Nonlinear Dynamic Analysis of Elastic Rotor with Disk on Cantilevered End Supported on Angular Contact Ball Bearings

Abstract

The mathematical model of rotor nonlinear oscillations on angular contact ball-bearings has been developed. The disk is fixed on the console end of the shaft. The shaft deflection and the elastic deformation of the bearings have the same order. The free oscillations have been analyzed by nonlinear normal modes. The modes and backbone curves of rotor nonlinear oscillations have been calculated. Oscillations are excited by the simultaneous action of the rotor unbalance and vibration of supports. The frequency response, orbits and Poincare maps have been constructed on the mode when rotating speed of the rotor is in the frequency range of supports vibration. The analysis o f nonlinear dynamics of the rotor has shown that besides the main resonance at low frequencies there are superresonant oscillations. The unstable modes saddle-node bifurcations leading to beats are observed.