Zf Friedrichshafen Ag

Rainer Denzler

Jorg Arnold

Volker Vogel

A method of operating a transmission with interlocking and friction shifting elements. In or to carry out a gearshift from a currently gear to a target gear, one shifting element is disengaged and another is engaged, and if to carry out a gearshift an interlocking shifting element has to be engaged, the interlocking shifting element is synchronized by partially closing a friction shifting element, with redundancy in the transmission, only if a current speed of the vehicle is lower than a limit value. To monitor for possible malfunction, actuation of the shifting elements and the driving speed are monitored and if, based on the actuation of the shifting elements, it is concluded that there is a redundancy in the transmission, a stored non-actual driving speed is compared with the limit value and if the stored driving speed is higher than the limit value, the redundancy in the transmission is eliminated.

Method and control device for operating a transmission

A method of detecting axial wear and a counterforce gradient of a multiple disc switching element () with position-controlled actuation with an electric motor (), a spur gear stage () and a ball ramp () by one of a hydraulic pressure actuator and an electromagnetic actuator. The method comprises the step of determining, when a vehicle is at a standstill, the axial wear (J) and the counterforce gradient or the rigidity of the system by an overrun adaptation.

Growing community of inventors

Baienfurt, Germany

Rainer Denzler