具有公共对称面的两个二次回转面的相贯线

The Intersecting Curves in Two Quadratic Rotary Surfaces Which Possessing Public Symmetry Plane

本文论证了常见的两个二次回转面轴线相交和平等时，其相贯线在公共对称面（投影面）的投影分别为双曲线和抛物线．只有在特殊情况下是直线，椭圆和圆，并举例说明在计算机上绘图的方法．

This paper demonstrated when two qyadrqtic rotary surfaces are intersecting or parallel, the projection of their intersecting curves in public symmetry plane is hyperbola or parabola respectively. in specialy it is rectilinear ellipse or circle.