Abstract: An electrical machine with a radial path air-cooled rotor is provided with prewhirl inlet guide vanes in the coolant inlet duct. The guide vanes are fixed members spaced from each other in an arc around the duct with their radial inward edges advanced in the direction of rotation of the rotor from the radial outer edges and preferably have a smoothly curved airfoil configuration so as to smooth and facilitate air flow through the end turn region and the slot channels.

Abstract: An electrical machine with a radial path air-cooled rotor is provided with a stator end turn shell structure of a smoothly curved configuration that, with a like smoothly curved configuration on the outer wall of the air inlet duct, smooths and facilitates air flow through the exhaust passage and serves as a gas diffuser and noise baffle.

Abstract: A ventilation system is provided for dynamoelectric machines such as hydro generators having salient pole rotors and in which the rotor and stator have separate ventilation systems sealed from the air gap. The stator ventilation system includes radial vent ducts with longitudinal ducts in the stator core extending between adjacent radial vent ducts. The longitudinal ducts are sealed from the air gap and are disposed in the region of the stator windings, preferably extending through the teeth. Ventilating air flows radially inward through the vent ducts, longitudinally through the longitudinal ducts from one vent duct to the next, and radially outward to the external circuit where it is circulated through coolers, by means of a blower or otherwise.