Analysis Of The Contact Force Between Rotor And Retainer Bearing After Rotor Drop

The motion phase diagram under various initial rotational (θ,θ) is obtained using the established rotor dynamic equations for different processes after rotor drop. And the influences of various friction coefficients and clearances on motion trajectories are discussed. Based on the Hertz contact theory, more accurate nonlinear contact force model between rotor and retainer bearing after rotor drop is established. The principle to measure the contact force is proposed. And then according to the measure principle, the measure rig is designed. The whole measure process is divided into calibration and measurement. Considering the nonlinear effects of the measure rig, the measure rig is firstly calibrated using impact force hammer under various impact forces. Then the contact forces are calculated using the acceleration responses of support ring after rotor drop.The rotor drop experiments for various initial rotational speeds are carried out. The acceleration responses of the support ring, rotor trajectories and drop duration time are detailed analyzed. The experimental results show that the vibrations and impacts become larger and drop duration time lasts longer with the increase of initial rotational speed, and then whirling motion is more likely to happen. The results also show that the maximum of vibration impact appears less than0.1second after rotor drop, but not appears at the first collision. The measurement and calculation process of contact force between rotor and retainer bearing after rotor drop are detailedly given for the initial rotational speed at4500r/min. Both the first contact force and the maximum restoring force are obtained. The first contact force is then used to recognize the equivalent mass me and equivalent stiffness ke in the established nonlinear force model. Finally, the relevant design criterias of retainer bearing are put forward after summarizing the conclusions in this paper as well as some other scholars’research works.