Direct-shift-gearbox derived from the compact-construction gearbox
The non-equiaxial six-speed gearbox is, in the case of the transverse mounted front engine, particularly well suited as a direct gear box (Direct Shift Gearbox) because it already has the necessary number of gearwheels and sliding clutches. Only the speeds must be changed, then the dual-clutch gearbox is complete. In this case it is combined with a dual-clutch.
An Expanded view is preferred, but more difficult to understand
The representation of the functions is difficult, actually the compact-construction gearbox, should be shown three-dimensionally. Click on the buttons to be able to better understand the true situation of both upper and lower drive shafts and the sliding clutches. They end in two different sized, large gearwheels (immediately beside the clutch) which deliver the torque to the spur gear of the final drive. The gear ratio of the reverse gear is also shown, more complicated, but also more realistic, here.
The activity of the dual-clutch has been left out, for a better understanding. This can be studied here.
The right sliding clutch on the lower (rear) shaft is shifted to the right and transfers the torque, because the green multiple-disc clutch has been engaged. Almost at the same time the left sliding clutch on the lower (rear) shaft was already shifted in preparation, to the left.
The blue multiple-disc clutch is the one, that disengages the green one. That way, the second gear is engaged without a break. In preparation for the third gear, the right sliding clutch is shifted to the left.
Again a clutch change, and afterwards, for the preparation of the fourth gear, the left sliding clutch is shifted. The first four speeds are transferred through the lower (rear) shaft and the smaller spur gear to the final drive.
If the blue clutch is now engaged again, the lower rear shaft is included in the power transmission for the last time. On the upper (rear) shaft the right sliding clutch is already preparing for the use of the fifth gear.
Now the upper (rear) shaft which is also connected, through a larger spur gear, with the final drive, is involved in the other gears. The right sliding clutch transfers the torque, the left one is engaged for the sixth gear.
The highest gear is reached. Actually, one could leave the sliding clutch of the fifth gear as it is. The zero position should make it clear that here no further preparation is necessary.
Not only three shafts and mutually, meshing gearwheels are found in the compact-construction gearbox. A fourth one provides for the change in the rotary direction. Of this, one sees only the circulation wheel between both gearwheels which are positively connected by the left sliding clutch to the upper rear shaft. While driving in reverse the first gear can be already engaged so that, to drive forwards again, only the clutch must be changed. 09/08