Initial position relation of chord of circular milling cutters and workpiece are determined, through adjust position of worktable X,Y direction and degree of Z direction as well as change angle of inclined rotary table C and level rotary table B based on base cone angle δb. When spiral bevel gears are processed, the work-shaft and level rotary table rotate with angular velocity ωt and ωb respectively to satisfy the equation 4 that ensure the strict proportion of the tool shaft and the workpiece movement so as to realize tooth surface spread correctly. Movement of the tool shaft and workpiece are as above mentioned. Meanwhile, Y axis move with angular velocity based on equation 5 to avoid overcut and complete feed drive. Therefore, the relation of three Axes linkage is composed with workshaft. Level rotary table rotation and Y axis motion to realize milling of skew bevel gears.
Figure 1. 3D Model of Machine Tool
Initial position of machine tool is adjusted according to parameter of gear manufactured, including pressure angle αp, pitch angle δ, mean spiral angle β, base cone angle δb, root cone angle δf face cone angleδa, face width b . Finally, NC program is designed to accomplish cutting process of gears.