Patent ID: 8368274

Claim:
A dynamoelectric machine comprising: a rotor comprising: a pole core comprising: 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, a trough portion that curves radially inward being formed on a portion of each 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 wound onto a bobbin, and 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, said dynamoelectric machine comprising: holding grooves that are recessed into said yoke portions in a non-piercing state so as to have openings on respective facing portions of inner wall surfaces of said trough portions, so as to have openings at axially inner ends of said yoke portions, and so as to have groove directions in an axial direction, and in which an end surface in a groove length direction constitutes a stopping surface; magnet holders that are made of a magnetic material that are disposed so as to span said trough portions radially inside inner circumferential surfaces near tip ends of said claw-shaped magnetic pole portions by being fitted from axially inside into each of said holding grooves that are recessed so as to face each other on said trough portions such that circumferential and radial motion is restricted by inner wall surfaces of said holding grooves and axially outward movement is restricted by said stopping surface, and in which interfitting grooves are formed so as to have openings on surfaces that face said inner circumferential surfaces near said tip ends of said claw-shaped magnetic pole portions, so as to have groove directions in an axial direction, and so as to pass through in said axial direction; and permanent magnets that are fitted into said interfitting grooves and are held by said magnet holders so as to face said inner circumferential surfaces near said tip ends of said claw-shaped magnetic pole portions.