Patent ID: 8148865

Claim:
A permanent magnet rotating electrical machine, comprising: a stator; and a rotor with a plurality of permanent magnets insertedly arranged in an outer circumferential region of a rotor core, wherein each permanent magnet has inclined surfaces on an outer circumferential surface side of the rotor, and thinnest portions adjacent to respective permanent magnets of an opposite polarity, wherein each permanent magnet has a convex-shaped cross-section, wherein each permanent magnet has a cross section comprising a combination of plural lines and plural arcs continuous from the lines; and wherein each corner of each permanent magnet is formed only of an arc on the outer circumference side and on an inner circumference side of the rotor and radii of the arcs at corners on the outer circumference side of the rotor are larger than radii of the arcs at corners on the inner circumference side of the rotor.