Determination of stiffness parameters of toothed gears of automobiles and tractors

Abstract

In simulation of functioning processes of technical objects with toothed gears, in many cases there is a need to consider the elastic properties of gear engagements. This is especially important for simulation of high-frequency vibrations. The aim of the paper is the development of method determining the coefficients of flexural and contact stiffness of gear engagement required to build a mathematical model of the functioning process of toothed gear and evaluate its impact on the technical object performance in general. The novelty consists in the development of a model of substitution of tooth for variable cross section beam allowing to describe adequately the physical processes of deformation of gear engagement, as well as in the obtaining on its basis the calculating formulas for determination of flexural deformation and stiffness coefficient of gear engagement. To determine the contact stiffness of teeth, new developments in the field of contact deformations of interacting mechanical objects are used. The calculations are carried out and diagrams of dependence of coefficients of flexural and contact stiffness on the gear module and load are constructed. It is shown that the flexural stiffness coefficient depends only on the module and the width of the ring gear, but does not depend on the load, while the contact stiffness is sensitive also to the load, which is caused by volume change of strain sensitive material of tooth. The proposed formulas allow to determine with acceptable accuracy for practical purposes the parameters of the elastic properties of spur and helical gears with external and internal engagement.