Twin clutch manual gearbox

• US 20060174722A1
• Filed: 03/21/2005
• Published: 08/10/2006
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Terai, Hiromu
• Granted Patent: US 7,434,487 B2
• Time in Patent Office: Days
• US Class Current: 74/325
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: Y10T 74/19219 Interchangeably locked
• CPC Class Codes: Y10T 74/19228 Multiple concentric clutch shafts
• CPC Class Codes: Y10T 74/19288 Double clutch and interposed transmission

Abstract

A twin-clutch manual gearbox has a first input shaft and a second input shaft to which engine rotation is selectively input via individual clutches. The second input shaft is rotatably fitted onto the first input shaft so that the first input shaft protrudes from an end of the second input shaft farthest from the engine. First gearsets are located between the protruding end of the first input shaft and a layshaft located between the first and second input shafts. Second gearsets are located between the second input shaft and the layshaft. The second gearsets are positioned such that the gearset of the lowest gearbox speed which is capable of providing a bearing retaining space between the first input shaft and the second input shaft is positioned farthest from the engine, and the gearset of the highest gearbox speed is positioned closest to the engine.

Claims

1. A twin-clutch manual gearbox for an engine, the gearbox including:

a first input shaft and a second input shaft to which engine rotation is selectively input via individual clutches, the second input shaft being rotatably fitted onto the first input shaft so that the first input shaft protrudes from a rearward end of the second input shaft farthest from the engine,

first gearsets associated with a first gearbox speed grouping, the first gearsets being located between the rearward end of the protruding first input shaft and a layshaft located substantially parallel to the first and second input shafts such that appropriate transmission is enabled for respective ones of the first gearsets,

second gearsets associated with a second gearbox speed grouping, the second gearsets being located between the second input shaft and the layshaft such that appropriate transmission is enabled for respective ones of the second gearsets, whereby rotation according to a selected gear after a gearchange is output in an axial direction from a rearward end of the first input shaft or of the layshaft,

the twin-clutch manual gearbox being characterized in that the second gearsets are positioned such that the gearset associated with the lowest gearbox speed of the second gearbox speed grouping capable of providing a bearing retaining space between the first input shaft and the second input shaft is positioned so as to be farthest from the engine, and the gearset associated with the highest gearbox speed of the remaining gearbox speeds of the second gearbox speed grouping is positioned so as to be closest to the engine.

2. The twin-clutch manual gearbox as claimed in claim 1, wherein

the second input shaft is hollow for receiving a forward end of the first input shaft, thereby to define the bearing retaining space therebetween for housing a bearing for a gearset of the second gearbox speed grouping.

3. The twin-clutch manual gearbox as claimed in claim 1, wherein

the second gearbox speed grouping includes a further gearset associated with a gearbox speed intermediate the lowest and highest gearbox speeds, and the further gearset being positioned intermediate the gearset associated with the lowest gearbox speed and the gearset associated with the highest gearbox speed.

4. The twin-clutch manual gearbox as claimed in claim 1, wherein

the second gearsets associated with the remaining gearbox speeds of the second gearbox speed grouping are further positioned in accordance with the following criteria:

(i) between a gearset associated with a gearbox speed positioned farthest from the engine and a gearset associated with a gearbox speed positioned closest to the engine and (ii) in such a manner that gearsets associated with higher gearbox speeds are positioned closer to the engine.

5. The twin-clutch manual gearbox as claimed in claim 1, wherein

the gearsets of the second gearbox speed grouping provided between the second input shaft and the layshaft form an even-numbered gearbox speed grouping.

6. The twin-clutch manual gearbox as claimed in claim 5, wherein

a fourth gear gearset is positioned farthest from the engine.

7. The twin-clutch manual gearbox as claimed in claim 6, wherein

a sixth gear gearset is positioned closest to the engine and a second gear gearset is positioned intermediate the fourth and sixth gear gearsets.

8. The twin-clutch manual gearbox as claimed in claim 1, wherein

the first gearsets of the first gearbox speed grouping form an odd-numbered gearbox speed grouping.

9. The twin-clutch manual gearbox as claimed in claim 1, wherein

the first and second shafts and the layshaft constitute a shaft arrangement, the twin-clutch manual gearbox further comprising at least one interlocking mechanism for enabling, respectively, appropriate transmission of gearsets associated with the second gearbox speed grouping.

10. The twin-clutch manual gearbox as claimed in claim 9, further comprising

a plurality of interlocking mechanisms for enabling, respectively, appropriate transmission of gearsets associated with the second gearbox speed grouping, wherein the plurality of interlocking mechanisms is provided between the second input shaft and the layshaft on a layshaft side of the shaft arrangement.

11. The twin-clutch manual gearbox as claimed in claim 10, wherein

one of the interlocking mechanisms is a specialized interlocking mechanism for enabling appropriate transmission of the gearset positioned closest to the engine, and wherein the specialised interlocking mechanism is positioned between the gearset positioned closest to the engine and a gearset positioned adjacent to the gearset.

12. The twin-clutch manual gearbox as claimed in claim 11, wherein

the second gearsets associated with the second gearbox speed grouping form a grouping of a second gear gearset, a fourth gear gearset and a sixth gear gearset, and wherein the fourth gear gearset is positioned on a side of the layshaft farthest from the engine, the sixth gear gearset is positioned on a side of the layshaft closest to the engine, the second gear gearset is positioned in between the fourth and sixth gear gearsets, an interlocking mechanism common to the second gear gearset and the fourth gear gearset is positioned between the second gear gearset and the fourth gear gearset, and a specialized interlocking mechanism for the sixth gear gearset is positioned between the second gear gearset and the sixth gear gearset.

13. The twin-clutch manual gearbox as claimed in claim 12, wherein

the sixth gear gearset comprises, in a mutually interlocking manner, a sixth gear input gear which is formed as one unit onto an outer diameter of the second input shaft, and a sixth gear output gear which is rotatably provided on the layshaft, the second gear gearset comprises, in a mutually interlocking manner, a second gear input gear which is formed as one unit onto the outer diameter of the second input shaft, and a second gear output gear which is rotatably provided on the layshaft, and the fourth gear gearset comprises, in a mutually interlocking manner, a fourth gear input gear which is formed as a single unit onto the outer diameter of the second input shaft and a fourth gear output gear which is rotatably provided on the layshaft.

14. The twin-clutch manual gearbox as claimed in claim 1, wherein

the layshaft has a maximum diameter approximately at a midway point.

15. The twin-clutch manual gearbox as claimed in claim 14, wherein

the midway point is at a position equivalent to a boundary between the second gearsets and the first gearsets.

16. A vehicle having an engine fitted with a twin-clutch manual gearbox as claimed in claim 1.

17. The twin-clutch manual gearbox as claimed in claim 2, wherein

the second gearbox speed grouping includes a further gearset associated with a gearbox speed intermediate the lowest and highest gearbox speeds, and the further gearset being positioned intermediate the gearset associated with the lowest gearbox speed and the gearset associated with the highest gearbox speed.

18. The twin-clutch manual gearbox as claimed in claim 2, wherein

the second gearsets associated with the remaining gearbox speeds of the second gearbox speed grouping are further positioned in accordance with the following criteria:

(i) between a gearset associated with a gearbox speed positioned farthest from the engine and a gearset associated with a gearbox speed positioned closest to the engine and (ii) in such a manner that gearsets associated with higher gearbox speeds are positioned closer to the engine.

19. The twin-clutch manual gearbox as claimed in claim 2, wherein

the gearsets of the second gearbox speed grouping provided between the second input shaft and the layshaft form an even-numbered gearbox speed grouping.

20. The twin-clutch manual gearbox as claimed in claim 2, wherein

the first and second shafts and the layshaft constitute a shaft arrangement, the twin-clutch manual gearbox further comprising at least one interlocking mechanism for enabling, respectively, appropriate transmission of gearsets associated with the second gearbox speed grouping.