Rubbing Dynamics of Dual‐Disk Rotor System Supported by Oil Film Bearing

As the clearance between the rotor and the casing gradually becomes smaller, the probability of collision and friction increases greatly, the rubbing dynamics of the dual disk‐shaft‐bearing system is studied in this paper. Considering the gyro effect of rotor, a dynamic model of the rotor system under nonlinear oil film force is established; the matrices of Timoshenko beam and coupled rigid disk elements are obtained and the rotor support is described by the analytical formula of Capone nonlinear oil film force. Taking the deformation and energy dissipation into account during the rubbing, the rubbing stiffness is characterized by using nonlinear Hertz contact theory. It is innovative to study the mechanism of the rub‐impact dynamics for the rotor system considering the nonlinear oil film force of sliding bearing. The equation of motion for the rotor system is derived to investigate the effect of the rotating speed, the eccentricity, the rubbing clearance, and stiffness on the nonlinear dynamic responses. The results indicate that the rotational speed, the eccentricity, rubbing clearance, and stiffness have significant effect on the nonlinear dynamic behaviors of the dual‐disk rotor with the sliding bearings; the system presents complex dynamic behaviors such as period, multiperiod, quasiperiod, jumping, and paroxysmal chaos. From the perspective of rotor stable operation, there are optimal ranges of the speed, eccentricity, and rubbing parameter, and these parameters should be considered comprehensively to avoid the rotor working in nonlinear motion states such as chaos and quasiperiod. The research work has important guiding significance for the selection of rotor balance accuracy level, design of static gap, and structure optimization.