Seal device employing magnetic fluid
AssigneeEagle Industry Co., Ltd.
InventorShigeki Honda
Life of this patent
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Abstract
A sealing device employing a magnetic fluid for sealing off a vacuum side and an atmosphere side includes two rolling bearings disposed on both sides of the magnetic fluid seal. The magnetic fluid fills the lubrication part of the rolling bearing disposed toward the vacuum side and a magnet is attached to the outer ring toward the vacuum side of said rolling bearing. A ring-shaped yoke formed from a magnetic material and freely fitting into a rotation shaft is attached to the side of the magnet opposite the outer ring of the rolling bearing.
Claims11
A seal device employing magnetic fluid, the seal device adapted for sealing off a vacuum side and an atmosphere side, and furnished between a housing and a rotating shaft,
- the seal device characterized in being equipped with rolling bearings furnished to the vacuum side and the atmosphere side so as to support said rotating shaft inside said housing;
- a lubricated portion of the rolling bearing is filled with a magnetic fluid, and a magnet being installed on the vacuum side of an outer race;
- and
- on the opposite side of said magnet from the outer race of said rolling bearing, a ring-shaped yoke made of magnetic material being installed in a loose-fitting manner on the rotating shaft;
- said ring shaped yoke being furnished with a protruding portion on the side thereof facing towards said magnet, said protruding portion being furnished in the circumferential direction with a plurality of recessed portions of cylindrical or rectangular shape that open towards said rolling bearing outer race side, and magnets being fitted within said recessed portions.
Dependencies are inferred from the claim text.