Stepless variable pressure pump based on proportional control valves

Abstract

The constant pressure variable pumps are useful in hydraulic systems of aircraft and machines. The variable pump pressures can bring the advantage of energy saving in the hydraulic system. A new variable pressure pump strategy is proposed here to obtain the continuous pressure's change, based on the proportional control valves. The main idea is using proportional valves as pilot valves for the axial piston pump, and the pressure of pump can reach the pressure requirement by setting valves' input pressure. The pressure sensor at the discharge port of pump is not needed, which is a highlight for this scheme. The commercial software AMESim is used to model the system of pump. The case of constant pressure is simulated, and the robustness of this hydraulic system is researched. Both step variable pressure and stepless variable pressure are investigated, as well as a case of the flight actuator with variable pump, indicating that the effectiveness of the pump is demonstrated. The stepless variable pressure axial piston pump can be used in the hydraulic system of high efficiency and different pressure levels.