PSG – The Automatic Transmission of the Future Twin Clutch Transmission with Dry Clutches

Authors

Dr. W. Reik, Dr. R. Fischer, Dr. B. Pollak, Dipl.-Ing. G. Schneider, Dr. R. Berger, LuK GmbH & Co., Bühl

Year

2003

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 539

Summary

Based on manual transmissions a class of automated manual transmission (XSG) is introduced. The focus is on Power-Shift-Gearboxes PSG, that is a twin clutch transmission using dry clutches and actuators with electric motors and reduced effort using Active Interlock. Due to the power shifts excellent comfort is reached and at the same time the fuel consumption is reduced. As major component a dry twin clutch is shown. The actuators for the clutches and the transmission are built with brushless motors. This gives higher dynamics and higher forces and a very compact solution. Measurement data of a prototype vehicle show the shift quality respectively the torque fill. Theoretical estimations and measurement data as well as simulations are used to derive fuel consumption data. A 15% improvement compared to known automatic transmissions is possible. The advantages using dry clutches are shown based on a comparison of the losses of the different systems. The improved efficiency of the XSG’s improves the acceleration capabilities while the fuel consumption is reduced. Finally it is shown, how a PSG can be extended to a mild-hybrid by adding an electrical machine. Start-Stop and recuperation reduce the fuel consumption further. Integrating the air conditioning compressor gives a straight forward possibility for cooling at stillstand. Furthermore an easy way to incorporate all wheel drive is possible.

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