In this paper a new grinding method, using small cylindrical facegrindingwheel to grind straight outline hourglass worm, is put forward and the mathematical model is set up.
本文提出了用小圆柱面砂轮磨削直廓环面蜗杆的新方法，建立了数学模型。
2
SHOULDER: Defect found on rib or outer diameter; a raised edge on rib face caused by grindingwheel; raised surface at either end of outer diameter raceway.
挡肩：外径或挡肩上发现的缺陷；挡肩上由于磨床砂轮所造成的突起；在外径滚道两端的突起。
3
Cylinders, straight cups, and flaring cups are used for surface grinding with the end face of the wheel.