Studies on friction and wear properties of surface produced by ultrasonic vibration-assisted milling

The grinding of elliptical gears on a computer numerical control (CNC) gear grinder with conical wheel is studied according to the mesh theory of elliptical gears. Two machining methods form the machine structure and movement, namely a mobile grinding wheel type and a fixed grinding wheel type. Mathematical models of the movement relation for the elliptical gear grinding process are built up. Since the teeth of the elliptical gears are different from each other, their generating length is also different. Based on the analysis of generating and indexing movement, a universal generating length formula of each tooth is proposed. Basic machining parameters of each tooth, for these two types of machines, are computed using a practical example. The dynamic simulation of generating track is given. The research results show that the grinding of elliptical gears with a CNC conical wheel gear grinder is feasible.