The Effect of Machine Geometry and Materials on the Starting Torque of the Shaded-Pole Induction Motor

A formula in closed form is presented for the starting torque of constant air-gap shaded-pole motors. The formula involves only the applied voltage, machine geometry, and material characteristics. It is subsequently used to evaluate the effect of geometry and material changes on the starting torque, confirming in a general manner some previously known results, and providing further insight into the design optimization process.