Research On Fretting Wear Of Floating Involute Spline Coupling

Transmission gear box as a core part of modern light rail and subway,the involute spline couplings play a vital role in the transmission gear box.The floating spline couplings need to transmit large alternating torque and other directional loads,which resulted in serious fretting wear of the spline couplings,the failure of the spline connection and the reliability of the entire transmission system.Therefore,it is of great significance to expand the fretting wear study of the floating involute spline to improve the fretting wear resistance of the spline.Firstly,through the in-depth analysis of the fretting wear mechanism of the involute spline,the internal and external factors affecting the wear of the spline pair are studied,and the formula of the wear of the spline is deduced,secondly,the finite element method is used to analyze the different loads of the involute spline couplings,finally,the fretting test workpiece was designed for the fretting wear experiment.The main research contents of this paper are as follows:(1)The finite element analysis of the load distribution of the involute spline is carried out,the distribution of the contact pressure on the tooth surface and the position of the maximum stress on the tooth surface are obtained.When the pure torque is input,the load of each tooth face is almost the same,and the maximum contact stress occurs on the edge of the torque input shaft,with the increase of torque,the contact area extends to the edge of the spline tooth along the tooth direction,and the contact stress also increases,and the load distribution remains unchanged;when the loading mode is acted by radial load and torque simultaneously,the load on the tooth surface is no longer uniformly distributed,the ends of the spline coupling bear large load pressure,and the load pressure on the middle face is lower than the two sides.(2)The finite element analysis of the involute spline coupling model of helical gear is carried out,and the load distribution law under the combined action of torque,radial force,tangential force and overturning moment is obtained.The load on the tooth surface of the helical gear is no longer uniformly distributed,but a load mutation is taken,the stress on the middle tooth surface is greater than that of the two sides.The more serious the sudden change of load is due to the increase of torque,which is due to the additional overturning moment passing through the contact surface of the spline pair,resulting in the load of some teeth biased to the other side,so as to balance the force of the whole spline tooth.(3)According to the parameters of spline finite element model,several groups of spline test pieces were processed for fretting wear experiments,thus the suspension fretting wear test beach is built,so as to study the fretting wear morphology of spline surfaces and the wear effects of various factors on spline pairs.The number of cycles has a greater influence on the spline coupling wear,with the increase of the cycle period,the amount of tooth surface wear increase;the deeper the carburized layer,the better the anti-fretting performance of the spline coupling;when the input torque is increased,the load of the tooth face is larger and the wear of the tooth surface is more serious.