transmission assembly as set forth in claim 10 wherein said third gearset and said fourth gearset have gears that are grouped together on said single intermediate shaft such that said gears of said third gearset are disposed on one side of said single intermediate shaft and said gears of said fourth gearset are disposed on an opposite side of said single intermediate shaft.

12. The dual-clutch transmission assembly as set forth in claim 10 wherein said third gearset and said fourth gearset have gears that are sequentially arranged on said single intermediate shaft such that said gears of said third gearset alternate with said gears of said fourth gearset along said single intermediate shaft.

13. The dual-clutch transmission assembly as set forth in claim 8 further comprising:
a first output gear rotatably coupled to and carried on said single intermediate shaft, wherein said first output gear, said primary first gear, and said duplicate first gear are aligned with one another, and wherein said primary first gear and said duplicate first gear are arranged in meshing engagement with said first output gear such that both said primary first gear and said duplicate first gear cooperate to drive said first output gear when said first and second clutches are engaged.

14. The dual-clutch transmission assembly as set forth in claim 13 further comprising:
a reverse gear rotatably coupled to and carried on said first layshaft;
a second gear rotatably coupled to and carried on said second layshaft;
a second output gear rotatably coupled to and carried on said single intermediate shaft; and
a reverse idler gear disposed between said reverse gear and said second output gear in meshing engagement, wherein said reverse gear, said second gear, said second output gear, and said reverse idler gear are aligned with one another, and wherein said second gear and said reverse idler gear are arranged in meshing engagement with said second output gear such that said second output gear is driven in one rotational direction by said second gear when said first clutch is disengaged and said second clutch is engaged and such that said second output gear is driven in an opposite rotational direction by said reverse idler gear when said first clutch is engaged and said second clutch is disengaged.

15. The dual-clutch transmission assembly as set forth in claim 8 further comprising:
a primary first output gear that is rotatably coupled to and carried on said single intermediate shaft and that is arranged in meshing engagement with said primary first gear;
a duplicate first output gear that is rotatably coupled to and carried on said single intermediate shaft and that is arranged in meshing engagement with said duplicate first gear;
a second gear rotatably coupled to and carried on said second layshaft;
a third gear rotatably coupled to and carried on said first layshaft;
a second output gear that is rotatably coupled to and carried on said single intermediate shaft and that is arranged in meshing engagement with said second gear; and
a third output gear that is rotatably coupled to and carried on said single intermediate

Assignees

• Avl Powertrain Engineering Inc
• Avl Power Train Eng Inc

Inventors

• Mordukhovich Gregory
• Kozan Michael

Classifications

• F16H2200/0056

  the gear ratios comprising seven forward speeds · CPC title

• F16H2003/0931

  each countershaft having an output gear meshing with a single common gear on the output shaft · CPC title

• F16H37/046

  with an additional planetary gear train, e.g. creep gear, overdrive · CPC title

• F16H3/097

  the input and output shafts being aligned on the same axis · CPC title

• F16H3/006 Primary

  power being selectively transmitted by parallel flow paths, e.g. dual clutch transmissions · CPC title