| 摘要 |
At least three magnet accommodation holes for accommodating magnets that compose a magnetic pole are formed in the peripheral direction of a rotor core (8), the holes being arranged in the peripheral direction of the rotor core (8) in a number corresponding to the pole number, and when the lamination thickness of the rotor core (8) is defined as X, the lamination thickness of the stator core (4) is defined as Y, the cross-section area of the iron core surrounded by wire connecting the centers of the inner-diameter side surfaces of the magnet accommodation holes is defined as S3, the cross-section area of the outer-periphery iron core provided between the outer-diameter side surface of the magnet accommodation holes and the outer-periphery surface of the rotor core (8) is defined as S2, the cross-section area found by subtracting cross-section area S2 and cross-section area S3 from the cross-section area of the rotor core (8) is defined as S1, and the magnetic force of the magnet is defined as a, both ends of the rotor core (8) overhang both ends of the stator core (4) and the rotor core (8) is formed so as to fulfill the relationships X>Y and X<Y(1+(S2/S1)/a×2). |
