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:
Aug. 27, 1996
Filed:
Aug. 07, 1995
Zine-Eddine Boutaghou, Rochester, MN (US);
Luke A Cossette, Rochester, MN (US);
Richard W Luoma, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A magnetic fluid seal is provided by mounting an annular, axially polarized magnet mounted on the device base member and an annular ring pole piece with an inner diameter that cooperates with an outer diameter surface of the hub assembly to form a fluid gap that is radially outward and within the axial extent of the spindle bearings. The secondary gap of the seal assembly is within the bearing assembly sealed volume while the principal sealing gap is within the hub assembly to confine any debris or aerosols resulting from high rotational velocity or shock to be contained in proximity to the flux fields that can recapture any magnetic material. The assembly also inherently presents an effective conductive path to provide enhanced grounding of the rotating assembly through the magnetic fluid in the second gap which is not subject to impairment caused by bonding materials. The seal assembly design also provides for self loading of the magnetic fluid without permitting escape of smeared liquid beyond the region of the seal assembly.