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:
Feb. 21, 1989
Filed:
Dec. 21, 1987
Helmut Habermann, Vernon, FR;
Societe Anonyme: Societe De Mecanique Magnetique, Saint-Marcel, FR;
Abstract
The electromagnetic device comprises at least one compensation ring placed in the vicinity of the fluid bearing and mounted relative to the rotor by means of an active radial magnetic bearing whose electromagnet windings are powered as a function firstly of the signals delivered by a position detector for detecting the position of the compensation ring relative to the rotor, and secondly of the signals delivered by at least two vibration detectors disposed on the casing of the machine and having nonparallel sensitivity axes which are perpendicular to the axis of the rotor. The signals delivered by the vibration detectors are applied to a high-gain narrow-band selective feedback circuit whose central frequency is synchronized with a reference frequency fo. The compensation ring is of relatively small mass and serves to exert a rotary compensation force on the rotor via the radial magnetic bearing, which force is equal to the centrifugal force due to the out-of-balance mass of the rotor but which is 180.degree. out of phase relative thereto, thereby reducing casing vibration while expending little energy.