Nonlinear Resonances and Self-Excited Oscillations of a Rotor due to Radial Clearance and Impact in Bearings (Experiments and Numerical Simulations)

摘要

Oscillations in a rotor system with a radial clearance between the outer ring and the casing are investigated by experiments and numerical simulations. The mathematical model includes collision in the clearance. The following phenomena are found: ( 1 )Various kinds of nonlinear resonance occur. ( 2 )Self-excited oscillation of a forward whirling mode occurs in a wide range above the major critical speed. ( 3 )Entrainment phenomena occur in the resonance ranges of nonlinear forced oscillations. In order to obtain a guideline to rotor design, the influence of bearing damping, rotor unbalance and static lateral force on the occurrence of the nonlinear resonances and self-excited oscillations are investigated.