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:
Oct. 15, 1991
Filed:
Jan. 22, 1990
Teruo Umehara, Hanyu, JP;
Seiki Takedomi, Fukaya, JP;
Kuninori Imai, Kanagawa, JP;
Takeji Shiokawa, Fuchu, JP;
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
A linear motor comprising a center yoke made of a ferromagnetic material; outer yokes made of a ferromagnetic material, having permanent magnets, each having magnetic poles on the inner and outer surfaces thereof and fixed to the inner surface of the outer yokes, and disposed outside the center yoke with both ends thereof being magnetically coupled; and a movable member having coils wound on the outer circumference thereof and axially movably disposed in a gap between the center yoke and the outer yokes, in which recesses are provided on the opposing surfaces of the center yoke and the movable member, and a static-pressure gas bearing is formed by providing an air intake vent connecting to these recesses.