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. 27, 2013
Filed:
Apr. 13, 2011
Yuzuru Suzuki, Miyota-machi, JP;
Yuuki Takahashi, Miyota-machi, JP;
Yuzuru Suzuki, Miyota-machi, JP;
Yuuki Takahashi, Miyota-machi, JP;
Minebea Co., Ltd., Nagano, JP;
Abstract
A brushless DC motor provided with nine slots and eight poles includes a stator including a stator core having pole teeth on the outer circumference thereof and a coil wound around each pole tooth; a rotor disposed at an outside position of the outer circumference of the stator via a gap and having a multiply magnetized permanent magnet with plural magnetic poles; a pole tooth surface formed at a portion of the pole tooth and facing an inner circumference of the rotor; a recessed portion formed on the pole tooth surface; and a slot formed between the adjacent pole teeth and extending a first angular range around a rotational center of the rotor; in which the recessed portion extends in a second angular range around the rotational center of the rotor, the second angular range is 1.2 to 3.0 times the first angular range, the recessed portion has a radial depth which is 0.5% or more of an inner diameter of the permanent magnet, the pole tooth extends in a third angular range around a rotational center of the rotor, and the third angular range is 0.58 to 0.8 times a value which is obtained by dividing 360 degrees by the number of magnetic poles of the permanent magnet.