| 摘要 |
A method and apparatus for eroding inner and outer walls of work pieces, such as cylinders and cones, by electrical discharge between the work piece and an electrode are described wherein an electrode-holder is mounted for variable orbital movement on a hollow support fixed on a cylinder axially movable by fluid pressure with respect to a piston therein, along an axis perpendicular to the plane of the orbital movement. A normally fixed piston rod carries the piston, and a shaft extends through the piston rod from the interior of the support to means, providing for coarse and fine adjustment, fixing the shaft to the rod. A rotor in the support is rotatable on the shaft and has an inclined track with which an inclined track on a cam unit is in sliding engagement. The cam unit is rotated on the electrode-holder by power means supported thereby and the cam unit rotates on an axis parallel to the shaft and which orbits about the shaft at a radius depending on the relative position of the two cam tracks which orbit with the electrode-holder. Alteration of the orbit radius or eccentricity is effected either by adjustment of the shaft in the piston rod or by axial movement of the cylinder which is limited in each direction by stops. In the event of excessive pressure arising in the cylinder the piston rod can yield axially against resilient restraint. |
