Research On Load Bearing Characteristics And Dynamic Response Of Roller Bearing-rotor System

Rolling bearing is widely used in aviation,aerospace and other rotating machinery because of the characteristics of simple structure,good bearing performance and low friction loss.In this dissertation,the cylindrical roller bearing-rotor system is taken as the object,the load distribution and friction torque characteristics of the cylindrical roller bearing are analyzed.The influence of the bearing parameters on its dynamic characteristics and the dynamic response of the rotor system are studies,which provides support for dynamic design of bearing-rotor system.The main contents of the dissertation are as follows:1.The mechanical relationship and dynamic equation of each component of cylindrical roller bearing are established.Based on the Gupta's cylindrical bearing model,the interaction among roller,outer ring and cage of cylindrical roller bearing are analyzed,and the coordinate transformation is used to obtain the relationship between the interaction force and torque of each component.The multi-degrees-of-freedom dynamic equations of each component of the bearing are established.2.The load distribution and friction torque characteristics of cylindrical roller bearings are studied.By the calculation of load deformation coefficient and radial integral,based on Hertz line contact theory,the internal load of bearing under different radial load and clearance is solved by the iterative method,and the corresponding load characteristics are analyzed.The mechanical model of the interaction of various components of cylindrical roller is established,and the characteristics of the bearing friction torque are studied.3.The dynamic model of cylindrical roller bearing is established.Based on the established dynamic model of cylindrical roller bearing,the nonlinear dynamic equations of the bearing are constructed.The Runge Kutta method is used to solve the dynamic equation.By analyzing the time series,center trajectory and Poincare mapping of the bearing under different structural parameters,the influence of radial clearance,the number of rollers and the change of damping coefficient on the dynamic response of the bearing is studied.4.The dynamic model of cylindrical roller bearing-rotor system is constructed.The radial and tangential motions of rollers,and the inner ring motion are considered into the proposed model.The nonlinear dynamic equations of the system are derived by the Lagrange equation.The Runge Kutta method is used to solve the dynamic equations of the system.The nonlinear dynamic response characteristics of the system are obtained by analyzing the time series and center trajectory of the system under different rotation speeds.This dissertation can provide a reference for the dynamic design of cylindrical roller bearing and bearing rotor system.