An approach to an NVH investigation of vehicle hydraulic pumps

Abstract

This work presents a method for analyzing the noise and vibration problems caused by hydraulic pumps in vehicles. This methodology is based on experimental research and coherent analysis of observed systems. Experimental investigations are conducted in order to determine dominant excitation of hydraulic systems. Vibrations and sound pressure levels of pumps were investigated with respect to the determination of the influences on pump NVH. Measurements were performed in different operating conditions. Pressure of oil in the hydraulic system was varied. A new method of assessment and determination of dominant NVH pump excitation is presented. Experimental results are used as input and output data for coherent analysis. Performed analyses of coherent functions showed dependence of pump velocity and sound pressure level especially in the low frequency region to 4.5 kHz. Results showed that the number of measuring channels can be reduced, especially in high frequency domain. Results can be used in experimental design.