Examination of Hydraulic Suspension Bushing Design Features Using Frequency Domain Models

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.