Research On Prediction Method Of Spur Gear Tooth Surface Wear

Gears are important components that transmit motion and power through the interaction of meshing tooth surfaces.Among various types of mechanical transmission,cylindrical gears account for about 48%,and are widely used in mechanical equipment for motion transmission,speed change and reversing.Among the various failure modes of gears,wear failure accounts for about 60% to 80%.The Archard’s wear formula is most widely used in gear wear prediction at present.Through the Archard wear formula,the wear prediction can be realized,and then the gear design can be guided.However,it is difficult to accurately determine the wear coefficient in the formula,which affects the accuracy of the wear prediction.To solve this problem,an accurate measurement method of the tooth profile deviation in the FZG gear test considering the installation error was proposed.Based on the method,iterative filtering was used to obtain the accurate tooth profile wear amount,and the wear coefficient was calculated point by point along the tooth profile direction.Finally,the micro-pitting safety factor of each point was calculated for the prediction of tooth profile wear.The main research contents of the thesis are as follows:(1)A method for compensating the installation error of the tooth profile in-situ measuring device based on a profilometer was proposed.In the FZG gear test,the influence of the installation error of the tooth profile in-situ measuring device on the measurement results was theoretically analyzed,and the gear measurement using a profilometer was designed to verify the theoretical derivation.Finally,an installation error compensation method by projecting the measurement data to the plane perpendicular to the gear datum axis was proposed.The calculation of the tooth profile deviation curve measured at different stages in the FZG gear test was realized.(2)An iterative filtering algorithm was proposed to obtain the upper contour line of tooth profile deviation curve for the accurate assessment of gear tooth wear.The selection method of filter type,cutoff wavelength and stop condition in iterative filtering was studied.Based on the obtained upper contour lines of the tooth profile deviation curves in different stages,the wear amount of each point along the tooth profile in each test stage was obtained.(3)The tooth profile wear prediction method based on Archard’s formula combined with the micro-pitting safety factor of each point on the tooth profile was studied.The wear coefficient determining method of each point on the tooth profile based on the wear amount and the Archard’s wear formula was studied.According to the international standard ISO/TS 6336,parameters such as the specific oil film thickness,allowable oil film thickness and safety factor at each stage on the tooth profile surface were calculated point by point,and the boundary line of the safety factor for wear was determined.The prediction of gear tooth wear during FZG geat tests was realized.The thesis systematically focuses on the accurate measurement and evaluation method of tooth profile wear in FZG gear tests.On this basis,the wear coefficient in Archard’s formula was determined,and the wear prediction of cylindrical gears under lubricated conditions was realized by combining with the micro-pitting safety factor,which can benefit gear tribological design.