Hydraulic fan drive for cooling system of e.g. diesel engine of mobile operating machine, has variable flow pump driven by diesel engine, where drive is disconnected in dependence of load and rotation speed of diesel engine

摘要

The drive has a variable flow pump (20) driven by a diesel engine (18), and a fixed displacement motor (33) driven by the variable flow pump, where the drive is disconnected in dependence of a load and rotation speed of the engine. A fan wheel (34) is driven by the fixed displacement motor and coupled on the displacement motor. A shut-off valve (38) is arranged in a main pipe (32) between the flow pump and the fixed displacement motor, and the fan drive is turned off by an electronic control unit (13). A pressure regulating valve (15) is controlled by the control unit.