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. 21, 2012
Filed:
Jan. 30, 2009
Masayuki Okubo, Kiryu, JP;
Masayuki Okubo, Kiryu, JP;
Mitsuba Corporation, Gunma, JP;
Abstract
A brushless motor has a 2P3S×n structure, in which a ratio (W) of a circumferential width (Wm) of each of magnets to a length (Wp) of a chord formed between endpoints of an arc with a center angle θp=360°/pole-number 3n, the arc being included in an inner-diameter circle Cof each of the magnets, is in a range of 0.76<W=Wm/Wp<0.86. Therefore, in the brushless motor of the 2P3S×n structure, a skew angle may be set in a range of 36°≦θskew≦57° in terms of electrical angle, while a content ratio of a fifth harmonic component contained in an induced voltage of the brushless motor may be set in a range of 4.5% to 6.5% with respect to a fundamental wave.