Noise due to pressure pulsations in a pressure-balanced sliding vane pump

Abstract

An experimental investigation of noise in a pressure-balanced sliding vane pump was conducted. The test pump for this research was used in an automobile's hydraulic power steering system. As currently designed, a small portion of the manufactured pumps generate excessive noise during operation.

An experimental test stand facility was used to represent a power steering system for analysis of the excessive noise problem with the objective of determining ways to reduce the noise. Through signature analysis techniques, the sliding vane pump noise was related to the pump's pressure pulsations. The pulsations consisted of three types of pressure oscillations: the pressure ripple with a fundamental component at the vane passage frequency together with harmonics; the low-frequency pressure oscillation with a fundamental component at the rotational frequency together with harmonics; and the high-frequency pressure oscillation. The fundamental vane passage frequency and its harmonics dominated the noise signal frequency spectrum. The pump's internal leakage, which was a function of three clearances in the pumping chamber, determined the magnitude of the pressure pulsations. If the pumping chamber components had inadequate clearances, the pump produced excessive pressure pulsations for a given discharge pressure and, consequently, excessive fluid-borne noise generation. Thus, this study indicated increasing the pump's clearances would minimize the pump's noise generation.