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. 18, 2012
Filed:
Jun. 01, 2010
Fumitoshi Yamashita, Miyota-machi, JP;
Shinsaku Nishimura, Miyota-machi, JP;
Noboru Menjo, Miyota-machi, JP;
Fumitoshi Yamashita, Miyota-machi, JP;
Shinsaku Nishimura, Miyota-machi, JP;
Noboru Menjo, Miyota-machi, JP;
Minebea Co., Ltd., Nagano, JP;
Abstract
A micro rotor is disclosed and includes a plurality of circular or annular plate-shaped thick film magnets which each include an isotropic magnet with a thickness thaving an in-plane remanence Mr of 0.95 T or more and a coercivity HcJ of 400 kA/m or more and a non-magnetic material with a thickness tadapted to isolate two adjacent isotropic magnets where the ratio of t/tis eight or more and which are stacked on one another in multiple layers in the rotation axis direction, wherein at least two pole pairs are provided and a mean magnetic path of in-plane direction having a permeance (B/μoH) of five or more achieved by the magnet alone is provided, whereby eddy current is reduced. Also disclosed are a radial gap type brushless DC motor, a PM stepping motor and an electric generator which incorporate the above described micro rotor.