Friction And Wear Performance Of Variable-speed Curved Surface Of Cageless Ball Bearings

As a new type of non-standard rolling bearing,cageless ball bearings,with simple structure,high bearing capacity,low friction resistance and light weight,will surely become the basic parts for applications in the fields of drones and aerospace.However,although this type of bearing eliminates the frictional resistance brought by the cage,the contact collision and friction between the rolling elements still affect its working performance.In order to eliminate this problem,the design of the variable speed curved surface on the outer raceway of the bearing enables the rolling elements to be automatically dispersed,but at the same time it also brings the automatic dispersion of the rolling elements due to the wear of the variable speed curved surfaces.For this reason,this paper analyzes the friction and wear performance of cageless ball bearings with variable-speed curved surfaces.Through theoretical analysis,numerical simulation,and experimental verification,a wear-resistant model of variable-speed curved surfaces is established and its wear failure time is predicted.First,based on the discrete motion state of the cageless ball bearing rolling body,the speed of the rolling body rolling over the variable speed curved surface is analyzed,and the speed equation of the rolling body rolling over the variable speed curved surface is established.The contact form and force state of the rolling body and the variable speed curved surface are established.Analyze and establish the contact mechanics model between the rolling body and the variable speed surface;analyze the type of wear between the rolling body and the variable speed surface,and combine the previously solved speed and stress equations to establish a theoretical wear model of the variable speed surface based on the classic Archard model.Secondly,the wear depth in the theoretical wear model is studied,and the discrete wear depth equation for numerical simulation is established based on the finite element method.For the improved 6206 bearing,the non-retaining with elliptical and rounded rectangular variable speed curved surfaces is established.The finite element simulation model of the frame ball bearing,through static and dynamic numerical simulation analysis,determines the stress value of the contact area of the two speed-changing curved surfaces;the determined stress value is brought into the discrete wear depth equation,and the two types of contrast are analyzed.The total wear depth and the number of wear times of different speed-change surfaces.Finally,the data fitting was performed according to the wear depth,and the relationship equations between the wear depth and the wear times of the two speed-change surfaces were established to provide a theoretical basis for the prediction of the failure time of the later speed-change surfaces.In order to verify the correctness of the relationship between the wear depth and the number of times in the wear model of the variable-speed curved surface,a physical prototype of wear-free cage ball bearings was built.Three sets of variable-speed curved surfaces under different wear times were selected for testing.The wear quality and wear depth were measured to compare the theory.The results and test results verify the correctness of the wear model.Finally,an example of the modified 6206 non-cage ball bearing variable speed curved surface is used to predict the wear model of the variable speed curved surface to determine the failure time of the variable speed curved surface without affecting the discrete rolling elements.In this paper,by analyzing the friction and wear performance of the variable speed curved surface,the influence of the degree of wear of the variable speed curved surface on the rolling element dispersion is determined.This technology is of great significance for the application of ball bearings with variable speed curved surfaces without cages.