Study of Elastic Axis Decoupling in Engine and Gearbox Mounting on the Vehicle Chassis

The elastic axis decoupling to offset the elastic center of the automotive engine mounting system towards the center of gravity of the power-train is studied. General procedure of diagonalization of stiffness matrix which is a factor of the principle stiffness, coupled stiffness, position and inclination of engine mounts is analysed. Maintaining symmetry of the mounting system to ensure functional characteristics the elastic axis decoupling can be achieved by simplification to few factors of relative stiffness ratios, relative position ratios and multiplication factors. The effect of CG shift from the plane of symmetry on the coupling of the modes of vibration can be seen. The inevitability of perfect elastic axis decoupling can be assessed to achieve the optimal partial elastic axis decoupling required to the designers need.