| 主权项 |
1. A permanent magnet embedded motor comprising:
a stator in which a plurality of teeth sections, around which stator winding is wound, are arranged in a circumferential direction at equal angle intervals via slot sections; and a rotor in which a plurality of permanent magnets are embedded at the equal angle intervals in the circumferential direction, the rotor being rotatably held on an inner circumferential surface of the stator, wherein an outer circumferential surface of the rotor includes a plurality of divided outer circumferential surfaces divided at the equal angle intervals in the circumferential direction to correspond to the permanent magnets, the plurality of divided outer circumferential surfaces being divided by radial lines, each of which connects a center of the rotor and a middle point between adjacent ends of the plurality of permanent magnets so that a pair of the radial lines define each of the plurality of divided outer circumferential surfaces, each of the plurality of divided outer circumferential surfaces includes:
a first curved surface, a radial direction distance of which from an axis of the rotor is maximized in a circumferential direction center of the divided outer circumferential surface, formed from the circumferential center to circumferential direction both ends, the first curved surface includes, in a predetermined section formed from the circumferential direction center to the circumferential direction both ends of the divided outer circumferential surface, a first arcuate surface having the axis of the rotor as a central axis and having a radial direction distance from the axis of the rotor in the circumferential direction center of the divided outer circumferential surface as a first radius, andsecond curved surfaces formed from the circumferential direction both ends to the circumferential direction center of the divided outer circumferential surface by a substantially fixed second arcuate surface having the axis of the rotor as a central axis and crossing the first curved surface, a radial direction distance between the second arcuate surface and the inner circumferential surface of the stator being larger than a radial direction distance between the first curved surface and the inner circumferential surface of the stator, wherein the first curved surface further includes, in a section from ends of the predetermined section to crossing parts with the second curved surfaces, a third arcuate surface having a third radius smaller than a second radius of the second arcuate surface forming each of the second curved surfaces, and a distance between both ends of the first curved surface crossing the second curved surface is smaller than width of the permanent magnets in a direction orthogonal to a radial direction in the circumferential direction center of the divided outer circumferential surface. |
