Research on asymmetrical supporting rotor system with radial clearance

Abstract

In this paper, the dynamic model of the rotor with asymmetric support structure of ball bearing and cylindrical roller bearing is established based on the rotor support structure of a gas turbine. The influence of the radial clearance of the rolling bearing on the nonlinear dynamics of this type of rotor system is studied. The fourth-order Runge-Kutta method with variable step is adopted to analysis the dynamic characteristics of the system by using the bifurcation diagram, phase diagram, Poincaré section diagram and FFT diagram of the system. The result shows that when the radial clearance is small, the system has a long period of stability. The system will gradually exhibit nonlinear behaviors such as period 2 motion and chaotic motion with the increase of radial clearance. The research can help to reveal the nonlinear dynamic behaviors of the rotor system with radial clearance of the rolling bearing and provide some theoretical basis for the theoretical design and fault diagnosis of complex rotor system.