Rotor for a dynamoelectric machine

DETAILED DESCRIPTION It is the principal object of the invention to provide a dynamoelectric machine with a new and improved rotor.
More specifically, it is an object of the invention to provide such a machine with a means for both reducing eddy current losses thereby reducing the need for cooling and for providing improved cooling that will not disrupt magnetic efficiency within the rotor itself.
According to one facet of the invention, an exemplary embodiment of the invention achieves the foregoing object in a dynamoelectric machine including a stator and having a rotor journaled for rotation about an axis within the stator.
The rotor includes a rotor body having "n" axially elongated poles spaced from one another by axially extending recesses between adjacent poles with each pole having a base and a tip.
An axial coolant passage is located at or radially inward of the base of each of the poles and entirely radially outward of the axis at a location closer to the pole tips than to the axis.
As a consequence of the foregoing construction, the coolant passage does not narrow the magnetic flux path from one pole to another to the point where it could be saturated to reduce magnetic efficiency.
According to a highly preferred embodiment of the invention, additional axial cooling passages are disposed in the body and are located just radially inward of the recesses.
In a preferred embodiment, means are provided for flowing coolant through the passages and comprise vanes on the ends of the rotor for flowing a gaseous coolant through the passages.
Additionally, radial passages extend to the axially extending passages from the periphery of the rotor, generally centrally thereof.
Coolant may therefore flow from both ends of the rotor to the radial passages to be discharged therefrom, minimizing the possibility of the creation of hot spots in the rotor.
According to another facet of the invention, there is provided a dynamoelectric machine that includes a stator and a rotor mounted for rotation about an axis within the stator