Patent ID: 7545642

Claim:
An automotive dynamoelectric machine comprising: a rotor that is rotatably disposed inside a case by means of a shaft; a stator that is disposed inside said case so as to surround an outer circumference of said rotor; a heat-generating element that is mounted to an element mount surface of a heatsink and that controls rotation of said rotor electrically; an air intake aperture and an air discharge aperture that are disposed through said case; and a fan that is fixed to an axial end surface of said rotor and that rotates with said rotor so as to generate a cooling airflow that is sucked into said case through said air intake aperture and is discharged outside said case through said air discharge aperture, wherein: a large number of ventilating apertures that have a circular cross section are disposed through said heatsink so as to extend from an air intake apertured surface to an air discharge apertured surface so as to have aperture directions that are parallel to each other and parallel to said element mount surface; and said heatsink is disposed such that said air intake apertured surface faces said air intake aperture and said aperture directions of said ventilating apertures are aligned in a direction of flow of said cooling airflow.