Patent ID: 7560851

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 axially alternately from each of said pair of yoke portions, and that are arranged circumferentially so as to intermesh with each other, said pole core being fixed to a shaft that is inserted through a center axial portion 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, said dynamoelectric machine comprising: a permanent magnet holding portion that is disposed integrally so as to project from said yoke portion, said permanent magnet holding portion facing an inner circumferential surface near a tip end of said claw-shaped magnetic pole portion; an arc-shaped magnet holding aperture that has a C-shaped cross section that is formed in said permanent magnet holding portion so as to have an aperture center that is oriented axially, in which at least one axial end is open, and that opens radially outward; a magnet holding member that is made of a nonmagnetic material that is fitted into and held by said magnet holding aperture; and a permanent magnet that is held by said magnet holding member so as to face said inner circumferential surface near said tip end of said claw-shaped magnetic pole portions, that is prepared into a prismatic body that has a quadrilateral cross section perpendicular to an axial direction, and that is magnetically oriented in a reverse direction to an orientation of a magnetic field produced by said field coil.