Internal Load Sequence And Life Analysis Of Rolling Bearing

Rolling bearing is used to reduce friction and bear load in the mechanical systems,the life of the rolling bearing will affect the life of the entire mechanical system.When being moderately loaded and well lubricated,the main failure forms of rolling bearing is the fatigue spalling of surface material.The influence of the motion state of bearing on the life was seldom considered in the existing life model.In this thesis,the contact state and stress on the inner ring,the outer ring and the rolling elements were calculated.The load sequence of the contact points and fatigue life of the bearing was analyzed for the cases of different operation conditions.Part 1 described the significance of bearings with respect to the calculation of the load sequence and life,and reviewed the research progress of rolling bearing fatigue failure,fatigue life model and dynamic research.Part 2 proposed the calculation formula of load distribution for deep groove ball bearing c-onsidering ball revolution and compared it with the original results.Considering the influence of clearance and centrifugal force,corresponding Matlab programs were developed to calculate the load distributions.The contact stress and load sequences of points on the inner raceway,outer raceway and ball were analyzed.The fatigue life of the bearing is calculated based on the L-P theory and the life model is improved according to the difference of stress cycles of the contact points under different operation conditions.The bearing life under 4 different operating conditions were comparatively studied.Part 3 studied the load distribution of cylindrical roller bearing.Taking the center point on the contact line of the contact area as the research object,the load sequence of the roller,inner and outer raceway are calculated.Matlab Programs were developed to compute the fatigue life of inner raceway,outer raceway,roller and the bearing reveal the influences the motion state has on the fatigue life.The effects of different clearances and centrifugal forces was also considered.Part 4 calculated the load distribution of angular contact ball bearing under different radial and axial loads.Deformation compatibility and the force equilibrium equations were established to compare the contact angle before and after bearing loads.The influence of radial force,axial force on bearing life is analyzed.Part 5 summarized the major work in this thesis and proposed other crucial issues that require future research endeavor.