Working mechanisms and dynamic performances for a hydraulically damped bushing with an inertia track

Abstract

Hydraulically damped bushings (HDBs), due to their superior elasticity and damping, are frequently employed in vehicle suspension systems to lower levels of noise, vibration, and harshness (NVH) of a vehicle. Although HDBs have similar configurations with well-known hydraulic engine mounts (HEMs), the working mechanism and dynamic performances of HDBs are still not clearly revealed. In this paper, efforts have been made to explain potential differences in performances of HEMs and HDBs with one inertia track. Comparisons and investigations are carried out in terms of geometry structures, dynamic modeling, and multiple characteristic parameters including equivalent mass and damping amplification ratios, as well as flow and pressure responses of inertia track fluid. Furthermore, a unified analytical model of a bush-type HEM, which is able to control the motion and vibration of an engine with compact powertrain space, is established to investigate dynamic characteristics of either HEM or HDB, so as to optimize NVH performances of a vehicle in the design stage.