Invention Grant
US07626300B2 Radial anisotropic cylindrical sintered magnet and permanent magnet motor
有权
径向各向异性圆柱形烧结磁体和永磁电动机
- Patent Title: Radial anisotropic cylindrical sintered magnet and permanent magnet motor
- Patent Title (中): 径向各向异性圆柱形烧结磁体和永磁电动机
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Application No.: US10589235Application Date: 2005-06-20
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Publication No.: US07626300B2Publication Date: 2009-12-01
- Inventor: Koji Sato , Takehisa Minowa
- Applicant: Koji Sato , Takehisa Minowa
- Applicant Address: JP Tokyo
- Assignee: Shin-Etsu Chemical Co., Ltd.
- Current Assignee: Shin-Etsu Chemical Co., Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Westerman, Hattori, Daniels & Adrian, LLP
- Priority: JP2004-183214 20040622
- International Application: PCT/JP2005/011242 WO 20050620
- International Announcement: WO2005/124796 WO 20051229
- Main IPC: H02K21/12
- IPC: H02K21/12

Abstract:
In a radially anisotropic sintered magnet of annular shape, the remanence in a radial direction of the annulus increases and decreases at intervals of 90° in a circumferential direction of the annulus, and the remanence in a radial direction over the entire circumference of the annulus has a maximum of 0.95-1.60 T and a minimum equal to 50-95% of the maximum. In a permanent magnet motor comprising a plurality of stator teeth, the radially anisotropic annular sintered magnet is incorporated after it is magnetized in 4n poles (wherein n is an integer of 1 to 20) so that the boundary between N and S poles is located within the range that is centered at the radial direction where the remanence exhibits the minimum and extends ±10° therefrom in a circumferential direction. The radially anisotropic annular sintered magnet undergoes neither fracture nor cracking during the sintering and aging/cooling steps even when it is shaped to a low inner/outer diameter ratio and has satisfactory magnetic properties. A permanent magnet motor comprising the radially anisotropic annular sintered magnet is inexpensive and of high performance.
Public/Granted literature
- US20070170801A1 Radial anisotropic cylindrical sintered magnet and permanent magnet motor Public/Granted day:2007-07-26
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