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:
May. 25, 1993
Filed:
Sep. 03, 1991
Hiroyuki Yonei, Hikone, JP;
Nippon Densan Corporation, Kyoto, JP;
Abstract
A magnetic disk drive device has a spindle motor for rotatingly driving magnetic disks in a predetermined direction, and a clamp member for mounting the disks on the spindle motor. The spindle motor has a hub rotatably supported through bearings and having a portion for mounting the magnetic disks, a rotor magnet carried by the hub, a stator disposed to oppose the rotor magnet, and magnetic fluid seal arrangement for preventing scattering of lubricant from the bearing means. The magnetic disk drive device further has a magnetic shield on the radially outer side of the magnetic fluid seal arrangement. One of the bearings rotatably supporting the hub may be charged with a lubricant having a comparatively low viscosity, while the other bearing may be charged with a lubricant having a comparatively high viscosity.