Hydraulic unit, has valve connecting flow-reversible pump with connection line of another flow-reversible pump before switching another valve in load drive state, where hydraulic fluid is not conveyed to piston chamber in load drive state

摘要

The hydraulic unit (10) has a valve (64) i.e. directional valve, connecting an annular chamber (18) with a hydraulic fluid tank (34) based on pressure in a piston chamber (16). The valve connects a flow-reversible pump (32) with a connection line (62) of another flow-reversible pump (30) before switching another valve (60) i.e. pressure sequence valve, in a load drive state, where hydraulic fluid is not conveyed to the piston chamber by the former pump and the latter pump in the load drive state. The pumps are designed as fixed displacement pumps or internal gear pumps. An independent claim is also included for a method for operating a hydraulic unit.