Motor Magnets Types And Application Requirements

Depending on the material used, three common types of motor magnets are used: neodymium iron boron (NdFeB) motor magnets, ferrite magnets, alnico (AlNiCo), and samarium cobalt (SmCo) magnets. Different magnets have different performance and magnetic field waveform requirements depending on their application: ① As rotors, they require a high surface field on their outer arc surface, typically with a saddle-shaped waveform, similar to a square wave or a sine wave. Some designs may include multiple harmonics. ② As stators, their selection depends on the motor's output requirements, sparking, and noise requirements. Stator magnets have a high surface field on their inner arc surface. Due to their shape and production characteristics, their waveform is primarily a saddle-shaped waveform. This waveform produces high output, but also produces sparking noise and high no-load current.