Ventilated end turns for rotor windings of a dynamoelectric machine

A rotor for a dynamoelectric machine, said rotor comprising:

• A body portion defining axial coil slots circumferentially spaced on the periphery of the rotor body on either side of a pole portion of the rotor body;
• and,
• a rotor winding, said rotor winding including:
• a first plurality of axially extending slot lying coil portions disposed in said coil slots;
• a first plurality of end turns extending beyond the rotor body, said first plurality of end turns including a first plurality of axial end turn portions formed by extensions of the first plurality of slot lying coil portions and a first plurality of end turn circumferential portions connecting said first plurality of axial end turn portions;
• a second plurality of axially extending slot lying coil portions disposed in said coil slots, respective ones of said second plurality of slot lying portions electrically insulated from respective adjacent ones of said first plurality of slot lying portions;
• a second plurality of end turns extending beyond the rotor body and alternately disposed with said first plurality of end turns, respective ones of said second plurality of end turns electrically insulated from, yet disposed in heat flow communication with respective adjacent ones of said first plurality of end turns, said second plurality of end turns including a second plurality of axial end turn portions formed by extensions of the second plurality of slot lying portions and a second plurality of end turn circumferential portions connecting said second plurality of axial end turn portions, respectively.
• a first plurality of surfaces respectively disposed on said first plurality of end turns said first plurality of surfaces for defining a respective first plurality of coolant gas flow channels longitudinally extending along said first plurality of end turns, said first plurality of gas coolant channels having a respective first plurality of gas coolant inlets respectively disposed in said first plurality of end turn circumferential portions;
• the first plurality of gas channels extending along respective first axial end turn portions and end turn circumferential portions;
• a second plurality of surfaces respectively disposed on said second plurality of end turns, said second plurality of surfaces for defining a respective second plurality of coolant gas flow channels longitudinally extending along said second plurality of end turns, said second plurality of coolant gas channels having a respective second plurality of gas coolant inlets respectively disposed in said second plurality of axial end turn portions, the second plurality of gas coolant channels extending along respective second axial end turn portions whereby the second plurality of gas coolant channels are coextensive with only a portion of the first plurality of gas coolant channels.