Double clutch transmission having a layshaft design

Patent metadata

Field	Value
Publication number	US-9021906-B2
Application number	US-201113822006-A
Country	US
Kind code	B2
Filing date	Aug 3, 2011
Priority date	Sep 13, 2010
Publication date	May 5, 2015
Grant date	May 5, 2015

Abstract

A double clutch transmission of countershaft design having a central shaft and a concentric hollow transmission shaft, one countershaft, and two power-shift elements. Two hollow shafts are disposed on the countershaft coaxially to the countershaft, each of which can be fixed, via one shift device, to the countershaft, and to which at least two gearwheels are fixed. A further hollow shaft is coaxially provided on either the central or hollow transmission shafts and can be connected, via a shift device, to the central or hollow transmission shaft, and to which at least two further gearwheels of the gear stages are fixed. At least three transmission ratios are possible by engaging three of the gear stages on the shift-element side into the power flow, thereby enabling one transmission ratio to be at least partially implemented by a respective sole engagement on the shift-element side into the power flow.

First claim

The invention claimed is:

1. A double clutch transmission ( 1 ) having a countershaft design, the double clutch transmission comprising:
a central transmission shaft ( 2 ) and a hollow transmission shaft ( 3 ) disposed concentrically thereto, exactly one countershaft ( 4 ), and first and second power-shift elements (K 1 , K 2 );
both of the first and the second power-shift elements (K 1 , K 2 ) being operatively connectable, on a drive side thereof, with a drive assembly;
one of the first and the second power-shift elements (K 2 ) being connected, on an output side thereof, to the central transmission shaft ( 2 );
the other of the first and the second power-shift elements (K 1 ) being connected to the hollow transmission shaft ( 3 );
the central transmission shaft ( 2 ) and the hollow transmission shaft ( 3 ) being connectable to the countershaft ( 4 ) to implement a transmission ratio (“1”) via gear stages (ZP 2 to ZPR), which are engagable into and disengageable from a power flow, by a plurality of shift devices (SE 1 to SE 5 );
at least two of the gear stages ((ZP 6 , ZP 2 ), (ZP 2 , ZP 4 ), (ZP 7 , ZP 5 ), (ZP 5 , ZP 9 ), ZP 3 , ZPR); (ZP 2 , ZP 6 ), (ZP 6 , ZP 8 ), (ZP 7 , ZP 5 ), (ZP 5 , ZP 9 ), (ZP 3 , ZPR)) are assigned to the plurality of shift devices (SE 1 to SE 5 ), respectively;
first and second hollow shafts ( 8 A, 8 B) being provided on the countershaft ( 4 ) and being disposed coaxially to one another, each of the first and the second hollow shafts is coupleable, in a rotationally fixed manner, to the countershaft ( 4 ) via one of the plurality of shift devices (SE 1 or SE 3 ), and to which at least two gearwheels ( 21 or 61 , 41 or 81 , 51 , 91 ) of the gear stages (ZP 2 or ZP 6 , ZP 4 or ZP 8 , ZP 5 , ZP 9 ), respectively, are connected in a rotationally fixed manner;
a further hollow shaft ( 9 A) being provided on either the central transmission shaft ( 2 ) or the hollow transmission shaft ( 3 ), and being disposed coaxially thereto, the further hollow shaft being connectable, via one of the plurality of shift devices (SE 2 ), to either the central transmission shaft ( 2 ) or the hollow transmission shaft ( 3 ), and to which at least two further gearwheels ( 22 , 61 ) of the gear stages (ZP 2 , ZP 6 ) are connected in a rotationally fixed manner; and
at least three transmission ratios (“1”, “8”, “R”; “1”, “4”, “R”) are implemented by selective engagement of three of the gear stages ((ZP 5 , ZP 9 , ZP 3 ), (ZP 4 , ZP 2 , ZP 6 ), (ZP 5 , ZP 9 , ZPR); (ZP 5 , ZP 9 , ZP 3 ), (ZP 8 , ZP 6 , ZP 2 ), (ZP 5 , ZP 9 , ZPR)), respectively, on a shift-element side into the power flow thereby enabling one transmission ratio (“2”, “3”, “4”, “5”, “6”, “9”; “2”, “3”, “5”, “6”, “8”, “9”), respectively, to be at least partially implemented by a respective sole engagement on the shift-element side into the power flow.

2. The double clutch transmission according to claim 1 , wherein the central transmission shaft ( 2 ) or the hollow transmission shaft has a divided design, and a first transmission subshaft ( 2 A) of the central transmission shaft ( 2 ) or the hollow transmission shaft is coupleable to a second transmission subshaft ( 2 B) of the central transmission shaft ( 2 ) or the hollow transmission shaft via one of the plurality of shift devices (SE 4 ), and one of the first and the second transmission subshafts ( 2 A) of the two shift-element halves is connected to the output side of one of the first and the second power-shift elements (K 1 ),
three of the gear stages (ZP 9 , ZP 3 , ZP 6 ) are coupled to one of the first and the second transmission subshafts ( 2 B), another of the gear stages (ZP 7 ) is coupleable to or is connected to the other of the first and the second transmission subshafts ( 2 A), via one of the plurality of shift devices (SE 4 ), and an additional gear stage (ZP 5 ) is coupleable, via the one of the plurality of shift devices (SE 4 ), to the other of the first and the second transmission subshaft ( 2 B).

3. The double clutch transmission according to claim 1 , wherein the further hollow shaft supports three of the gear stages,
while another gear stage is connectable or is connected to the central transmission shaft or the hollow transmission shaft via one of the plurality of shift devices, and an additional gear stage is coupleable to the central transmission shaft or the hollow transmission shaft via one of the plurality of shift devices.

4. The double clutch transmission according to claim 2 , wherein an additional hollow shaft ( 9 B) is disposed on the central transmission shaft ( 2 ) or the hollow transmission shaft ( 3 ), the additional hollow shaft ( 9 B) is coupleable thereto via one of the plurality of shift devices (SE 4 ), and a gearwheel ( 71 , 52 ) of the further gear stage (ZP 7 ) and the additional gear stage (ZP 5 ) are connected to the additional hollow shaft ( 9 B) in a rotationally fixed manner.

5. The double clutch transmission according to claim 2 , wherein the further gear stage (ZP 7 ) is disposed between the first and the second power-shift elements (K 1 , K 2 ) and the additional gear stage (ZP 5 ).

6. The double clutch transmission according to claim 2 , wherein one gear stage (ZP 3 ), of the three gear stages (ZP 9 , ZP 3 , ZPR), is disposed in a middle between the two other gear stages (ZP 9 and ZPR) relative to an axial extension of the central transmission shaft ( 2 ).

7. The double clutch transmission according to claim 6 , wherein an outer gear stage (ZPR), of the three gear stages (ZP 9 , ZP 3 , ZPR) disposed on the side of the central gear stage (ZP 3 ), faces away from the first and the second power-shift elements (K 1 , K 2 ), relative to the axial extension of the central transmission shaft ( 2 ).

8. The double clutch transmission according to claim 6 , wherein the further gear stage (ZP 7 ) is disposed between the central gear stage (ZP 3 ) of the three gear stages (ZP 9 , ZP 3 , ZPR) and an outer gear stage (ZP 9 ) of the three gear stages (ZP 9 , ZP 3 , ZPR), is disposed on the side which faces the first and the second power-shift elements (K 1 , K 2 ) in the axial extension of the central transmission shaft ( 2 ).

9. The double clutch transmission according to claim 1 , wherein two of the three gear stages ((ZP 5 , ZP 9 , ZP 3 ) or (ZP 5 , ZP 9 , ZPR)), which should be engaged into the power flow in order to implement two transmission ratios (“1”, “R”) are identical, and the third gear stage (ZP 3 or ZPR) varies.

10. The double clutch transmission according to claim 1 , wherein four of the gear stages (ZP 6 , ZP 7 , ZP 3 , ZPR; ZP 2 , ZP 7 , ZP 3 , ZPR) are operatively connected to the countershaft ( 4 ) by shift devices (SE 1 , SE 3 , SE 5 ).

11. The double clutch transmission according to claim 1 , wherein one of the gear stages (ZP 6 ; ZP 2 ), via which either a sixth or a second transmission ratio (“6”, “2”) for forward travel is implemented, is coupleable via one of the plurality of shift devices (SE 2 ) to the central transmission shaft ( 2 ) or the hollow transmission shaft ( 3 ) and, via another of the plurality of shift devices (SE 1 ), to the countershaft ( 4 ).

12. The double clutch transmission according to claim 1 , wherein one gearwheel ( 61 , 22 , 42 or 82 ) of three of the gear stages (ZP 6 , ZP 2 , ZP 4 ; ZP 2 , ZP 6 , ZP 8 ) is coupleable, via one of the shift devices (SE 2 ), to the central transmission shaft ( 2 ) or the hollow transmission shaft ( 3 ), and one gearwheel ( 71 , 52 , 92 , 31 , 12 ) of five further gear stages (ZP 7 , ZP 5 , ZP 9 , ZP 3 , ZPR) is coupleable, via another one of the plurality of shift devices (SE 4 ), to the hollow transmission shaft ( 3 )

Assignees

• Dreibholz Ralf
• Wafzig Juergen
• Wechs Michael
• Renninger Markus
• Rosemeier Thomas
• Kaltenbach Johannes
• Kauffeldt Rudolf
• Zahnradfabrik Friedrichshafen

Inventors

• Dreibholz Ralf
• Wafzig Juergen
• Wechs Michael
• Renninger Markus
• Rosemeier Thomas
• Kaltenbach Johannes
• Kauffeldt Rudolf

Classifications

• Y02T10/626

  Cross-Sectional Technologies · mapped topic

• B60K2006/4825

  Electric machine connected or connectable to gearbox input shaft · CPC title

• F16H3/006 Primary

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

• F16H3/083

  with radially acting and axially controlled clutching members, e.g. sliding keys · CPC title

• Y02T10/6252

  Cross-Sectional Technologies · mapped topic