The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 1990
Filed:
Apr. 26, 1989
Masachi Hosoya, Kanagawa, JP;
Nippon Seiko Kabushiki Kaisha, Tokyo, JP;
Abstract
A magnetic fluid seal device, which comprises a seal member constituting of two ring-shaped pole pieces attached to the poles of a permanent magnet, a rotor disposed with a gap for the seal member in between, and magnetic fluid magnetically kept in the aforementioned gap. The magnetic fluid is magnetically maintained through a groove defined by the inside faces of the two ring pole pieces and the peripheral surface of the ring magnet, and the distance of the groove on one side of the two ring pole pieces keeping the magnetic fluiid is made smaller than the thickness of the ring magnet at a place on its other side not keeping the magnetic fluid, thus ensuring the magnetic fluid to be injected into the two gaps and the device to be effectually sealed by the two-stage closely adjacent fluid seals formed.