High-throughput Experimental Method For Fatigue Resistance Degradation Of Engine Main Shaft Bearing Materials

The bearing capacity and life of the aeroengine main shaft bearing are the key factors that affect the overall performance of the aeroengine.The performance of the bearing is not only affected by the design and manufacturing level,but also closely related to the bearing material.As the requirements of aero-engines main shaft bearings are getting higher and higher,new bearing materials and processing techniques are constantly being developed.In general,it takes a long period of time for new materials from research and development to put into use.In this process,a large number of tests are required to obtain relevant data of the material,which provides a reference for the design and use of the bearing.In order to shorten the application cycle of new materials,this paper designs a rolling contact fatigue testing machine,which aims to obtain different types of data including the fatigue resistance of bearing materials through one test and improve the efficiency of data acquisition.This article first analyzes the characterization methods of bearing material properties including fatigue resistance,and determines that the data that the testing machine needs to collect include acoustic emission,vibration,friction torque,temperature,and total revolutions.Based on these data,it can be used to evaluate the fatigue failure process,static deformation and wear of bearing steel and the lubrication ability of lubricating oil.According to the working conditions of high load,high speed and high temperature of the main shaft bearing,the performance parameters of the testing machine is determined,combined with the relevant requirements of the sensor used to complete the data collection of the testing machine,the parts selection and overall structure of the testing machine are completed.design.According to the design results of the testing machine,Analyze whether the testing machine can work normally.First,the elastohydrodynamic lubrication theory is used to analyze the stress distribution near the contact area of the specimen under different working conditions,and the processing requirements for the specimen are determined to ensure that the test piece mainly produces subsurface fatigue cracks related to the material performance itself.Then,use Workbench to conduct mechanical and thermodynamic analysis on the testing machine to ensure that the structure of the testing machine meets the requirements for use,and there will be no structural damage due to vibration and other factors,or during the test,the temperature of each part used in the testing machine exceeds its rated working temperature,which causes the testing machine to fail.The general assembly of the testing machine was completed,and the electrical part of the testing machine was designed to realize the control of test conditions and the collection and storage of test data.The method of removing noise in the signal collected by the acoustic emission sensor is explored,and the identification of different kinds of acoustic emission signals is realized by combining the wavelet packet transform and the gray system theory.Finally,use the testing machine to carry out verification tests to prove that the testing machine can meet the requirements of use.