| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve both a torque in a low-speed area and high efficiency under weak magnetic flux control in a high-speed area. <P>SOLUTION: A moving member 1 and a stator (armature) 20 are disposed to be counter to each other across an air gap 15. The moving member 1 is formed by embedding an N pole 2 and an S pole 3 alternately in a moving member core 4. The N pole 2 has a high coercivity magnet 2a and a low coercivity magnet 2b. The low coercivity magnet 2b is placed on the front side in the direction of drive of the moving member 1, while the high coercivity magnet 2a is placed on the rear side in the direction of drive of the moving member 1. The S pole 3 has a high coercivity magnet 3a and a low coercivity magnet 3b. The low coercivity magnet 3b is placed on the front side in the direction of drive of the moving member 1, while the high coercivity magnet 3a is placed on the rear side in the direction of drive of the moving member 1. At high rotation operation, an angle of lead of the current phase of the stator 20 is advanced temporarily to demagnetize the low coercivity magnets 2b and 3b, and then the angle of lead is set back to the original to obtain weak magnetic flux. <P>COPYRIGHT: (C)2010,JPO&INPIT |
