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. 08, 2003
Filed:
Sep. 29, 2000
Thilo Rehm, Villingen-Schwenningen, DE;
Jörg Hoffmann, Mettlach, DE;
Precision Motors Deutsche Minebea GmbH, Villingen-Schwenningen, DE;
Abstract
A spindle-drive motor for hard drives having a baseplate, a shaft and one or more bearings for rotational mounting of a rotationally driven rotor, with at least one magnetic fluid seal arranged between the stationary part and the rotating part of the spindle-drive motor. The seal is formed of an upper and a lower yoke lamination and a magnet disk arranged between the yoke laminations, where a concentric chamber is formed so that it is open toward the inside on one side to hold a magnetically conducting fluid. A flux concentrating lamination extends into this chamber. In one embodiment of this invention, the flux concentrating lamination is in direct or indirect contact with one end face of the inner bearing ring of the bearing, while the outer part of the magnetic fluid seal is in direct or indirect contact with the end face of the outer bearing ring of the bearing. In another embodiment, the flux concentrating lamination on the inside is in direct or indirect contact with a radial reference shoulder of the shaft.