Dynamo-electric machine

A rotating electric machine comprising:

• a plurality of annular ventilating passages formed between a stator frame and a stator iron core and arranged in parallel to one another in an axial direction of the stator iron core, each of the plurality of annular ventilating passages being provided for a respective portion of said stator iron core and surrounding and communicating with an outer periphery thereof;
• a rotor iron core defining an air gap with an inner periphery of said stator iron core;
• a rotating shaft formed integral with said rotor iron core and extending in the axial direction thereof;
• a pair of boosters, a respective one of said pair of boosters being disposed on said rotating shaft and proximate to an end thereof, for boosting a coolant and causing the coolant to flow inward of the rotating electric machine;
• a plurality of coolers for cooling the boosted coolant, each of said plurality of coolers being provided for a respective one of said plurality of annular ventilating passages;
• a plurality of radially extending ventilating ducts formed in said stator iron core and being spaced from one another in the axial direction thereof, each of said plurality of radially extending ventilating ducts permitting the boosted coolant to flow in radial direction through said stator iron core;
• and
• a ventilating circuit which allows the coolant boosted by one of said pair of boosters to flow through the cooler for said annular ventilating passage for a center portion in the axial direction of said stator iron core, the center portion of said stator iron core in a direction from the outer periphery to the inner periphery thereof through the radially extending ventilation ducts therein, a part of the air gap, an adjacent portion of said stator iron core in a direction from the inner periphery to the outer periphery thereof through said radially extending ventilating ducts therein, said annular ventilating passage provided for the adjacent portion of said stator iron core and said cooler associated with said annular ventilating passage for the adjacent portion of said stator iron core to the suction side of the one of said pair of boosters.