| 摘要 |
PROBLEM TO BE SOLVED: To do away with the use of a separate part for the balance weight for a rotor core and provide a core itself with the function of the balance weight in a permanent-magnet motor. SOLUTION: In an inner rotor-type permanent-magnet motor, its rotor core 10 is constituted of a first core 11, which develops only reluctance torque and a second core 12 which develops at least magnet torque. Arc-shaped slits 11b are formed at equal intervals on the rim of the first core 11 for the purpose of increasing reluctance torque, and further part of the core (cut-off portion k), including the slits 11b, is cut off in order to provide a balance weight. Permanent magnets 12a in a number equivalent to the number of poles are embedded on the rim of the second core 12 at equal intervals. When the first and second cores 11, 12 are stacked up to form the rotor core 10, the arc-shaped slits 11b are embraced in the cross sections of the permanent magnets 12a. Holes 11a for flux barriers are formed on the first core 11 facing opposite both the ends of the permanent magnets 12a. |
