Safety and stability of two kinds of ship rotor bearing system under rolling condition

Rolling condition, the bearing load is changed with time, which is bound to affect the safety and stability analysis results of the rotor-bearing system. Only through the steady state analysis that is difficult to guarantee the security and reliability of the support bearing. In this paper, using a rotor-bearing system dynamic characteristics analysis software DLAP (dynamic lubrication analysis program) developed by the lubrication theory and Bearing Research Institute of Xi’an Jiao Tong University, solution of the Reynolds equation and the temperature viscosity equation. The key operating parameters of the elliptic and offset bearing such as the minimum oil film thickness, maximum oil film pressure, temperature rise, power dissipation and flow rate are obtained. At the same time, the axis orbit and the oil film pressure of the two kinds of bearings are compared and analyzed under rolling condition. In addition, based on the assumption of piecewise linearization of bearing stiffness and damping, the rotor-bearing model with different rolling angles was established. Coupled solution of the two kinds of rotor-bearing system dynamics model was presented. By means of eigenvalue and eigenvector, unbalance response analysis, stability analysis and transient dynamic analysis, the stability and safety of the rotor-bearing system are studied in detail. Finally, the dynamics characteristics of rotor system supported by ellipse and offset bearings under rolling conditions were obtained.