Patent ID: 6881918
Filing Date: 2005-04-19
Classification: B23H

Abstract:
1. An electric discharge machining apparatus comprising: an tool electrode having a tip end directed toward a work piece a voltage applied between said tool electrode and said work piece generating a discharge; a drive shaft connected with said tool electrode; an electrode driving device having magnetic bearings for moving said drive shaft in three directions, including a Z-axis direction, which is an axial direction of said drive shaft, a Y-axis direction that perpendicularly crosses the Z-axis direction, and an X-axis direction that perpendicularly crosses the Y-axis direction and the Z-axis direction, by supplying electric current to electromagnetic portions of said magnetic bearings to control magnetic attraction thereof; a movable coupling connected with an end of said drive shaft and movable in the three directions; and an electric motor connected with an end of said coupling for driving said drive shaft to rotate through said coupling.