Research on the Noise Reduction Method of High Speed Gear Pump Using Inducer to Eliminate Inlet Vortex

With the trend of gear pump to high speed and silent development, its low vibration and noise requirements are becoming increasingly strict. The noise generated by flow and pressure fluctuations and cavitation is the main cause of flow induced noise in oil pumps. In this paper, aiming at the noise induced by the vortex at the oil inlet of the high speed external gear pump (up to 4500 r/min), an inducer and jet device for eliminating the vortex at the oil inlet are designed to actively compensate the oil inlet flow of the gear pump under high speed conditions. The flow field simulation model of high-speed gear pump is established by computational fluid dynamics (CFD), and the morphological evolution of the inlet vortex and the mechanism of vortex noise at different speeds before and after vortex elimination are analyzed. The research results indicate that the presence of vortex at the suction port of the high-speed gear pump induces insufficient oil suction, and the collision of fluid micro clusters at the inlet, as well as the friction between micro clusters and the wall surface, promote the generation of fluid noise. Moreover, the jet tube has the best jet angle to eliminate the vortex at the inlet when facing the meshing line of the two teeth. This study provides a theoretical basis for noise reduction and performance optimization of high-speed gear pumps.