SEALED MOTOR-DRIVEN COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To improve holding power of an Nd-Fe-B based sintered magnet while ensuring a magnetic force of a motor.SOLUTION: A sealed motor-driven compressor comprises a compression mechanism section for compressing a refrigerant, and a motor for driving the compression mechanism section. The motor comprises a stator including a coil, and a rotor including an iron core and a permanent magnet. The permanent magnet is composed of an Nd-Fe-B compound to which a middle-heavy rare earth element has been added. The refrigerant is R32. The quantity of the middle-heavy rare earth element per unit volume within 5 nm from a grain boundary of a mother-phase grain of the Nd-Fe-B compound is more than the quantity of the middle-heavy rare earth element per unit volume inner than 5 nm from the grain boundary of the mother-phase grain.SELECTED DRAWING: Figure 4