| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for reducing the amount of permanent magnet used, while preventing demagnetization of the permanent magnet.SOLUTION: A first magnet insertion hole 161 and a second magnet insertion hole 162 are provided in the main magnetic poles A-D of a rotor 150 along the direction of rotation R, when viewed in a cross section perpendicular to the axial direction. The thickness W2 of a second permanent magnet 172 inserted into the second magnet insertion hole 162 is set smaller than the thickness W1 of a first permanent magnet 171 inserted into the first magnet insertion hole 161. A slit 166 extending in the radial direction is provided between a bridge 163, formed between the first magnet insertion hole 161 and second magnet insertion hole 162, and the outer peripheral surface 150a of the rotor 150. A voltage is applied to the stator winding of each phase at a moment of time leading a set angle α ahead of an induction voltage induced in the stator winding of each phase. Maximum value of the set angle α is determined based on the number P of pole pairs of the stator, the opening angle &thetas;1 on the outer peripheral side of the slit 166, and the opening angle &thetas;2 of between adjoining teeth. |
