Research on Flexibility of Bearing Rings for Multibody Contact Dynamics of Rolling Bearings

The flexibility of bearing rings is very important to calculate the characteristics of rolling bearings in some rolling bearing applications such as planetary gear, rolling mill and aircraft. It may cause significant changes in dynamics characteristics, bearing deflections, contact stresses, and fatigue endurance, especially under heavy applied load, large size bearing, hollowed shaft and nonrigid bearing housing. The purpose in the work presented is to research a new approach and multibody model of bearing rings for MBS of mechanical system with rolling bearings. The flexibility and three-dimensional multibody model of bearing rings have been developed using equivalent rigid elements and curved Timoshenko beam elements. The simulation of the bearing rings vibration response will be presented. In addition to the presented multibody model, the FEM model and analytical model are also used to perform the vibration analyses of the bearing ring. An investigation of the actual static deformation field of the outer ring loaded by 5 balls has been carried out for the radial displacement field using the presented model. The total number of the discrete equivalent rigid elements and CTB elements has an important effect on the predicted frequencies, however the results will be minimal changes when the elements are achieved a certain number. In such situations, the presented approach can provide multibody rings model for contact dynamics of rolling bearings with acceptable accuracy and considerably less computational effort. The calculated radial static deformation is critical to load distribution, life fatigue and dynamics characteristics of rolling bearings. The three-dimensional multibody model of bearing rings developed here and the predicted frequencies agree well with the analytical results and FEM.