The structures and the engagement principle and the performances on the spherical envelope worm indexing cam mechanism are discussed.

• 介绍了其结构形式，推导了分度盘上球面齿廓方程、啮合方程、球面包络蜗杆分度凸轮廓面方程，最后指出了这种新型球面包络蜗杆分度凸轮机构优良的结构特性