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:
Aug. 23, 2005
Filed:
Jun. 07, 2002
Keigo Kusaka, Akashi, JP;
Takafumi Asada, Hirakata, JP;
Keigo Kusaka, Akashi, JP;
Takafumi Asada, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A rotatable hub in which a supporting shaft having hydrodynamic pressure generating grooves is inserted comprises an annular thrust bearing plate in its lower portion and annular permanent magnets in its upper portion. The thrust bearing plate is inserted between the lower end face of the supporting shaft and a thrust flange fixed to the supporting shaft, maintaining the respective clearances D and E. The permanent magnets on the hub are confronting in such a manner that an upward and downward repulsive forces are generated between permanent magnets mounted on the supporting shaft, respectively maintaining the clearances B and C. Since the clearances B and C are greater than the clearances D and E, the permanent magnets will not mutually contact even when the hub is caused to move upward or downward by an external force during rotation and the thrust bearing plate contacts with the lower end face of the supporting shaft or the thrust flange.