Research And Development Of Fretting Wear Tester For Automobile Wheel Bearings

In the working process of automobile hub bearings,due to the uncertainty of external excitation,the form of friction existing in the bearing is more complicated.Fretting wear occurs in the contact between the roller and the raceway.Due to the uneven distribution of the positive pressure in the contact area,the metal deformation state of the contact surface is different,and the local friction is changed,thereby oxidizing and destroying the contact surface.Studying the phenomenon of fretting wear of automobile wheel bearings and exploring the development method of its testing machine is helpful to the development of the theory of fretting wear of automobile wheel bearings and is of great significance to the practical application of automobile wheel bearing engineering.This article summarizes the basic theory of fretting tribology and its application in the fretting wear of automobile wheel bearings.Based on the general theory of elastic contact,the shear stress distribution of the fretting contact of automobile wheel bearings is studied.From general to special,the wear mechanism model of fretting wear of automobile wheel bearings is established.According to the theoretical basis,in accordance with the test standards of the hub bearing,combined with the actual test requirements of the project,the test requirements and the design criteria of the test machine are determined.Based on this guide,the overall frame of the test machine is determined and the main components of the test machine are determined.Using CAE software and finite element analysis software,the structure model of the testing machine was designed and established.The installation and debugging of the testing machine have been completed.The maintenance and maintenance plan of the mechanical system has been formulated.According to the design standards,after the experimental machine was built,a series of simulation tests were carried out in strict accordance with the test requirements to verify the effectiveness of the experimental machine.A sample of the hub bearing for the test was selected,and the material properties of the sample were analyzed.Through the analysis of the characteristics of the sample material,the sample was preliminarily processed,and the loading method of each parameter and various test conditions in the test process were determined.Through the collection of test data and curve fitting,the fretting mechanism of automobile wheel bearings is studied through data analysis;the metal state under fretting wear of automobile wheel bearings is analyzed by metallography,and the various stages of fretting wear are observed under a microscope The surface state of the hub bearing summarizes the forming state of the hub bearing under fretting wear.