A CAD System of Geometrical Design for Internal Gear Pair and Its Application to the Design of Three-Ring Gear Reducers

In this paper, a new numerical method is proposed to draw the closed diagrams of modification coefficients, and the structure of a CAD software is demonstrated,which is based on the calculation method for internal gears cut with gear shaper. The system consists of the modules for ploting the closed diagrams of modification coefficients, for choosing the modification coefficients, and for calculating values of constraint functions and gear′s geometrical parameters. Also, a module is intently attached to the system, which can be used in the series design of involutes planetary gear drive with small teeth difference. This CAD system is validated in the design process of a new product series of three-ring gear reducers.