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:
Dec. 22, 2009
Filed:
Dec. 12, 2007
Yuzuru Suzuki, Kitasaku-gun, JP;
Takayuki Yamawaki, Kitasaku-gun, JP;
Masaki Kagawa, Kitasaku-gun, JP;
Hiroyuki Furusaki, Kitasaku-gun, JP;
Yuzuru Suzuki, Kitasaku-gun, JP;
Takayuki Yamawaki, Kitasaku-gun, JP;
Masaki Kagawa, Kitasaku-gun, JP;
Hiroyuki Furusaki, Kitasaku-gun, JP;
Minebea Co., Ltd., Kitasaku-gun, JP;
Abstract
In a stepping motor including two stators and a rotor having two magnets, three dimensional relations, specifically a relation of Lm/Ls, another relation of d/2Lm, and still another relation d/D, are optimally determined while satisfying their respective ranges: 0.35≦Lm/Ls≦0.45; 0.77≦d/2Lm≦1.10; and d/D≦0.45, where Lm is the axial dimension of the magnet, Ls is the axial dimension of the stator, d is the outer diameter of the magnet, and D is the outer diameter of the stator, whereby a space for accommodating a sufficient number of coil turns is secured maximally in the stator, and the inertia and the cogging torque of the rotor are reduced maximally, which leads to producing the highest possible torque at a high rotation speed range required.