| 摘要 |
PROBLEM TO BE SOLVED: To provide a permanent magnet, etc. for a permanent magnet which is small in size and excellent in performance. SOLUTION: A cylindrical permanent magnet, which is used for a micro DC brushless motor used for a small-sized hard disk or the like, is constituted of an Sm-Co magnetic material having anisotropy. A sufficient magnetic force can be obtained even if the thickness is thinned by magnetizing the Sm-Co magnetic material into a multipole after magnetic field orientation. The manufacturing method of this permanent magnet comprises a step that magnetic field orientation and demagnetization are performed after forming the magnetic field by putting it in a mold. The permanent magnet is heat-treated and solidified, and then it machined to true up outside dimensions. Then, it is set in a magnetizing unit so as to be magnetized into the multipole. Since the thickness of the magnet is small, it can be magnetized easily, and also it can hold a strong magnetic force since it uses the Sm-Co magnetic material excellent in coercivity as a magnetic material. Therefore, a small-sized and high-performance motor device can be obtained. COPYRIGHT: (C)2004,JPO |
