Analysis Of Load Properties Of Cylindrical Roller Bearing And Research On Shafting Accuracy

The transmission shaft with rolling bearings is widely used in machinery and equipment of high precision.The rotation accuracy of shafting often determines the whole precision of mechanical system.Therefore,it is very important to study the accuracy of the precision shaft system.The cylindrical roller bearings is the object,considering the influence of geometric error and lubrication,a quasi-dynamic model of five degrees of freedom of bearings is established,bearing load performance is analyzed,establish the rotating precision shafting model,completes the rotating precision shafting impact analysis,and according to the requirements of rotary precision of shafting,complete layout optimization of bearing.The main contents are as follows:(1)The structural features of roller bearings,Hertz line contact theory and raceway control theory are briefly introduced.Fourier series is used to represent the geometric errors of raceways.The application of Elastohy-drodynamic Lubrication in high speed rotating bearings is briefly described.Considering the bearing element geometric error,lubrication,dynamic load,and the influence on the bearing capacity of inclined inner ring bearings,and uses the slice method to calculate roller and raceway contact force,a cylindrical roller bearing with five degrees of freedom quasi-dynamic model is established,using the Newton-Raphson algorithm to solve the problem,analyzes the bearing performance of the bearing.The finite element model of bearing is established by using ANSYS,and the calculation results are compared with the theory.(2)Based on the quasi-dynamic model of five degrees of freedom of cylindrical roller bearings,a rotational accuracy analysis model of two bearings flexible shafting is established,and the bearing load distribution and the internal load distribution of both ends are calculated.By using the finite element beam element equalizing shafting and stiffness superposition theory,the bearing stiffness matrix is introduced into the whole system stiffness matrix,matrix analysis and calculation,obtain rotation accuracy of an arbitrary point on the shaft.The accuracy of optical axis and hollow shaft of beam element is verified by Kissoft software.(3)Considering the flexibility of bearing inner ring,a calculation model of flexible ring bearing is established,the effects of roller diameter error,raceway error,radial clearance,number of rollers,preload,speed and load on the rotation accuracy of shafts under the rigid and flexible inner race conditions are analyzed and compared.The results show that when there is an adjacent error roller in the rigid condition,there is nothing to do with the runout and the maximum displacement.The error roller should be stagger as far as possible under the flexible condition,which is beneficial to improve the rotary accuracy.With the increase of inner ring error order,when the number of roller meets the specific relation of outer ring error order,it is beneficial to rotation accuracy.When the error level is higher,increasing the number of rollers can effectively improve the rotation accuracy.Under specific preload,the maximum displacement varies approximately linear with the radial force.Under the flexible condition,the rotation speed has little influence on the rotation accuracy.The axial runout in flexible condition is more sensitive than that of rigid condition,and the radial runout is more sensitive than the flexible condition in rigid condition.(4)Finally,based on the above research basis,bearing life or rotary precision of shafting for goal,program and optimize shafting bearing arrangement,it provides reference for the design of shafting precision.