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. 10, 1999
Filed:
Apr. 19, 1996
Ebara Corporation, Nikkiso Co., Ltd., , JP;
Seiko Seiki Co., Ltd., , JP;
Abstract
An electromagnetic rotating machine driven by an electromagnetic action between a stator and a rotor has drive windings fitted to the stator for generating a rotating magnetic field for rotatably driving the rotor, position control windings fitted to the stator for generating a magnetic field having a different number of poles than that of the drive windings, a magnetic force generation circuit for generating a magnetic force to act on the rotor by supplying the position control windings with an electric current effective to unbalance the magnetic field on the stator side, a circuit for detecting an induced voltage or current generated in the one or more position control windings in response to radial displacement of the rotor and the rotating magnetic field generated by the drive windings, a circuit for detecting radial displacement of the rotor based on the induced voltage or current and the magnitude and speed of the rotating magnetic field, and a position control circuit for controlling the radial position of the rotor by changing the magnetic force generated by the magnetic force generation circuit in accordance with the detected radial displacement of the rotor.