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. 14, 1990
Filed:
Feb. 16, 1990
Ikumi Satoh, Iruma, JP;
Jun Nakano, Iruma, JP;
Riichiroh Harada, Iruma, JP;
Tatsuhiko Koba, Iruma, JP;
Yuichi Fujita, Ichikawa, JP;
Kazumi Shima, Sakura, JP;
Kabushiki Kaisha Yaskawa Denki Seisakusho, Fukuoka, JP;
Toyo Engineering Corporation, Tokyo, JP;
Abstract
A motor-operated valve is constructed such that a stator is provided outside of a nonmagnetic tubular member allowing flow of a fluid, with stator coils wound around a plurality of magnetic poles, and a plurality of permanent magnets are secured to an operating surface of each magnetic pole. The permanent magnets are magnetized into a number of pole-pairs arranged at a constant pitch. A rotor is rotatably supported inside of the tubular member. A number of induction teeth are formed along the circumference of the rotor at a pitch equal to the pitch of the pole-pairs of the permanent magnets, and the total number of the induction teeth is so selected that it is different from the total number of the pole-pairs of the permenant magnets by an amount equal to an even number. A mechanism including a rotation-preventing means is also provided in the rotor for converting the rotating movement of the rotor into a linear movement of a valve member.