Title:
MOTOR DEVICE, PERMANENT MAGNET THEREFOR AND METHOD OF MANUFACTURING PERMANENT MAGNET FOR MOTOR DEVICE
Document Type and Number:
Japanese Patent JP3650386
Kind Code:
B2
Abstract:
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.
Inventors:
Isamu Takehara
Shinji Kinoshita
Hiromitsu Goto
Shinji Kinoshita
Hiromitsu Goto
Application Number:
JP2002306896A
Publication Date:
May 18, 2005
Filing Date:
October 22, 2002
Export Citation:
Assignee:
Seiko Instruments Inc.
International Classes:
H01F13/00; H01F41/02; H02K15/03; (IPC1-7): H02K15/03; H01F13/00; H01F41/02
Domestic Patent References:
| JP2002237406A | ||||
| JP2002199668A | ||||
| JP2001118738A | ||||
| JP63098606U |
Attorney, Agent or Firm:
Takashi Kawai
Hitoshi Nakano
Hitoshi Nakano
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