Assignment

The sequential gearbox has many advantages. Unfortunately, the gear changing operation still lasts rather long. A twin-clutch gearbox in which two gear shafts, one running inside the other, and each combined with a clutch, offers a solution without a great deal of effort. The aim is to use the components of a dry clutch. In spite of the somewhat increased space needed, it can be also installed in a transverse mounted, front-wheel drive. The gear changing can be either manual or automatic.

Function

Although we have here a non-coaxial gearbox the input shaft is divided. Whereby, the (green) shaft with the 1st, 3rd and 5th gears, runs through the (blue) hollow shaft with the 2nd, 4th and 6th gears. Each group has a clutch. The sliding collars and clutches are electrically operated.
The reason for the complexity, is the possibility of changing a gear in one group, while the torque is transferred by one gear of the other group. Without gear-changing delay through simultaneous engaging of one clutch and disengaging of the other, can the process of changing into the next gear be carried out without hesitation.

If the manual gear-change is no longer necessary, the number of gears possible is practically unlimited. Then more frequent gear-changing e.g., on the motorway, is hardly a problem at all. The advantage is, having the most favourable gear-ratio at a constant speed, which adds the benefit of a low CO₂ emission. This is the reason why the VW boss announced the introduction of up to 10 speeds. 04/13