Abstract: A rotor comprises laminations with a plurality of rotor bar slots with an asymmetric arrangement about the rotor. The laminations also have magnet slots equiangularly spaced about the rotor. The magnet slots extend near to the rotor outer diameter and have permanent magnets disposed in the magnet slots creating magnetic poles. The magnet slots may be formed longer than the permanent magnets disposed in the magnets slots and define one or more magnet slot apertures. The permanent magnets define a number of poles and a pole pitch. The rotor bar slots are spaced from adjacent magnet slots by a distance that is at least 4% of the pole pitch. Conductive material is disposed in the rotor bar slots, and in some embodiments, may be disposed in the magnet slot apertures.

Abstract: A rotor comprises laminations with a plurality of rotor bar slots with an asymmetric arrangement about the rotor. The laminations also have magnet slots equiangularly spaced about the rotor. The magnet slots extend near to the rotor outer diameter and have permanent magnets disposed therein creating magnetic poles. The magnet slots may be formed longer than the permanent magnets disposed therein and define one or more magnet slot apertures. The permanent magnets define a number of poles and a pole pitch. The rotor bar slots are spaced from adjacent magnet slots by a distance that is at least 4% of the pole pitch. Conductive material is disposed in the rotor bar slots, and in some embodiments, may be disposed in the magnet slot apertures.

Abstract: According to one embodiment, the present invention provides a motor having a stator core disposed in a motor frame. The stator core is formed of a plurality of substantially identical laminations. Each lamination of the stator core comprises at least one recessed section, which, in cooperation with the frame, defines an incremental segment of closed passageway for routing a fluid along a perimetric surface of the stator core. Accordingly, the closed passageway provides a mechanism by which the outer regions of the stator core may be more effectively cooled. Furthermore, the laminations of the stator core may be oriented at varied orientations with respect to one another to form a labyrinthine path along the surface of the stator core through which coolant is routed.

Abstract: The present invention relates generally to dissipation of shaft charge. According to an exemplary embodiment, the present invention provides a charge-dissipating device that includes a dissipation member disposed in an explosion-proof enclosure. When mounted to a rotatable shaft of an electric motor, for example, the dissipation member is configured to generally abut against the rotatable shaft. The dissipation member dissipates shaft-charge developed in the rotatable shaft during operation of the motor. By dissipating shaft charge, the likelihood of arcing and/or bearing current (Ib) occurrences are reduced or eliminated. In accordance with another exemplary embodiment, a transmission member is configured to impart a voltage signal onto the shaft.