Stator frame for dynamoelectric machine and method for making same

A stator frame for use in a dynamoelectric machine, said stator frame including a generally annular wall having opposite ends and defining a generally cylindrical axial bore intersecting said opposite ends and adapted to receive a stator core, said annular wall having greater radial thickness adjacent said opposite ends than the radial thickness of said annular wall intermediate said opposite ends, and including a plurality of longitudinal cooling fins formed externally longitudinally along and integral with said annular wall so as to extend substantially the full longitudinal length of said annular wall, said cooling fins having greater height along said intermediate longitudinal length of said wall than at said increased thickness ends of said wall such that the rigidity of the intermediate length of said annular wall is substantially enhanced by the rigidity of fins tied to the increased thickness opposite ends of said annular wall.

A stator frame for a dynamoelectric machine, said stator frame being made by a lost foam process using an integral single-piece vaporizable pattern operative to produce a stator frame housing having a generally annular wall defining an axial bore and having opposite ends lying in planes normal to the axis of said bore, a plurality of external cooling fins formed integral with and extending longitudinally of said annular wall, and a plurality of mounting foot pads formed integral with said annular wall and defining coplanar bottom surfaces enabling the stator frame to be supported on a support surface in a predetermined orientation, said mounting foot pads each being integrally interconnected to said annular wall through a connecting web extending between the corresponding foot pad and said annular wall and lying in a plane inclined to the bottom surface of the corresponding foot pad, and reinforcing ribs formed integral with and perpendicular to each of said connecting webs and the associated mounting foot pad, whereby said reinforcing ribs enable said connecting webs to be made relatively thin without diminishing the support strength of said mounting foot pads.

A dynamoelectric machine comprising in combination, a stator housing having a generally annular wall defining opposite ends and a longitudinal cavity, a stator core within said longitudinal cavity, a pair of end frames secured to the opposite ends of the stator housing, and a rotor rotatably supported by said end frames and extending coaxially through said stator core, said stator housing having a plurality of cooling fins formed integral with and extending longitudinally along the exterior of said annular wall, said cooling fins and annular wall being configured to establish a ratio of effective cooling fin height to annular wall outer diameter of at least 4.0 considered at substantially the longitudinal center of said stator housing.