MACHINE DYNAMO-ELECTRIQUE A REFROIDISSEMENT PAR FLUX INVERSE PERFECTIONNE

A reverse flow cooled dynamoelectric machine if provided with cooling gas passages extending through a fan ring and a portion of the rotor spindle to the end turns of the rotor winding in a direction substantially corresponding to the direction of flow of the cooling gas as modified by a tangential component imparted to the gas by the rotation of the fan ring. This direction is the vector sum of the longitudinal component of the velocity of the gas as it approaches the passages and the tangential component imparted by the rotation of the fan ring. The exit end of each passage is circumferentially displaced from the inlet end opposite to the direction of rotation. The centerlines of the gas passages lie in planes spaced around the axis of rotation of the rotor and parallel to this axis.