A method for forming an elliptical involutes gear in CAD

A method of forming an elliptical involutes gear is proposed based on Visual LISP implanting AutoCAD in this paper. First, a geometric model is established according to a pinion cutting principle of the involutes profile and geometric location relationship between pinion cutter and pitch curve of elliptical gear. It makes pinion cutter do pure rolling on a pitch curve of elliptical gear. Then the arc length of cutter on the pitch curve is equal to the length of cutter rotating around its rotation center in order to guarantee the generating grinding teeth between the pinion cutter and the blank in processing. Finally, teeth profile of elliptical involutes gear is formed utilizing graphics movement simulation in AutoCAD by Visual LISP programming.