Patent ID: 8324782

Claim:
A rotary electric 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 shaft that is inserted through a central axial position of said boss portion; and a field coil that is wound onto a bobbin that is mounted to said boss portion, 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; a stator that is disposed so as to surround an outer circumference of said rotor; and a permanent magnet that is disposed in said trough portion so as to face an inner circumferential surface near a tip end of said claw-shaped magnetic pole portions, wherein said rotary electric machine further comprises: an interfitting groove that is disposed in a bottom portion of said trough portion so as to have a groove direction that is axial and so as to extend axially outward from axially inside; a rotation arresting portion housing recess portion that is formed on an axially inner opening edge portion of said interfitting groove on said yoke portions; a magnet holding seat comprising: an interfitting portion; and a magnet holding portion that is formed on an upper portion of said interfitting portion, said magnet holding seat being disposed in said trough portion such that radial movement is restricted by said interfitting portion being fitted into said interfitting groove; and a rotation arresting portion that is disposed so as to project axially outward from a flange portion of said bobbin; wherein said magnet holding seat comprises a stepped portion that is formed by setting back an axially inner end surface of said interfitting portion axially outward relative to an axially inner end surface of said magnet holding portion; wherein said bobbin is mounted to said rotor such that said rotation arresting portion is housed in a space that is formed by said rotation arresting portion housing recess portion and said stepped portion so as to restrict circumferential movement; and wherein said permanent magnet is made into a quadrangular prism that has a rectangular bottom surface, and is held by said magnet holding seat by placing said bottom surface on an upper surface of said magnet holding portion, and fixing to said magnet holding seat a cover that is mounted from radially outside to restrict circumferential, axial, and radial movement.