Daimler Chrysler Ag

Daimler Ag

Albrecht Schaefer

Benjamin Kemmner

Dittmar Wieland

Benjamin Kemmerer

A clutch device for a motor vehicle has friction elements around which coolant flows and which, by way of a piston, can be pressed against one another for torque transmission. The first piston side is acted on with operating pressure, and the second piston side is acted on with coolant pressure. A valve, by which the operating pressure can be set, and a device which makes a reaction of the coolant pressure on the operating pressure possible are provided. The device is designed as a hydraulic resistance cascade and is connected between coolant supply and coolant return lines of the friction elements. A return pressure line branches off in the center of the hydraulic resistance cascade and is connected to the valve.

Coupling device

In a method for controlling the operating temperature of a hydraulic operating medium for a drive unit of a vehicle in a selected range, the operating temperature is controlled by controlling the volume flow of the operating medium for a heat exchange between the operating medium and a secondary heat transfer medium flow medium to a predetermined desired value as a function of the actual value of the operating temperature and as a function of at least one other vehicle parameter, by which a certain temperature influencing effect on the operating medium can be provided. The selected range of the operating temperature includes both the temperature values occurring in the warm-up phase of the drive unit and temperature values, which are substantially higher than the desired value.

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Uhingen, Germany

Albrecht Schaefer