Charging effect of port-plate centrifugal pump in electric motor-pump under variable speed

Electric motor-pump is a novel integrated hydraulic power unit which is mainly composed of an electric motor,aport-plate centrifugal pump and a main pump(a high-pressure vane pump).The portplate centrifugal pump is set in the front of oil suction cavity of the main pump to improve the pressure of the inlet of the main pump by utilizing the charging effect and ensure sufficient oil suction of the main pump.The internal flow field model of the port-plate centrifugal pump in the electric motor-pump is set up,the flow field under variable speed is conducted and the comparative analysis on port-plate centrifugal pump charging effect is simulated.The results shows that the total pressure on the outlet port of portplate centrifugal pump(the inlet port of the main pump)enhances continually with the increase of rotational speed and its maximum valve characterizes the oil compensation effect.The maximum value of the total pressure increases rapidly and linearly when the rotational speed is higher than 1 000r/min and it relatively increases by 15.5times when the rotational speed reached 2 000r/min.