Analysis Of Dynamic Characteristics Of Elastic Composite Cylindrical Roller Bearing

The elastic composite cylindrical roller bearing is an original new type of rolling bearing.By innovating the structure of the bearing assembly,the bearing achieves the purpose that improves the bearing condition of the rolling element and that improves the bearing capacity and fatigue life of the bearing.In the former,the inventor of the elastic composite cylindrical roller bearing and its scientific research team have studied the composition principle,structural design,manufacturing process,contact characteristics and preliminary engineering applications of the bearing,and have achieved a series of results.In order to comprehensively study the basic theory of the bearing,under the support of the National Natural Science Foundation of China and the Natural Science Foundation of Hunan Province,this paper has conducted in-depth research on the dynamic characteristics of elastic composite cylindrical roller bearings.The main research contents include:First,the modal characteristics of elastic composite cylindrical roller bearings and their rolling elements based on filling degree were analyzed.The effects of the structural parameters of solid cylindrical roller bearings,elastic composite cylindrical roller bearings and the corresponding rolling elements of two bearings on the natural frequencies and modes of various modes were studied.The results showed that as the degree of filling increases,the natural frequencies of the various stages of the bearings and rolling elements decreased sequentially,and that the vibration mode of each bearing mainly showed the bending and torsional deformation of the inner ring.Second,the dynamic response of solid cylindrical rolling element and elastic composite cylindrical rolling element under impact load were studied.According to the modal analysis results of each rolling element,the sampling frequency was determined.The effect of external load and filling degree on the damping of the rolling element structure was discussed by using the characteristics of free displacement of the rolling element node after unloading.The results showed: due to the existence of structural damping,in the loading phase and the unloading phase,the displacement of each rolling element node oscillated around theequilibrium position and gradually approached a stable value.The equilibrium position of the rolling element in the loading phase changed with the filling degree of the rolling element;the damping ratio of the rolling element can be changed by the structural design,and the damping ratio decreased as the filling degree increases.Third,the harmonic response of elastic composite cylindrical roller bearings were analyzed.The modal superposition method was used to establish the solid cylindrical roller bearing and the finite element model of the elastic composite cylindrical roller bearing with the filling degree of 40%,50% and 65%.The displacement and stress response of the same joint of each bearing component under the harmonic excitation load were compared and analyzed.The results showed that the peak excitation frequencies of the displacement and stress of the cage,the rolling element and the inner ring node were close to the natural frequencies of the fifth-order mode and the sixth-order mode of each bearing.Fourth,based on the explicit dynamics theory,the dynamic equivalent stress variation characteristics,motion law and vibration characteristics of assemblies of solid cylindrical roller bearings and elastic composite cylindrical roller bearings with different structural parameters under certain working conditions are compared and analyzed.The results showed: the structural design of the elastic composite cylindrical roller bearing improved the dynamic stress condition between the bearing components;and the reasonable selection of the filling degree of the elastic composite cylindrical roller bearing rolling element can achieve the vibration damping effect.Fifth,the vibration displacement test of the elastic composite cylindrical roller bearings were completed.The vibration displacement test of the elastic composite cylindrical roller bearing was carried out by using the rolling bearing comprehensive test-bed.The relative error of the radial vibration test data and the finite element calculation result of the bearing was within 11%,which verified the correctness of the finite element model.The conclusion of the research on the dynamic characteristics of elastic composite cylindrical roller bearings in this paper can enrich thebasic theory of the bearing,and can provide a theoretical reference for the structural optimization design,fault diagnosis and engineering application of the bearing.