As it is impossible to machine the helicoid gear surface with large module and a few teeth by gear generating, a four-axis milling was developed in this paper.

• 针对大模数少齿数螺旋齿轮的加工特点,结合渐开线和摆线的性质,利用微分几何工具计算出该类曲面的法矢,作为选取球头铣刀半径的依据。