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. 21, 1993
Filed:
Jun. 26, 1992
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A control apparatus of a magnetic bearing controls electromagnets so that both a displacement deviation of a center of gravity of a rotary shaft and an angle of twist around the center of gravity of the rotary shaft become 0, thereby supporting the rotary shaft in space by the magnetic force of the electromagnets. The apparatus includes .theta..sub.X and .theta..sub.Y control devices for controlling angles .theta..sub.X and .theta..sub.Y of twist of the two degrees of freedom of a rotational motion orthogonal to each other around the center of gravity and perpendicular to an axial direction of the rotary shaft, a cross feedback being produced so that both a feedback signal of the rotary angle .theta..sub.X and a feedback signal of the rotary angle .theta..sub.Y are respectively fed back as cross feedback signals to the .theta..sub.Y and .theta..sub.X control devices. A rotational speed detecting device for detecting a rotational number of the rotary shaft. Each of the control devices includes a break frequency and gain value varying device which has a break frequency not larger than a reply frequency of the entire control apparatus with respect to the cross feedback signal, the varying device varying the break frequency of the lowpass filter in inverse proportion to the rotational speed of the rotary shaft, and varying a gain value of the cross feedback signal in proportion to the detected rotational speed of the rotary shaft.