| 摘要 |
PURPOSE:To lower dust generation and reduce driving forces in a semiconductor manufacturing device and the like so as to miniaturize the device by retaining a magnetic fluid in a clearance between magnetic poles by means of magnetic forces, and providing both the fixed side and moving side poles with magnetic forces so as to retain the magnetic fluid to each magnetic pole when the poles are separated. CONSTITUTION:During sealing, a driving shaft is rotated by an external driving force and the door main body 8 is pressed against a stopper 10 and airtightness is maintained by a magnetic fluid 11 retained at the protruding portion of a magnetic pole. When an opening is needed, as during insertion, etc., a driving shaft 9 is reversed clockwise through 90 deg. by the external driving force and the door 8 is reversed and opened. Then the magnetic fluid 11 is retained by a magnetic force at the protruding portion of the magnetic pole and so will not scatter but reverts to its original state when the door is closed again, thereby maintaining airtightness. Deformation and contact of a solid do not occur during this cycle, neither abrasion nor dust generation occur, and there is no need for pressure connection so little driving force is required. |
