Modeling of undeformed chip in power skiving gear cutting process

Abstract

The method of cutting gear wheel by the Power skiving method is considered and the principle of creating non-deformed chip when cutting external spur gear is analyzed in detail in this paper. The task of this investigation is to develop an adequate model of chip formation and to analyze quantitative estimates of parameters of slices in Power skiving process. In order to solve this problem, complex system of grapho-analytical, mathematical and computer modeling of this process is developed. It takes into account its kinematics and reliably reproduces the regularities of cutting-forming processes. The grapho-analytical method developed by I. E. Hrytsai for worm tooth milling is used to model the parameters of the sections. The continuous movement of cutting and forming is presented in the form of successive discrete movements of the contour of the tooth, and its linear and angular positions relative to the processed gear wheel are easily described mathematically. This greatly simplifies the model and geometric constructions using existing CAD systems, unlike other known methods. In each position of the tooth, its contour in the front surface is combined with the contours of the teeth, which performed cutting in the previous positions both along the axial feed and on the helical line. The main condition for the accurate determination of the parameters of the cuts is the establishment of the shape and dimensions of the surface, which is formed in the process of steady cutting in each cavity of the gear wheel between the treated surfaces of the teeth and the raw surface of the workpiece for 1 revolution of the cutter. To investigate the parameters of the slices, the schematic arrangement of the gear wheel and the cutter is depicted and the process is divided into discrete states. The results of modeling according to the above mentioned parameters are given in the form of graphic dependencies: chip cross-sectional area, thickness depending on different axial feeds of the cutter and for different modules of the gear wheel. The dependence of the change in the geometric characteristics of the undeformed chip on the position of the cutter is obtained. In further research, it is possible to establish a number of other physical quantities and their interdependence during gear cutting using the Power skiving method.