Abstract: A clutch arrangement (1) for transmitting a drive torque from a drive shaft (2) to a secondary assembly, in particular to a fan wheel (11) of a motor vehicle, comprising a drive shaft (2), an output (10) and a friction disc clutch (12) which can be shifted by means of an electromagnetic arrangement (13). The clutch arrangement (1) comprises, in addition to the friction disc clutch (12) for transmitting torque from the drive shaft (2) to the output (10), a fluid friction clutch (4) whose hydraulic control valve (5) can be actuated by means of the electromagnetic arrangement (13) of the friction disc clutch (12) in order to set the slip.

Abstract: The present invention provides a fluid clutch which can prevent the occurrence of ‘a drag phenomenon’ in various conditions so that a fan noise can be reduced and the reduction of fuel expense is enhanced.

Abstract: An automatic coupling has two parts supported inside one another, and which are rotatable around a common longitudinal axis. The parts form an annular chamber. An annular piston axially divides the annular chamber into two compartments. The annular piston is connected to one of the parts in a rotationally fast and axially movable way and there is formed a shear channel which extends helically relative to the longitudinal axis. The shear channel connects the two compartments separated by the annular piston to one another. The end faces of the annular chamber are formed by the other one of the parts, with the annular piston being able to support itself on the end faces of the annular chamber while generating braking forces.