Dual Clutch Powershift Transmission

Abstract

An automated dual-clutch multi-speed transmission is adapted to transfer power from an engine to the driveline of a motor vehicle. The transmission includes an output shaft adapted for connection to the driveline, an input shaft continuously driven by the engine and offset from a position substantially parallel to the output shaft. A countershaft is in constant driving engagement with the output shaft and is offset from and positioned substantially parallel to the input and output shafts. A first clutch is operable for establishing a releasable drive connection between the input shaft and a first driven shaft. A second clutch is operable for establishing a releasable drive connection between the input shaft and a second driven shaft. First and second gearset clutches are operable to releasably drivingly couple first and second gearsets to the countershaft.

Description

DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a schematic view of a dual-clutch automated transmission according to the present invention;

FIG. 2 is a diagrammatic illustration of a transmission control system adapted for use with the dual-clutch automated transmission shown in FIG. 1;

FIG. 3 is a cross-sectional view of the dual-clutch automated transmission shown in FIG. 1; and

FIG. 4 is a schematic view of an alternate embodiment dual-clutch automated transmission operable to provide output torque to front and rear output shafts.

Claims

1. A dual-clutch transmission for use in a motor vehicle having an engine and a driveline, comprising: an output shaft adapted for connection to the driveline;an input shaft continuously driven by the engine, the input shaft being offset from and positioned substantially parallel to the output shaft;a countershaft in constant driving engagement with the output shaft, the countershaft being offset from and positioned substantially parallel to the output shaft and the input shaft;a first clutch operable for establishing a releasable drive connection between the input shaft and a first driven shaft;a second clutch operable for establishing a releasable drive connection between the input shaft and a second driven shaft;a first constant mesh gearset being driven by the first driven shaft;a second constant mesh gearset being driven by the second driven shaft; andfirst and second gearset clutches, the first gearset clutch being operable to releasably drivingly couple the first gearset and the countershaft, the second gearset clutch being operable to releasably drivingly couple the second gearset and the countershaft.

2. The dual-clutch transmission of claim 1 further comprising a third constant mesh gearset being driven by the first driven shaft and a fourth constant mesh gearset being driven by the second driven shaft.

3. The dual-clutch transmission of claim 2 wherein the first gearset clutch is operable to releasably drivingly couple the third gearset and the countershaft, the second gearset clutch being operable to releasably drivingly couple the fourth gearset and the countershaft.

4. The dual-clutch transmission of claim 3 further including a fifth gearset being driven by the first driven shaft and a sixth gearset being driven by the second driven shaft.

5. The dual-clutch transmission of claim 4 further including a third gearset clutch being operable to releasably drivingly couple the fifth gearset and the countershaft and a fourth gearset clutch being operable to releasably drivingly couple the sixth gearset and the countershaft.

6. The dual-clutch transmission of claim 5 further including a reverse gearset being driven by the first driven shaft, the third gearset clutch being operable to releasably drivingly couple the reverse gearset and the countershaft.

7. The dual-clutch transmission of claim 1 further including a controller for controlling actuation of the first and second clutches.

8. The dual-clutch transmission of claim 7 further including first and second actuators controlling the first and second clutches, respectively, the controller controlling actuation of the first and second actuators.

9. The dual-clutch transmission of claim 8 wherein the first and second gearset clutches are electrically-actuated dog clutches.

10. The dual-clutch transmission of claim 1 wherein the first driven shaft concentrically encompasses a portion of the input shaft.

11. The dual-clutch transmission of claim 10 wherein the second driven shaft concentrically encompasses a portion of the input shaft.

12. The dual-clutch transmission of claim 1 wherein the first clutch is positioned at one end of the input shaft and the second clutch is positioned at an opposite end of the input shaft.

13. The dual-clutch transmission of claim 1 wherein the first and second clutches are normally closed clutches operable to transmit torque without an application of external force.

14. The dual-clutch transmission of claim 1 wherein the output shaft has a first end adapted to provide torque to a first set of driven wheels and a second end adapted to provide torque to a second set of driven wheels.

15. The dual-clutch transmission of claim 1 further including a differential in constant driving engagement with the countershaft, the differential providing torque to the output shaft and another shaft adapted for connection with another driveline.

16. A dual-clutch transmission for use in a motor vehicle having an engine and a driveline, comprising: an input shaft continuously driven by the engine;an output shaft adapted for connection to the driveline and having a first output gear fixed thereto;a countershaft having a second output gear fixed thereto in meshed engagement with the first output gear;a first clutch operable for establishing a releasable drive connection between the input shaft and a first substantially tubular shaft having a first drive gear fixed thereto, the first tubular shaft concentrically encompassing a portion of the input shaft;a second clutch operable for establishing a releasable drive connection between the input shaft and a second substantially tubular shaft, the second tubular shaft concentrically encompassing a portion of the input shaft and having a second drive gear fixed thereto;first and second speed gears rotatably supported on the countershaft, the first speed gear being in meshed engagement with the first drive gear and the second speed gear being in meshed engagement with the second drive gear; andfirst and second speed gear clutches, the first speed gear clutch being operable to releasably drivingly couple the first speed gear and the countershaft, the second speed gear clutch being operable to releasably drivingly couple the second speed gear and the countershaft.

17. The dual-clutch transmission of claim 16 wherein the first clutch is positioned at one end of the input shaft and the second clutch is positioned at an opposite end of the input shaft.

18. The dual-clutch transmission of claim 17 further including a controller for controlling actuation of the first and second clutches.

19. The dual-clutch transmission of claim 18 further including first and second actuators controlling the first and second clutches, respectively, the controller controlling actuation of the first and second actuators.

20. The dual-clutch transmission of claim 16 wherein the first and second substantially tubular shafts have ends supported by a center web of a housing rotatably supporting the output shaft.

21. The dual-clutch transmission of claim 20 wherein the output shaft, the input shaft and the countershaft each extend along spaced apart parallel axes.

22. The dual-clutch transmission of claim 16 further including third, fourth, fifth and sixth speed gears rotatably supported by the countershaft as well as a third drive gear fixed to the first tubular shaft and meshed with the third speed gear, a fourth drive gear fixed to the second tubular shaft and meshed with the fourth speed gear, a fifth drive gear fixed to the first tubular shaft and meshed with the fifth speed gear, and a sixth drive gear fixed to the second tubular shaft and meshed with the sixth speed gear.

23. The dual-clutch transmission of claim 16 wherein the first and second clutches are normally closed clutches operable to transmit torque without an application of external force.

24. A dual-clutch transmission for use in a motor vehicle having an engine, a front driveline, and a rear driveline, the transmission comprising: a first output shaft adapted for connection to the front driveline;a second output shaft adapted for connection to the rear driveline;an input shaft driven by the engine, the input shaft being offset from and positioned substantially parallel to the first and second output shafts;a countershaft in constant driving engagement with the first and second output shafts;a first clutch operable for establishing a releasable drive connection between the input shaft and a first driven shaft;a second clutch operable for establishing a releasable drive connection between the input shaft and a second driven shaft;a first constant mesh gearset driven by the first driven shaft;a second constant mesh gearset driven by the second driven shaft; andfirst and second gearset clutches, the first gearset clutch being operable to releasably drivingly couple the first gearset and the countershaft, the second gearset clutch being operable to releasably drivingly couple the second gearset and the countershaft.

25. The dual-clutch transmission of claim 24 further including a differential having a case driven by the countershaft, a first side gear being fixed to the first output shaft and a second side gear being fixed to the second output shaft.

26. The dual-clutch transmission of claim 25 wherein the case is coupled to a third tubular shaft concentrically encompassing a portion of one of the first and second output shafts.

27. The dual-clutch transmission of claim 26 further comprising a third constant mesh gearset being driven by the first driven shaft and a fourth constant mesh gearset being driven by the second driven shaft.

28. The dual-clutch transmission of claim 27 wherein the first gearset clutch is operable to releasably drivingly couple the third gearset and the countershaft, the second gearset clutch being operable to releasably drivingly couple the fourth gearset and the countershaft.