The forming principle of Niemann worm wheel hob is described, the curved face equation of Niemann worm is deduced, and the normal profile of the worm wheel hob is calculated.

• 论述了尼曼蜗轮滚刀的成形原理,推导了尼曼蜗杆曲面方程,计算了蜗轮滚刀的法向齿形。