Linkage model and manufacturing process of shaping non-circular gears

• Propose a 3-linkage model of shaping non-circular gears
• Discuss the shaping process of non-circular gears
• Implement the shaping process in a widely used CNC gear shaping machine

Current research of non-circular gear processing mainly focuses on gear hobbing. However, this method has many limitations including being unable to process internal gears or non-circular external gears with a concave pitch curve and is likely to undercut when processing non-circular gears of greater curvature with a smaller number of teeth. Gear shaping, in contrast, is a method that is able to overcome the limitations of gear hobbing. Relevant studies on gear shaping have focused on the theoretical bases rather than the concrete processes and tools. Through the combination of shaping theory and practice, this paper aimed to derive a linkage model for shaping non-circular gears, and to refine the feeding strategy, and develop a cutter retraction and cutter setting method. Finally, with a pair of 3-order sinusoidal-gear-ratio non-circular gears, this paper demonstrated the entire process in a CNC gear-shaping machine, thus proving the accuracy of the mathematical model and providing a valid reference for shaping non-circular gears.