Calculation methods for the vibration control design of a powertrain mounting system.

A model for a powertrain mounting system (PMS) consisting of hydraulic engine mounts (HEM) for vibration control of the powertrain is presented. Calculation methods for determining the dynamic displacements of a powertrain center of gravity (c. g. ) and the dynamic reaction forces of each mount in a PMS under ground and engine shake excitation are deveIoped in this paper. Also a general strategy for determining the peak frequency of the loss angle and the amplitude of the loss angle of an HEM is proposed. The amplitude versus frequency responses of a powertrain c. g. and reaction forces of mounts are estimated for a generic PMS with four rubber mounts or two rubber mounts and two HEMs with the developed formulae. The calculated results demonstrate that the amplitudes of a powertrain c. g. in bounce mode and roll mode (around engine crankshaft) and reaction forces in each mounts of a PMS can be reduced greatly by using HEMs, thus reducing vibrations of the car body. The methods developed in the paper can be used for optimizing dynamic characteristics of mounts according to the design criteria of powertrain vibration control. [ABSTRACT FROM AUTHOR]