Stator and rotor lamination construction for a dynamo-electric machine

A dynamo-electric machine comprising:

• a generally cylindrical casing;
• a stator core fixed in said casing and comprised of stator lamination plates of ferromagnetic material, said stator core having a cylindrical bore;
• a stator winding embedded in stator slots radially projecting from the bore and which slots extend generally axially along the core, with end turns of said winding extending beyond end faces of said stator core;
• a rotor supported in said bore for rotational movement and comprised of rotor lamination plates of ferromagnetic material, said rotor including conductive means for interacting with a magnetic field produced in an air gap between an outer periphery of said rotor and an inner periphery of the stator core when said stator winding is energized;
• wherein each of said stator lamination plates comprises:
• a flat annular plate of ferromagnetic material having a preselected outer diameter and a generally circular inner opening of a preselected inner diameter which forms the stator bore when like ones of said plates are stacked face-to-face with one another,
• said plate having a number of uniformly circumferentially spaced slots which project radially outwardly from the bore to an intermediate circumference of said plate to define teeth between the slots, said slots forming said stator slots when corresponding slot openings in the like plates are substantially aligned to communicate with one another and the plates are stacked,
• said annular plate including a tooth portion defined by said teeth between said intermediate circumference and said circular inner opening, and a yoke portion defined between said intermediate circumference and an outer periphery of said plate, and
• wherein each of said rotor lamination plates comprises a flat circular plate of ferromagnetic material having a number of equally circumferentially spaced closed slots extending radially in a region near the outer periphery of said plate,
• said slots being formed to contain conducting members which extend axially along the rotor when like ones of said plates are stacked face-to-face with corresponding slots in communication with one another;
• and
• wherein for a given ratio of said preselected inner diameter to said preselected outer diameter for said annular plate of each of said stator lamination plates, said teeth are sufficiently wide relative to the area of said slot openings so that the ratio of flux density in said tooth portion to flux density in said yoke portion in response to energization of the stator winding is optimized for the number of poles n in the operating configuration of said stator winding;
• and
• wherein the ratio of inner diameter to outer diameter of the annular plate forming said stator lamination plate is in the range of about 0.5025 to 0.504 for n equals 2.