Hydrostatic transmission for excavator - has connection duct with throttle and outlet branch with check valve

摘要

The transmission forms a closed circuit with pump and actuator, and a control for pump volume. It has a regulating piston, charged on both sides by control pressure, and moved against a spring, and against a force on an additional piston, drive derived from the consumer load pressure. The other end face of this piston has a load pressure-holding connection duct. The tube (14,15) contains a throttle (16,17), with an outlet duct (18,19) branching-off it downstream. This contains a check valve (20,21) with shut-off and passage positions, and a pressure source. The path valve 1s spring-loaded in direction of passage flow, and is loaded in shut-off direction by the control pressure acting on the regulating piston (5).