ROTATOR AND PERMANENT MAGNET MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a technique by which efficiency of a permanent magnet motor can be improved while using ferrite magnets as permanent magnets.SOLUTION: Into first magnet insertion holes 111 and second magnet insertion holes 112 are inserted first permanent magnets 121 and second permanent magnets 122 respectively. A first side wall 111b of the first magnet insertion hole 111 and a second side wall 112c of the second magnet insertion hole 112 form an inner circumferential bridge portion 106; and second side walls 111c of the first magnet insertion holes 111 and first side walls 112b of the second magnet insertion holes 112 form inter-pole bride portions 107. As the permanent magnets, ferrite magnets, in which a ratio (HK/Hcj) of a magnetic field HK corresponding to 90% of residual magnetic flux density Br to holding force Hcj in a J-H demagnetization curve is within a range between 0.8 and 0.85, are used.