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:
Mar. 12, 2002
Filed:
Sep. 02, 1999
Magnetic disk apparatus, including spindle motor having air flow passage in hub for pressure balance
Applicant:
Inventors:
Katsutoshi Nii, Hitachi, JP;
Masaru Muranishi, Odawara, JP;
Kenji Tomida, Odawara, JP;
Kouki Uefune, Odawara, JP;
Shozo Saegusa, Ibaraki-ken, JP;
Yuuichi Yanagase, Ibaraki-ken, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 1/702 ; H02K 7/00 ; H02K 5/167 ;
U.S. Cl.
CPC ...
G11B 1/702 ; H02K 7/00 ; H02K 5/167 ;
Abstract
In a magnetic disk apparatus, the spindle motor is provided with a hole that penetrates the hub in the axial direction thereof. The hole permits fluid pressure on the outside and inside of the hub to become balanced, reducing the axial fluid force caused by the rotation of the spindle motor. The apparatus further includes a bearing provided with a groove for dynamic pressure generation and a magnetic lubrication fluid which, in combination with a permanent magnet, prevents oil leakage and scattering.