Research On Design And Contact Characteristics Of Aviation Crowned Involute Spline

Misalignment is the key factor leading to eccentric load,stress concentration,wear and fatigue of aviation spline.Spline modification provides a feasible way to improve the load sharing meshing as well as avoid stress concentration under the condition of spline misalignment.In view of the imperfection of the design method of crowned spline and the uncertainty of the modification range,this paper puts forward a method to determine the crowned size range of the crowned spline by using the allowable stress of the spline tooth surface and the interference of the internal and external splines.Taking the central transmission rod spline of an aeroengine as an example,the design of crowned spline is carried out.The contact simulation of spline is carried out to evaluate the contact characteristics of ordinary spline and crowned spline in ideal alignment and misalignment state from the aspects of Mises stress,contact slip and tooth surface pressure distribution.On this basis,the influence of backlash on the contact characteristics of spline is studied.Finally,the pressure distribution test platform of the spline tooth surface is designed,which effectively combines the design,simulation and experiment,and verifies each other.It is concluded that the contact performance of the self-designed crowned spline is better than that of the ordinary involute spline under the misaligned condition.The specific research includes:(1)For the design of the crowned spline,based on the geometric relationship of the key teeth meshing under the condition of spline misalignment,the design formula of the crowned spline is derived,and the correction factor K is introduced to simplify the design formula of the crowned spline.Finally,four kinds of parameters of the crowned spline are designed through the specific aviation spline parameters.(2)In the aspect of simulation calculation,the finite element model of spline contact is established in the case of ideal alignment and angular misalignment.The contact characteristics of four kinds of crowned spline and ordinary involute spline are co MPared one by one,and the conclusion that the contact characteristics of crowned spline are better than ordinary spline under misalignment condition is obtained.(3)In the aspect of experimental research,aiming at the problems of small clearance and large contact pressure of spline tooth surface,this paper designs and builds a spline tooth surface pressure test bench by using Japanese pressure measuring film.The equivalent finite element model is established by commercial finite element software.Through the co MParison between the experimental data and the simulation data,the reliability of the previous simulation calculation is effectively verified,which provides a reference for the pressure test of spline tooth surface in engineering practice.