To study the forming principle of circular arc gear shaped by rotary cutter ,get a reliable circular arc gear 3D model to guide the manufacturing processing and simulation calculation, according to the development of the cutter and the gear workpiece, establish a new reference coordinate system, use the basic knowledge of spatial meshing theory and differential geometry, deduced the tooth surface equations of rotating cutter circular arc gear, derived involute tooth profile of the middle section , analyzed the forming principle of rotating cutter circular arc gear, discussed the range of the parameters of the equation, gave the Calculation formulas under given parameters of the gear workpiece rotation angle, got the digital and three-dimensional model of circular arc gear shaped by rotating cutter. It provides a reference for the parameter selection and design of the circular arc gear, and provides the experimental basis for the following simulation and experiment analysis.
