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:
Apr. 12, 2011
Filed:
Oct. 30, 2007
Isamu Takehara, Chiba, JP;
Shinji Kinoshita, Chiba, JP;
Hiromitsu Gotoh, Chiba, JP;
Seiko Instruments Inc., , JP;
Abstract
In a method for magnetizing a permanent magnet for a motor, the permanent magnet has a thickness t in a radial direction of the permanent magnet satisfying the relation of t≦πD/(NM−π), where D represents an inner diameter of the permanent magnet having a value of 20 mm or less, N represents the number of the magnetic domains of the permanent magnet, and M represents the number of alternating current phases for driving the motor. In a first magnetizing step, the permanent magnet is magnetized in one direction corresponding to the radial direction. In a second magnetizing step, the permanent magnet magnetized in the first magnetizing step is magnetized to form inverse magnetic domains that are arranged at regular intervals in the radial direction and that reverse the magnetizing direction of the permanent magnet.