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:
Apr. 30, 2002
Filed:
Nov. 12, 1999
Robin Francis Dorulla, Santa Cruz, CA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
An apparatus and method are provided for sealing and electrically coupling an outer surface of a shaft to an inner surface of a hub disposed about the shaft. The invention is particularly useful for spindle motors used in disc drives . In one embodiment, a seal having a pair of annular pole pieces , coupled to opposite poles of a magnet is positioned between the shaft and the hub . A nonmagnetic, electrically conductive ring electrically couples the pole pieces to one another and to the hub . In one version, the electrically conductive ring includes an annular disk with tabs projecting from the exterior radius. The disk abuts one pole piece and the tabs are folded over to electrically couple to the other . An electrically conductive ferrofluid is magnetically held between the pole pieces , and the shaft to form a pair of axially separated seals , and to establish parallel electrical pathways.