Study on the Spring-Piston External Mesh Gear Pump with Low Flow Fluctuation

The cycle function of input flow rate was obtained by Fourier transformation of the instantaneous input flow rate of external mesh gear pump. The model of hydraulic system consisting of gear pump, spring, piston and load was established, the differential functions of the model were established too. The influence of dynamic compensating characteristics in the system caused by both pistons with different area and stiffness of spring was analyzed with MATLAB software and the change of fluctuating flow in the same system was obtained. The simulation result shows that the flow fluctuation of external mesh gear pump could be reduced by using the spring-piston system.