Examination of Hydraulic Suspension Bushing Design Features Using Frequency Domain Models

Abstract

Hydraulic bushings or mounts are commonly used in automotive suspension and powertrain systems to improve vehicle vibration and structure-borne noise features while influencing ride and handling properties. This article aims to analytically examine certain features of hydraulic suspension bushing designs using frequency domain models. First, a linear time-invariant model of a hydraulic bushing with an inertia track is used to examine the dynamic stiffness (magnitude and loss angle) performance up to about 60 Hz with a given excitation amplitude. Second, the effect of inertia track parameters on dynamic stiffness is examined, and the key differences between fluid-filled suspension bushing and hydraulic engine mount are investigated by comparing the fluid chamber compliance ratios. Finally, the frequency dependence of inertia track parameters is analyzed with a quasi-linear model and the measurements of a laboratory prototype device.