Several Technical Problems on Rare earth Iron Magnets Used in Electrical Machines

摘要

NdFeB permanent magnet material is exceedingly well in magnetic performance with high magnetic energy product, good mechnical and physical characteristics, therefore, it is a type of desirable permanent magnet material for electric machines. In comparison with other PM electric machines such as AINiCo and SmCo, NdFeB PM electric machines are superior to the others in performance and reliability but not in price. Besides there, the abundant resources of rare earth Nd material have laid a very firm foundation for developing high performance PM electric machines. NdFeB PM electric machines are with highly popularizing and applying values. Utilization of NdFeB PM in DC servo motor for ocean robot has resulted in light in weight, small in volume, high in efficiency and rapid in response. This paper mainly discusses the optimization design of magnetic circuits by means of the study of NdFeB PM DC motors for ocean robot. Thermal stability considerations, corrosion properties and manufacturing technology are described as well as the effect of their magnetic properties on motor performance.