| 摘要 |
<p>In a permanent magnet type motor the stator of which incorporates a rotator wherein permanent magnets are so buried as to be arrayed circumferentially in the magnet inserting section of a yoke, each magnet is divided into a center magnet located at the center in the width direction of the magnet inserting section and an end magnet located at an end of the magnet inserting section, the coercive force of the end magnet is made larger than that of the center magnet, and the flux density of the center magnet is made larger than that of the end magnet. Since the coercive force of the end magnet located in the easy-to-demagnetize side by a reverse magnetic field produced by a stator current, the demagnetization of the magnets is prevented as the whole. Since the flux density of the center magnet located on the difficult-to-demagnetize side is large, the maximum torque and efficiency of the motor are enhanced by this large magnetic flux.</p> |
