A SINGLE PHASE SYNCHRONOUS AC MOTOR

摘要

A single phase synchronous AC motor includes a laminated iron stator (1) carrying a single phase winding (3, 4) and a permanent magnet rotor (2) located within a stator bore (5). The stator bore is elongate in shape and is generally symmetrical about a minor axis (13) and a major axis (14). A permanent magnet reluctance torque smoothes out the twice electrical frequency torque pulsation due to the single phase winding. Substantially constant torque is obtained at all rotor positions when rated load torque is applied. The motor may be designed such that constant torque is achieved for any rate value of load torque corresponding to a fractional value of the amplitude of the permanent magnet reluctance torque. The motor may be designed to obtain a useful ratio of pullout to rated torque for operation from a mains AC supply.