Nonlinear hydraulic engine mount

Hydraulic engine mounts experience both small and large engine motions. When small engine vibration motions are present, it is desirable to have low mount dynamic stiffness in order to reduce engine transmitted vibration to the cabin. But when large shock motions are present, it is desirable to have high mount dynamic stiffness to prevent and control excessive engine motions. With rubber to metal (RTM) bonded engine mounts, dual stiffness characteristics are very common. When engine motions are small, the stiffness will be low and when large engine motions are present, the rubber engine mounts stiffen up. With conventional hydraulic engine mounts, decouplers are normally used to provide dual stiffness characteristics. But decouplers have tendencies to get stuck in their cage bounds or sink to the bottom of the cage bound. Here in this paper, a new hydraulic engine mount design is presented that is amplitude sensitive without a need for a decoupler. Here in this paper, the new engine mount design is presented, its mathematical models are derived, and simulation results are presented using MATLAB.