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:
Sep. 03, 1991
Filed:
Jul. 09, 1990
Applicant:
Inventor:
Akira Yamamura, Tokyo, JP;
Assignee:
Nippon Ferrofluidics Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
310 905 ;
Abstract
This invention discloses a magnetic bearing device having a control coil which supports a rotor in a vertical direction and a current controller which increases control current according to an increase in the clearance between the control coil and the rotor. The current controller includes a gain controller which controls the control current with a larger gain when clearance between the control coil and the rotor is less than a certain distance, and with a smaller gain when clearance between the control coil and the rotor is more than that distance.