Tech special: the works in dual clutch transmissions
Posted on 08-03-2015 17:03 by MauritsH – 54 Comments”
Smooth and blazing fast clutches, to be at all times two hands on the wheel and the left foot can be on vacation: works in dual clutch transmissions.
The basis of the dual clutch transmission (hereinafter referred to as DCT) is formed by the double input shaft, of the engine to the gearbox. The outer shaft is hollow and houses the inner shaft. Each of these shafts has its own clutch and, at least equally important, is sitting on a private series of gears. Both links are also in the same clutch.
Both axles serve as said each has its own set of gears. So will the one as the ‘even’ gears, where the other person cares about the ‘odd’ gears. Actually houses a car with DCT (whether it’s PDK, DSG or whatever is called) so two gearboxes in one.
This image (click for BIG) of the 7-stage system (more gears can also, of course) that Audi, for example, on the Q5, clearly illustrates that each input shaft, separate gears for its take care of. The blue hollow shaft does the 2, 4 and 6, where the yellow axis 1, 3, 5, and 7 controls.
At the time that the manual transmission in first gear and will only the link to the yellow axis belongs to be used. That’s hardly news, in big lines, this works the same as with a conventional container with a single link.
The big trick to DCT is that the next gear (whether it be higher or lower) can be ‘prepared’. Sounds like fun, but how does that set up?
The preselecteren of the following gear
An important property of the DCT that allows the next gear to preselecten, is the fact that the gears on the output (in the image: lower) shaft can freely rotate because they are supported.
These accelerations can, in turn, be secured with so-called collars, sliding and locking components on the output shaft. This computer-controlled parts ensure that the gear ‘grabs’ and so on. For the actual drive makes that not matter, because the torque is still about the coupling of the gear will be sent, which at that time effectively the drive for z’n (in our example: the first gear).
Switch to the next/previous resistance
The software (or the triggerhappy flipperaar) now to the second gear, the computer ensure that the first clutch is disengaged and the second his work. This means there is no interruption in the power supply, because the actual switch is already long and wide back.
For on – and down goes the same. The ‘baksoftware predicts on the basis of various factors, or the next or the previous gear at that moment, so desired and choose accordingly, one of the two. Smoothly, quickly, and unfortunately emotionless, but therefore not less efficient.
That the development of the DCT’s without prejudice to losing, was probably already clear. Cars like the 991 GT3 (pdk) shine their work so well that the lack of a manual gearbox on the options list by some journalists does not even more as a loss is seen. Volkswagen was also the first that a ‘bucket with dual clutch in a production car used. It was the Golf IV R32 with the eea should be ironed.