Decrease the vertical trajectory if you have to 如果没办法的话降低垂直轨迹
2.
The directrixes of the in former two transmissions are the loxodrome and the geodesic on the pitch cones , that of the latter is an equal - pitch line along the direction of straight generatrixes in the hyperboloid surface , also is the vertical trajectory of the straight generatrixes 前两种传动形式的准线分别为节锥面上的斜航线与测地线，后者的准线为单叶双曲面上沿直母线方向的等螺距曲线，且为直母线族的正交轨线。
