Dual clutch transmission

Patent metadata

Field	Value
Publication number	US-9714698-B2
Application number	US-201314439492-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Oct 30, 2012
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A shifting device for a dual clutch transmission as a speed-change transmission for motor vehicles, including two coaxially arranged input shafts, each being activatable via a clutch, an axially parallel output shaft and gearwheel sets that are mounted on the shafts and can be shifted by means of shifting clutches to allow a plurality of forward gears and a reverse gear, the gearwheel sets being subdivided into a sub-transmission having the one input shaft and a sub-transmission having the other input shaft. To achieve a wider gear-ratio spread in a structurally compact construction, a planetary gear train that can be shifted between two gear ratio stages is mounted upstream of the sub-transmission having the hollow input shaft.

First claim

The invention claimed is:

1. A shifting device for a dual clutch transmission as a change-speed transmission for motor vehicles, comprising:
two coaxially arranged input shafts which are respectively activatable via one of two clutches of a dual clutch;
an output shaft;
gearwheel sets arranged on the input shafts which are shiftable by means of synchronizing clutches for forming a plurality of forward gears and a reverse gear, said gearwheel sets being divided into a first subtransmission comprising one of the input shafts and a second subtransmission comprising the other one of the input shafts; and
a planetary transmission, which is shiftable between at least two transmission stages and is arranged upstream of one of the first and second subtransmissions, and which has an input element, an output element and a transmission element, said input element being permanently drivingly connected with a housing of the dual clutch,
wherein for shifting into a first one of the transmission stages the transmission element is fixable via a brake, and for shifting into a second one of the transmission stages the transmission element is connectable with the input element via one of the clutches,
wherein the planetary transmission is shifted to a further 1:1 transmission stage when the dual clutch is engaged and the brake is disengaged, and
wherein the change-speed transmission has eight forward gears, of which a first and a second forward gear, a fourth and a fifth forward gear, and a seventh and an eighth forward gear, are assigned to the first subtransmission with the upstream arranged planetary transmission and the third and sixth forward gear are assigned to the second subtransmission.

2. The shifting device of claim 1 , wherein the planetary transmission is shifted between the two transmission stages.

3. The shifting device of claim 1 , wherein the planetary transmission is shifted into a further lower or higher transmission stage relative to the first stage when the clutch is disengaged and the brake is engaged.

4. The shifting device of claim 1 , wherein the input element is constructed as a first sun gear the output element, is constructed as a second sun gear, and transmission element is constructed as a web on which multi-stage planet gears are supported, which are in engagement with the first and second sun gears.

5. The shifting device of claim 1 , wherein the planetary transmission is configured as a minus transmission, said minus transmission including intermeshing planet gears.

6. The shifting device of claim 5 , wherein the planetary transmission has a transmission ratio of i 0 =−3.

7. The shifting device of claim 5 , wherein the input element is a first sun gear in continuous driving relation via the housing of the dual clutch, wherein the output element is constructed as a web having multi-stage first planet gears in engagement with the first sun gear and second planet gears supported on the web, said transmission element constructed as a second sun gear meshing with the second planet gears.

8. The shifting device of claim 7 , wherein the second sun gear is drivable via the clutch for forming a 1:1 transmission ratio, or is blockable via the brake for shifting to a lower/higher transmission ratio.

9. The shifting device of claim 1 , wherein the change speed-transmission has more than eight forward gears, wherein a ninth gear is assigned to the second subtransmission via a further gearwheel set and forward gears 10 and 11 are assigned to the first subtransmission via the further gearwheel set.

10. The shifting device of claim 1 , wherein one of the gearwheel sets has an intermediate gearwheel and is assigned to the first subtransmission for forming two reverse gears.

11. The shifting device of claim 10 , wherein one of the gearwheel sets with the intermediate gearwheel is arranged in the second subtransmission to form the reverse gear.

12. The shifting device of claim 1 , wherein the one of the clutches of the dual clutch is arranged in a force flux direction downstream of the other one of the clutches of the dual clutch and the brake.

13. The shifting device of claim 1 , wherein a drive component, of an output stage protrudes into a free space.

14. The shifting device of claim 13 , wherein the drive component is a spur gear.

15. The shifting device of claim 1 , wherein the brake is arranged in a force flux direction downstream of the other one of the clutches of the dual clutch.

16. The shifting device of claim 1 , wherein the brake is arranged in a force flux direction upstream of the one of the clutches of the dual clutch.

17. The shifting device of claim 1 , wherein the other one of the clutches of the dual clutch is arranged in a force flux direction upstream of the brake and the one of the clutches of the dual clutch.

18. The shifting device of claim 17 , wherein the one of the clutches of the dual clutch is arranged in a force flux direction upstream of the brake.

19. The shifting device of claim 1 , wherein the planetary transmission comprises an outer ring gear, and an intermediate hollow shaft which is coaxially arranged on the input shaft, with one of the synchronizing clutches being arranged on the intermediate hollow shaft, said intermediate hollow shaft being connectable via the one of the synchronizing clutches with one of a forward gear gearwheel set, wherein the forward gear gearwheel set is connectable via the one of the synchronizing clutches for shifting of the reverse gear, as the clutch is disengaged and the brake is engaged.

20. The shifting device of claim 1 , wherein a further forward gear gearwheel set is shiftable via the synchronizing clutch arranged on the intermediate hollow shaft when the clutch is engaged and the brake is disengaged.

Assignees

• Audi Ag

Inventors

• Märkl Johann
• Heitmann Axel
• Hummel Steffen
• Vollmer Frank
• Schmidt Alexander

Classifications

• F16H2200/0065

  the gear ratios comprising nine forward speeds · CPC title

• F16H2200/0017

  specially adapted for four-wheel-driven vehicles · CPC title

• F16H2200/0086

  the gear ratios comprising two reverse speeds · CPC title

• F16H2200/0073

  the gear ratios comprising eleven forward speeds · CPC title

• F16H37/046 Primary

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