Patent ID: 7067954

Claim:
An automotive rotary electric machine comprising: a rotor having: a rotor core having: a cylindrical boss portion; a first yoke portion disposed so as to extend radially outward from a first axial end of said boss portion; a second yoke portion disposed so as to extend radially outward from a second axial end of said boss portion; a plurality of first claw-shaped magnetic pole portions each disposed so as to extend toward said second axial end from said first yoke portion, arranged at a predetermined pitch in a circumferential direction, and having a radially-outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides; and a plurality of second claw-shaped magnetic pole portions each disposed so as to extend toward said first axial end from said second yoke portion, arranged at a predetermined pitch in a circumferential direction, having a radially-outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides, and arranged so as to alternate with said first claw-shaped magnetic pole portions in a circumferential direction; and a field winding installed on said boss portion, said rotor being disposed so as to be rotatable around a shaft inserted through a central axial position of said boss portion; a stator having: a cylindrical stator core; and a stator winding installed in said stator core, said stator core being disposed so as to surround said rotor core coaxially; and permanent magnets constituted by first and second permanent magnets disposed between each circumferentially-adjacent pair of said first and second claw-shaped magnetic pole portions so as to contact a circumferential side surface of said first and second claw-shaped magnetic pole portions, wherein an axial length (L 1 ) of said stator core relative to an axial distance (L 2 ) between facing end surfaces of said first and second yoke portions is constructed so as to satisfy an expression L 1 >L 2 , wherein said first and second permanent magnets are each formed so as to have a cross-sectional shape positioned inside a circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions, wherein said first and second permanent magnets are each formed so as to have a shape matching a tip portion of said circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions; and wherein axial positions of a tip portion and a base end portion of said first permanent magnets are aligned with axial positions of a base end portion and a tip portion of said second permanent magnets respectively.