Structural optimization and verification to suction runner of high-speed external gear pump

To improve the volume efficiency of high-power external gear pump under high-speed operation, the structure of suction flow runner was analyzed, optimized and verified. Firstly, the simulation model based on Pumplinx verified by experiment was utilized to unveil the flow field characteristics in suction runner of the conventional external gear pump (CEGP), followed by analysis of the key factors influencing CEGP's absorption efficiency. Subsequently, leveraging the analysis results, optimization was performed on suction runner to obtain the novel external gear pump (NEGP). Ultimately, the performance of the NEGP was validated. The results indicate that the volume efficiency of CEGP at 3000 rpm is 81.87%, exhibiting a 11.81% reduction compared to the maximum value. The centrifugal force exerted by the gears expels the oil, which interacts with the incoming flow into the tooth cavity to form localized vortices, thereby increasing absorption resistance and constituting the primary cause of volume efficiency reduction. Compared with CEGP, NEGP exhibits an increase in volume efficiency by 11.24% at 3000 rpm, demonstrating superior oil suction performance at high speeds.