Research Of Nonlinear Vibration Characteristic Of Rotor-bearing System Based On Energy Method

As the most important part of aircraft engine,the dynamic characteristics of the rotor-bearing have the huge impacts on the working performance and reliability of the whole body.Moreover,the nonlinear factors caused by the rolling bearing will directly affect the vibration performance of the rotor-bearing system,and a series phenomenon that linear theory fails to explain will appear.In order to reveal the movement mechanism and ensure the system to be safe and efficient,the research of nonlinear rotor-bearing system is done in this paper.At first,the bearing is simplified to quality-spring system,and the nonlinear dynamic models of cylindrical rolling bearing and angular contact ball bearing are deduced by the method of Lagrange energy respectively.Then the dynamic models of rotor-bearing system are established through combining with the dynamic models of bearings.With the system supported by SKF NU1013 and 7013CD as example,and using Runge-Kutta to do the numerical analysis.The effects of radial clearance of bearings and speed of rotor on the nonlinear vibration characteristics of the rotor-bearing system are analyzed with the bifurcation,phase diagram,Poincare diagram.And the method to establish the range of radial clearance of bearings and the speed of rotor is also illustrated.Finally,the test system is designed to measure the vibration parameters of rotor-bearing system and some experiment studies are done based on the test system.By comparing the experimental results with the theoretical calculation results,the nonlinear dynamic models established in this paper are verified.