SELF-STARTING TWO-POLE SINGLE-PHASE SYNCHRONOUS MOTOR

摘要

This motor has a permanent magnetic rotor which has two opposite pole faces on its circumference as a result of diametical magnetization. The rotor is arranged between two limbs of a stator provided with an exciter coil. The ends of the limbs partly enclose the rotor so that air gaps are formed. The air gaps are such that the magnetic field of the rotor will, when the motor is deenergised, produce a detent torque tending to drive the rotor to a rest position different from those at which the driving torque passes through zero in operation. The two apposite pole faces each extend around the rotor circumference for a distance which subtends an angle of less than 90 degrees at the rotor axis.