Aim: To study the diagnosis and treatment of ependymoma in conus medullaris and cauda equins.

Objective To explore the clinical features and surgical findings of cauda equina and conus medullaris tumors.

A way of calculating the intersecting line of cylinder and cone with the aid of supplementary plane;

Diagraming the characteristic points on the intersection lines between a sphere and a cone by means of the method of anxiliary sphere;

Solution of obliquely intersection-line of cylinder and circular cone;

The Spreading Picture Drawing of the Cylinder and Circular Cone Intersected in the Axial;

The spherical method and auxiliary plane method are usually apply in making up the intersection line, while cylinder and circular cone intersect each other diagonally.

Discussion on machining technology for spherical fiducial surface of tapered roller;

Study of generatrix shape of tapered roller processed with centerless grinding;

Improvement of regulation wheel guiding surface during tapered rollers outer surface grinding;

Taking the cold rolling with the series of 2BD for ISO355 taper ferrule as the example,the method of the pair closed type rolling was used to reduce the spread of the product and to obtain a good surface.