在万工显上测螺旋槽滚刀齿距轴向移动时,光学分度头需旋转θ角,所测得的是滚刀法向齿距在轴向的投影齿距,实测投影齿距减去理论投影齿距的差值即为齿距误差。θ值可由下例四个公式任意一个中求得: In the million workers were measured on the helix hob pitch axial displacement, the optical indexing head to be rotated θ angle, the measured hob pitch pitch in the axial projection pitch, the measured projection pitch minus To the theoretical projection pitch difference is the pitch error. The value of θ can be found in any of the following four formulas: