The dual clutch gearbox is used quite frequently. It's quite incredible how sports cars can accelerate without the traction force being interrupted by changing through the individual gears. It's high time for us to show a sectional image which points out more of the technical solutions. Here's one from a BorgWarner gearbox developed for VW, which was one of the first on the market.
How it works
If we start on top left with the colour Yellow, we can see a cross section of the 2-dimensional flywheel, which continues to the right to the hydraulically operated dual-clutch. This hardly takes up more space than the foot-operated single-disk dry clutch. All the functions of this gearbox are controlled and operated hydraulically. Next we see, on the right beside the clutch, the gear-change. In each case two pistons are arranged opposite to each other. The piston currently being supplied with oil pressure moves the sliding clutch in a certain direction. The partner piston is, at this point, without pressure. The four pistons visible here, can change four gears.
In front, on the right, in the black casing, along with electronics, all the pressure production and also some of the electro-magnetic valve control-system is arranged. Right up front, the electrically operated high-pressure pump is visible. Parts of the control system are accommodated above the final drive, probably due to lack of space elsewhere. In addition, on the far left we can see two further control valves. 09/08