rackn.行李架；（放衣物、碗碟等的）架子；拷问台；折磨；（比赛开始前固定球位置的）三角框vt.使痛苦；把...放在架子上；累计取得rackern.行拷刑者；使人痛苦者

1. In this paper, the equation of the projection of hob helicoid has also been deduced and the projection is compared with the basic rack nomal profile.
   文中还求出了滚刀螺旋面的投影方程式，并与媒介齿条法面齿廓方程做了比较。