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:
Feb. 20, 1996
Filed:
Jan. 25, 1994
Satosi Uno, Hitachi, JP;
Sueo Akashi, Hitachi, JP;
Katsutoshi Nii, Hitachi, JP;
Kazuhiko Kawaike, Katsuta, JP;
Hiroo Hiroyama, Hitachi, JP;
Kosho Ishizaki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A motor provided with a magnetic fluid bearing device for suppressing vibration and irregular rotation as well as preventing the magnetic fluid from being scattered from a bearing portion and the inside of the motor. The motor includes a rotor having a polygon mirror mounted thereon, a stator unit having driving coils, a rotor position detector and a rotor revolution detector attached thereto, a magnetic fluid bearing unit having a magnetic seal and a dynamic pressure seal attached thereto and a magnetic bearing. A triple seal structure for magnetic fluid which includes a first fluid seal constituted by the seals of the bearing unit, a second fluid seal constituted by a magnet of the rotor and a third fluid seal constituted by a magnet of the seal magnet is provided in the motor.