| 摘要 |
PROBLEM TO BE SOLVED: To make flux uniform when controlling weakening flux, to suppress generation of a high voltage, to decrease a terminal voltage according to the increase of the weakening flux, by providing two or four recessed parts per pole between one or both of permanent magnets where a rotor is divided into two layers and the outer-periphery part of the rotor. SOLUTION: Two recessed parts 7 per pole are provided between both edges 1a of a permanent magnet 1 at an outer-periphery side and an outer-periphery part 3b of a rotor. The recessed part 7 is positioned inside in a radial direction as compared with the outer-periphery part 3b, has an arcuate part 9 and an inclined part 8, and shows the section shape of a mortar as a whole. Since the recessed part 7 increases the substantial air gap being seen from a stator 5, steep gap flux is decreased, and the inclined part 8 especially contributes to smooth decrease, thus preventing flux from greatly fluctuating even a weakening flux current is increased, uniformly making the flux weak, suppressing generation of a high voltage, and decreasing a terminal voltage according to the increase of the weakening flux current.
|
