Semi-enclosed AC motor

A partially enclosed induction motor comprising:

• a cylindrical metal rotor assembly comprising an integral shaft and squirrel cage, said rotor assembly having axial cooling air passages extending end to end;
• a stator assembly comprising a generally cylindrical laminated iron core with axial slots for receiving straight sections of stator windings, said stator windings having coil end turns extending axially beyond the laminated core;
• a metal frame defining a housing having a generally cylindrical shape with bearing housings mounted to the frame at each axial end such that bearings in the bearing housing support the shaft of the rotor assembly and establish the rotation axis of the rotor assembly, the interior of the frame configured to closely embrace the laminated core and follows the contour of the coil end turns of the stator assembly;
• a seal between the stator assembly and the rotor assembly for hermetically sealing the rotor assembly from the stator assembly;
• heat conductive molding material filling gaps in the stator winding and the space between the stator assembly and the frame;
• a fan driven by the rotor shaft;
• and
• a shroud for directing the air expelled by the fan along the canister seal and through the rotor assembly.