Hydrostatic drive for car auxiliaries - has parallel hydromotor circuits for fan and generator with electronic control of pressurised fluid supply from pump

摘要

A hydrostatic drive in a car for both the cooling fan of a heat exchanger and the generator uses a load pressure-controlled pump driven by the engine. Each circuit uses a hydromotor supplied with pressurised fluid by the pump, the two circuits being in parallel. The generator is run at constant speed. There are solenoid-operated proportional throttle valves (43) for the fluid to the hydromotors fed by an electronic control unit (60), which receives signals from a temperature sensor at the fan and a speed sensor at the generator. The control unit has a pre-defined program of operation. ADVANTAGE - Load on the pump is constantly matched to the requirements of the fan and the generator to maintain max. efficiency at all times.