The Bifurcation Analysis of the Rotor-Bearing System Supported by Oil-Film Journal Bearing and Thrust Bearing

The rotor-bearing system supported by oil-film journal bearing and thrust bearing is proposed in this paper. The pressure distribution and the dynamics of a rigid rotor are studied. Due to the nonlinearity factors of oil-film force, the analysis of the rotor-bearing system supported by journal bearing and thrust bearing are investigated on the basis of the assumptions of incompressible lubricant, rigid rotor, the neglect of the side leakage effect in thrust bearing together with long journal bearing approximation. Theoretical bifurcation analysis of rotor center motion is carried out by means of numerical investigation, the procedure here being numerical integration. The displacement in the horizontal, vertical and axial directions charactering the theoretical model of the system are considered with non-dimensional speed. Numerical results show that, the stability of the system is varied with the non-dimensional speed ratio and the initial values. It is concluded that the rotor center trajectory has undesirable vibrations. Understanding the bifurcation behavior of these parameters provides theoretical and practical ideas for controlling rotor-bearing systems and optimizing their operation.