design of electro-hydraulic control for the pump discharge pressure control

摘要

electro-hydraulic control system (22), the hydraulic pump (30) for driving the fan (17) By using the solenoid (25) connected to the control valve 3 position spool (24) of (23) to urge, to manage the speed of the hydraulic fan (17). At the first position, the spool (24) releases the pressure on the de-stroke actuator of the pump (30) (34), in response to the speed of the engine (11) driving the pump (30), on-stroke It increases the output pressure to the actuator (32). At the second position, the spool (24) is to isolate the de-stroke actuator (34), fixes the pressure output of the pump (30). In the third position, the spool (24), the de-stroke actuator (34) is connected to the output of the pump, resulting in a reduction in the pressure output of the pump (30). Solenoids connected to the spool (24) (25) sets the output pressure spool (24) is the second position.