A novel machining method using an internal skiving cutter with multiple inserts to manufacture ZC cylindrical worm

The cylindrical worm is usually manufactured by forming methods, such as whirling or milling; however, the aforementioned methods are restricted to machining time and control machining profile with stock. Therefore, this paper introduces a novel machining process designed for ZC concave worms, simultaneously enhancing machining efficiency and profile control ability. Accordingly, a skiving cutter with multiple inserts on an internal helical gear tooth is proposed. A curve-fitting model of the generating rack is first illustrated to generate the ZC worm flanks when considering grinding stock conveniently. The position of the cutting edge is then analyzed via the geometry of an internal barrel worm to ensure non-interference during the cutting process. In addition, the insert body is generated based on the helicoid motion of the cutting edge. Subsequently, it also presents a machining process to grind the insert body. Furthermore, the skiving process employing multiple inserts on a multi-axis CNC machine is presented. Finally, the meshing and boundary points of the cutting trajectory are concurrently defined during the skiving process. The numerical results demonstrate the high precision and absence of overcutting in skived worm profiles.