| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rotary motor with built-in permanent magnet that can reduce cogging torque and can also reduce the usage amount of permanent magnets without reducing torque. SOLUTION: In a rotary motor with built-in permanent magnet having N slots 6 and P permanent magnet magnetic pole sections 11, in which P/N is set in the range of 2/3≤P/N≤43/45 and P<SB>0</SB>in an irreducible fraction P<SB>0</SB>/N<SB>0</SB>of the P/N is set to be an odd number, an pole arc ratioΨp is defined to be the ratio ofθpp/θp where an angle between two line segments assumed for a pair of flux barriers 21, each of which connects the center of a rotor core and one of corners that is closest to the surface of the rotor core 9, of a plurality of corners that a contour shape has when the cross-sections of the flux barriers 21 are viewed from one side of the axial direction of the rotor core 9, is indicated by theθpp and an angle obtained by dividing the full circumference angle of the rotor core by the number of the permanent magnet poles is indicated by theθp. Then, the pole arc ratio indicated byΨp is determined so as to satisfy the relationship ofΨp=2mP/N+P/4LCM (P, N)-2n, in which LCM (P, N) is the least common multiple between P and N, m and n are arbitrary natural numbers, and theΨp is larger than zero but smaller than one. COPYRIGHT: (C)2005,JPO&NCIPI
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