Characteristics of Fluidborne Noise Generated by Fluid Power Pump : 2nd Report, Pressure Pulsation in Balanced Vane Pump

Abstract

This paper presents a discharge pulsating pressure (fluidborne noise) generated by a balanced vane pump. It is pointed out first that the pressure pulsation in vane pump includes three types of pressure oscillations, namely, the well known pressure ripple with a fundamental component at vane frequency together with harmonics, the low-frequency pressure oscillation with a fundamental component at rotational frequency of rotor together with harmonics, and the transient high-frequency pressure oscillation occurring with a period of vane frequency. In regard to the pressure ripple, it is pointed out that the experimental values can be explained well, up to about 8th harmonic of it, by the calculated values based on the present mathematical models for flow ripple considering fluid compressibility and pump source impedance. It can be said also that the above-mentioned low-frequency pressure oscillation is caused by the fluctuation in pump leakage flow depending on the rotational position of the pump, and that the transient high-frequency pressure oscillation is caused by the resonance of oil column in the pump discharge chamber including a port adapter.