A reconfigurated rack-tool for the generation of gears

Abstract

The cutting processes with tools that generate “through-winding straight-involute teeth-gears”, tools associated with couples of centrodes-in-rolling (such as the rack-tool), are characterized by a fairly complicated cutting scheme, due to the specific shape of the tools and, at the same time, due to the rolling process of the axodes associated with the tool and the blank. The present solutions are not accorded well enough to the process and lead to significant variations in the detached chip area value regarding the machined wheel teeth number. It is accepted that the main cutting force size depends on the size of the area of the cutting layer (the geometrical area of the once detached chip by the assembly of operative edges of this kind of tools). The geometrical modeling of the generation process proves this and it could be considered a criterion for the reconfiguration of the cutting tool. In this work, there is defined a criterion so as to describe the cutting scheme, and based on this criterion we can compare the variation laws for the chip area size when generating the modeling of the cylindrical straight teethed gears. We propose a modeling of the cutting schemes in order to get new constructive forms of the cutting tools that will lead to cutting schemes adaptable to the number of teeth of the processed gear with the purpose of diminishing the teething cutting force. Also, there is presented a constructive solution for a rack-tool with reconfigurable structure with the purpose of according the teething process with the processed gear number of teeth.