Centrifugal effects on cavitation in the cylinder chambers for high-speed axial piston pumps

摘要

Raising rotational speed is an effective way to improve the power density of axial piston pumps. However, cavitation tends to happen in the pump's cylinder chambers at high rotational speeds, which limits the speed increase for a greater power density. The speed-dependent centrifugal effect of fluid is considered as one of important factors influencing this cavitation occurrence. Therefore, this paper presents an extensive analysis of centrifugal effects on the cylinder cavitation. First, an analytical model is developed to analyze the centrifugal effect on the pressure distribution in the cylinder chambers, followed by criteria for the rotational speed and inlet pressure. Second, a computational fluid dynamics model is established to predict the cylinder pressure and cavitation. Both analytical and simulation results indicate that the centrifugal effect creates a radially inhomogeneous pressure in the cylinder chambers. Specifically, the centrifugal effect inhibits the cylinder cavitation near the outside wall of the cylinder bores but aggravates the cavitation near the inside wall of the cylinder bores. From the viewpoint of cylinder cavitation, it is necessary to decrease the volumetric displacement for high-speed axial piston pumps.