| 摘要 |
PROBLEM TO BE SOLVED: To get a motor which is simple of constitution, small in cogging torque, and large-output by specifying the relation between the number of magnetic poles of a permanent magnet and the number of magnetic poles of a salient pole. SOLUTION: The relation between the number P of magnetic poles of a permanent magnet and the number M of magnetic poles of a salient pole is made such that M=3n and P=3m±1 (where n is an integer of 2 or over). For example, the stator is equipped with twelve salient magnetic poles 3 where armature windings 2 are wound concentrically around, and for a permanent magnet rotor 6, inside the yoke 5, fourteen permanent magnet magnetic poles magnetized alternately into N and S are arranged in opposition to the salient magnetic poles 3. Hereby, the number of pulsations of cogging torque per revolution becomes eighty four being the least common multiple between the number 14 of permanent magnet magnetic poles and the number of salient magnetic pole 12, and cogging torque is lightened. On the other hand, for winding availability (winding coefficient), the short-pitch wining factor is cos30/2=0.966, and also the coefficient by the distribution of the salient magnetic pole is cos30/2=0.966, and in all it becomes 0.966×0.966=0.933, thus it can be improved more than conventional one. |
