Abstract: Due to the inevitable deviation, processing and manufacturing quickly in addition to magnetic introduced asymmetric component, which makes the electromagnetic radial force content more rich. Mainly considering the stator roundness, additional gas in addition to the eccentric and eccentric static and dynamic three process factors, analyzing its influence on electric magnetic force. Of different process factors on first explains, cogging torque of motor, analyzes the mechanism of the radial force and electromagnetic, further under different process deviation calculated gas permeance function, and calculate the corresponding cases motor cogging torque, the analytical expressions of radial force. On the basis of given different process deviation case to introduce the cogging torque, frequency harmonic electromagnetic radial force frequency doubling and order harmonic content, instructions from the mechanism of the influence of different process deviation on the electromagnetic force.

Key words: Electromagnetic radial force, Cogging torque, Stator roundness, Additional air gap, Static ecentric, Dydamic eccentric, Process deviation