Patent attributes
A hydraulic pressure supply unit has two exits that are alternately pressurized, a reversible pumping unit including at least two pumps, reversible electric motor that drives all pumps jointly, if necessary with mutually de-locking check valves before the exits, and a supply for hydraulic medium. One pump is a low-pressure pump and one pump is a high-pressure pump, and the pressurized exits of both pumps are placed against the same exit of the pressure supply unit. Both exits of the high-pressure pump can be separated from the low-pressure pump via check valves, and each pump is connected to the supply for hydraulic medium via its own shuttle valve. Both exits of low-pressure pump can be connected to a tank via pressure on-off valves, and the control connections of pressure on-off valves are connected to the exits of the high-pressure pump in such a way that the control connection of that pressure on-off valve on the currently pressurized side is applied with pressure by the currently pressurized exit of the high-pressure pump.
