Cooling arrangement for rotor end turns of reverse flow cooled dynamoelectric machines

A reverse flow cooled dynamoelectric machine comprising:

• a. a stator;
• b. a rotor disposed within the interior of said stator and defining with said stator a gas gap;
• c. said rotor including a spindle and a winding including end turns disposed radially outward from said spindle;
• d. a cylindrical turbine coupling formed integrally with said rotor spindle on the turbine end of said spindle for connecting said rotor to a driving turbine;
• e. a fan ring formed integrally with said spindle, said fan ring located axially inward from and proximate to said turbine coupling and having an inner diameter less than the outer diameter of said coupling;
• f. a fan mounted on said ring for circulating cooling gas through said rotor and said stator;
• and
• g. a plurality of passages extending through said fan ring and a portion of said spindle for the conduction of cooling gas to said end turns, said passages extending in a direction at an angle to the axis of said rotor and corresponding to the most practicable extent to the vector sum of the axial and tangential components of the velocity of the cooling gas entering said passages to minimize pressure losses in the flow of cooling gas through said passages.