| 摘要 |
This invention is concerned with providing a cylinder type anisotropic magnet, which enhances the total magnetic flux generated from the magnetic poles and improves the motor cogging characteristics, and its manufacturing method. At the same time, it improves the assembly efficiency, miniaturization is accomplished by increasing the total magnetic flux generated from the magnetic poles. In order to supply a motor which reduces noises, the cogging characteristics must be improved. A non-magnetic ring is placed at the outer circumference of an elliptical molding space in which a longer diameter aligns with the magnetization direction between a pair of magnetic poles, and a pair of magnets are placed in opposite parts of the long diameter direction. After sintering the elliptical molded body which is molded by an apparatus in which a core magnet body is placed at the center, by administering the cylindrical process, a cylinder type anisotropic ferrite magnet with a diameter D1 is obtained, and in which a pair of opposing parts have radial anisotropy within a specified angle range, and the remainder is orthogonal. For example, a motor is obtained by pressure fastening the ferrite magnet to the inner circumference of a cylinder type yoke to form stator, and by placing rotor at the inner circumference space of the said ferrite magnet. A cylindrical cylinder type anisotropic sintered magnet can be obtained without cracking when sintered, by placing a unit body cylinder type anisotropic magnet in which a specified part is radial anisotropic and the remainder is orthogonal anisotropic, cogging will be reduced by taking advantage of each anisotropic magnet's good characteristics. |
