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:
Jun. 29, 1993
Filed:
Mar. 05, 1991
Takashi Kataoka, Kanagawa, JP;
Yuji Shirao, Kanagawa, JP;
Daisuke Konno, Kanagawa, JP;
Yoshio Sato, Kanagawa, JP;
Yoichi Kanemitsu, Kanagawa, JP;
Hideo Tsuboi, Kanagawa, JP;
Shunichi Aiyoshizawa, Tokyo, JP;
Kazuyuki Kasahara, Kanagawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A spindle motor has a rotor supported by a stator through a thrust bearing and a radial bearing. At least the thrust bearing is a hydrodynamic bearing. The spindle motor is provided with a device for adjusting the thrust laod that is applied to the thrust bearing. The load adjusting device has an electromagnet that is provided on the stator and a permanent magnet that is provided on the rotor in opposing relation to the electromagnet. Either the repelling force or the attraction force, which acts between the electromagnet and the permanent magnet, is controlled by changing the current supplied to the electromagnet.