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:
Oct. 04, 1983
Filed:
Dec. 16, 1982
Kuldip Raj, Merrimack, NH (US);
Raoul Casciari, Bedford, NH (US);
Ferrofluidics Corporation, Nashua, NH (US);
Abstract
A single-pole-piece ferrofluid exclusion seal apparatus and exclusion seal system which comprises a single, annular pole piece to surround a shaft element to be sealed, and an annular permanent magnet secured to one surface of the pole piece in a magnetic-flux relationship, the single pole piece having a one end which extends into a close, noncontacting relationship with the surface of the shaft element to be sealed, to define a small radial gap between the surface of the shaft element and the one end of the pole piece, and a ferrofluid positioned within the radial gap, to provide a ferrofluid seal with the shaft element, the ferrofluid comprising a high magnetization-type ferrofluid, with the magnetic flux path of the single-pole-piece ferrofluid seal extending between the shaft, the ferrofluid in the radial gap, the single pole piece in the permanent magnet and the air gap between the magnet and the shaft.