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. 18, 2006
Filed:
Nov. 19, 2004
Shingo Tsuda, Kanagawa, JP;
Mutsuro Ohta, Kanagawa, JP;
Hiroki Kitahori, Kanagawa, JP;
Kazutaka Okasaka, Kanagawa, JP;
Shingo Tsuda, Kanagawa, JP;
Mutsuro Ohta, Kanagawa, JP;
Hiroki Kitahori, Kanagawa, JP;
Kazutaka Okasaka, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the present invention effectively control, by a simple structure, floating of a rotor of a fluid dynamic bearing motor mounted in a hard disk drive. In one embodiment, a base is formed of a magnetic material. The attractive force caused by the magnetic force acts between a bottom of the base and a magnet unit that is constituted of a rotor magnet and a back yoke. This makes it possible to attract a rotor to the base against the buoyant force produced by a thrust bearing, and thereby to effectively control the rotation of the rotor. On the bottom of the base, at a position facing the magnet unit, a convex part protruding from the inner surface of the base is formed in a ring-shape. Adjusting the height, or the width, of the convex part makes it possible to control the magnetic back pressure applied to the rotor.