Patent ID: 8304951

Claim:
A dynamoelectric machine comprising: a rotor having: a pole core having: a boss portion; a pair of yoke portions that are disposed so as to extend radially outward from two axial end edge portions of said boss portion; and a plurality of claw-shaped magnetic pole portions that are disposed so as to extend in an axial direction alternately from each of said pair of yoke portions, and that are arranged circumferentially so as to intermesh with each other, trough portions being formed on respective portions of said yoke portions between circumferentially adjacent claw-shaped magnetic pole portions, and said pole core being fixed to a rotating shaft that is inserted through a central axial position of said boss portion; and a field coil that is housed inside a space that is surrounded by said boss portion, said pair of yoke portions, and said plurality of claw-shaped magnetic pole portions; and a stator that is disposed so as to surround an outer circumference of said rotor so as to have a predetermined air gap interposed, wherein: a magnet holder is disposed so as to span over said trough portions by being connected to each of consecutive yoke portions at locations above a curved bottom of said trough portions, an inner part of the magnet holder having a trapezoidal cross section perpendicular to a longitudinal direction of the magnet holder such that two inner side surfaces of the magnet holder are inclined toward each other, and a permanent magnet is held in said magnet holder so as to face an inner circumferential surface near a tip end of said claw-shaped magnetic pole portions so as to have a predetermined clearance.