Abstract: Hydraulic engine mount (HEM) has the best performance among the passive engine mounts and is the first option for design of mounts for vibration isolation of powerplant. Based on the third generation of HEM, which has three types of hydraulic mechanisms such as the inertia track, the decoupler and the disturbing plate, some changes of the inertia track are made or the hydraulic mechanisms are organized again, then the influences of the hydraulic mechanisms, the length of the inertia track and the local loss of fluid flow at the entrance of the iner-tia track to the dynamic characteristics of HEM are experimen-tally studied, the working principle of the three types of hydrau-lic mechanisms and the relationship between the three types of HEMs are revealed clearly. These results will be helpful for the selection of the design scheme of HEM, and the lumped pa-rameters model of HEM and its analytical conclusions are proved to be correct. Based on the fact that the experimental results and the analytical results are matched well and according to the lines’ shape of the dynamics stiffness in phase as a func-tion of the excited frequency and amplitudes, a new parameter identification method for the bulk stiffness of the upper chamber and the effective pump area of the main rubber is presented, which is clear in principle and the identified results are reliable because it is not sensitive to the error of measurement. The new method is time and cost saving because the test can be done on a conventional elastomer test system and there is no need to design a new hydraulic measurement setup.

Key words: Parameter identification, Dynamic characteristics, Hydraulic engine mount, Powerplant, Vibration isolation