Zf Friedrichshafen Ag

Thomas Lindner

Thilo Schmidt

Peter Ziemer

Georg Gierer

Peter Schiele

Gert Bauknecht

Peter Tiesler

Matthias List

A transmission device has at least one electro-hydraulic transmission control unit and a method of operating the transmission device having a plurality of gear wheel that can be engaged and disengaged from a force flow by fluidically actuated shifting elements. A piston space of a first shifting element, delimited by a second functional surface of the actuating piston of the first shifting element, is made separate from a piston space of a second shifting element, delimited by the first functional surface of the actuating piston, and an area of the second shifting element, that carries an actuating pressure, or an area of the first shifting element, that carries an actuating pressure, is, or can be, connected to the piston space delimited by the second functional surface of the actuating piston of the first shifting element.

Transmission device and method for operating a transmission device

A transmission device () with a hydraulic system () comprising a main transmission pump device for supplying various transmission components with hydraulic fluid. The main transmission pump device is driven by torque applied to the transmission input shaft (). A force flow between the transmission input shaft () and transmission output shaft () is produced by various hydraulically actuated transmission components. When the hydraulic system () is not supplied by the main transmission pump, the force flow is interrupted. The hydraulic system () has an auxiliary pump device () by virtue of which the hydraulic system () too can be supplied with hydraulic fluid. The auxiliary pump device () is driven by torque applied to the transmission output shaft () at least when the force flow is interrupted.

Transmission device with a hydraulic system comprising a transmission main pump apparatus

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Kressbronn, Germany

Thomas Lindner