The effect of support parameters on the force transmissibility of a flexible rotor

Rotating machinery support design with the aim of reducing the force transmitted to the foundation has significant importance regarding the various applications of these machineries. In this paper presents a rapid approximate method for calculating the optimum support flexibility and damping of flexible rotors to minimize force transmissibility in the vicinity of the rotor first critical speed. First, the governing equations for the Jeffcott rotor model mounted on flexible supports are derived and the optimal parameters for the supports have been analytically achieved. Next with consideration of the complexity and tedious of the analytic equations, a numerical algorithm for determination of the optimal support design parameters is introduced which may be applied to any rotor model regardless of the model complexity and number of degrees of freedom. The simulation results show the effect of optimal parameters on the considerable reduction of the force transmitted to the foundation. The method has the advantage of being quickly and easily applied and can reduce analysis time by eliminating a time consuming search for the approximate optimum damping using more exact methods.