In PM motors, all the PM poles usually have the same polearc coefficients.
通常情况下，永磁电机各磁极的极弧系数相等。
2
A permanent magnet with a wide polearc circular ring structure is arranged on the rotor and fixed with a non-magnetic thin-wall outer ring.
转子上装有宽极弧圆环结构的永磁体，永磁体用非磁性的薄壁外圈固定。
3
The opening air-gaps with circular main polearc are usually used to improve the potential curve of commutator on non-compensable d. c. traction motors.