Abstract: A radiator arrangement is disclosed which avoids problems of known radiator arrangements where it is customary to manufacturer a radiator and fan unit and to subsequently connect an electric control device with the heat exchanger and the fan drive and to equip the unit with temperature sensors during assembly on a vehicle. It is disclosed to fasten the control device and the temperature sensor directly to the structural unit formed by the heat exchanger and the fan arrangement. As a result of this construction, the whole radiator arrangement can still be adjusted in the manufacturing plant prior to movement of same to a location where the radiator/fan unit is assembled on a further vehicle part.

Abstract: Disclosed is a fan drive, in particular one for cooling installations of rail vehicles. The fan drive comprises a hydraulic motor and a control valve which regulates a bypass as a function of temperature, thus affecting the flow of a pressure medium driving the motor. The control valve comprises a control piston subjected to a control pressure in the direction of closing the bypass, and a counterbalancing pressure in the opposite direction from the source of the pressure medium. The control valve also comprises a control spring which biases the control piston in the direction of closing the valve, and a pilot valve which affects the control pressure. The pilot valve is actuated by an electromechanical servo component. The pilot valve is located in an insert which is arranged within the control piston. A central bore of the control piston is slidingly guided on the convex surface of the insert so as to form a seal.