Comprehensive analysis on the effect of static air gap eccentricity on cogging torque

Three phase permanent magnet synchronous motors are widely used in high performance industrial drives. The torque produced by these machines has a pulsating component which is a function of actual rotor position. The main part of this component is usually cogging torque. A variety of special machine construction techniques exist for reducing cogging torque which is affected greatly by mechanical misalignments. If the manufacturing tolerances are not well defined cogging may vary in a wide range. If analysis is made by several cases of each kind of mechanical misalignments, manufacturing tolerances can be defined.