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Patent Searching and Data


Title:
DC BRUSHLESS MOTOR
Document Type and Number:
Japanese Patent JP2001069729
Kind Code:
A
Abstract:

To reduce the cogging torque of the rotor of a DC brushless motor and, at the same time, the number of the parts used in the rotor by forming permanent magnets in such a way that two poles of an N pole and an S pole are magnetized in the same parts when the rotor is multipolarized.

The rotor of a DC brushless motor is composed of permanent magnets, a yoke, and a shaft and the permanent magnets are arranged along the outer peripheral of the yoke. The rotor is multipolarized by constituting the permanent magnets in such a way that two poles of an N pole and an S pole are magnetized in the same parts. Therefore, the manufacturing facility and time of the rotor can be saved by reducing the increase of the number of parts accompanying the multipolarization and, at the same time, the efficiency of the rotor can be improved by reducing cogging torque and improving induced voltages as the effect of the multipolarization.


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Inventors:
KOJIMA TOMONORI
SUGIYAMA TADAO
Application Number:
JP1999000244779
Publication Date:
March 16, 2001
Filing Date:
August 31, 1999
Export Citation:
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Assignee:
HITACHI LTD
International Classes:
H02K29/00; F16H39/00; H02K1/27; H02K15/03; H02K21/14; (IPC1-7): H02K15/03; F16H39/00; H02K1/27; H02K21/14; H02K29/00
Attorney, Agent or Firm:
作田 康夫