Abstract: A polyphase electrical machine having one or more stators, each stator having a plurality of phase windings, each phase winding having a plurality of concentric coils. One or more concentric coils of a phase winding are interspersed with one or more concentric coils of at least another phase winding to reduce undesirable harmonics and parasitic losses in the electrical machine. For single phase electrical machines, harmonic content and parasitic losses may be reduced by locating nested coils such that successive nested coils among a plurality of nested coils may have a span difference of greater than two stator slots.

Abstract: A polyphase electrical machine having one or more stators, each stator having a plurality of phase windings, each phase winding having a plurality of concentric coils. One or more concentric coils of a phase winding are interspersed with one or more concentric coils of at least another phase winding to reduce undesirable harmonics and parasitic losses in the electrical machine. For single phase electrical machines, harmonic content and parasitic losses may be reduced by locating nested coils such that successive nested coils among a plurality of nested coils may have a span difference of greater than two stator slots.

Abstract: A cooling gas ventilation circuit is provided for an endwinding of a rotary machine having a rotor and a plurality of coils seated in radial slots provided in the rotor. The coils each comprise a plurality of radially stacked turns, the coils extending beyond a pole face of the rotor to form an endwinding with longitudinal cavities between the coils. A substantially cylindrical baffle ring covers the radially innermost turns of the plurality of coils in the endwinding, and has a plurality of holes therein aligned with at least one of the longitudinal cavities between the coils.

Abstract: A cooling gas ventilation circuit for an endwinding of a rotary machine having a rotor and a plurality of coils seated in radial slots provided in the rotor, the coils each comprising a plurality of radially stacked turns, the turns having radial passages therein, the coils extending beyond a pole face of the rotor to form an endwinding; a substantially cylindrical baffle ring covering radially innermost turns of the plurality of coils in the endwinding, the baffle ring having a plurality of holes therein aligned with the radial passages; and wherein the radial passages communicate with cavities between the coils in the endwinding.

Abstract: The dynamoelectric machine has endwindings 24 including a plurality of superposed conductor bars 22 and adjacent end turns 20. Rabbets 32 are formed along the undersides of the adjoining conductor bars and end turns to receive gussets 30 for reinforcing the joints therebetween. One or more of the conductor bars and end turns have cooling passages 36, 38 with ports 40, 42 opening to one side of the joint at locations short of the joint. A cooling block 48 is disposed on one side of the joint extending between the superposed conductor bars and superposed adjacent end turns and spaced from the joint to define a chamber 60 in communication through the ports with the passages for passing cooling gas therethrough in heat exchange relation to the joint assembly.

Abstract: The dynamoelectric machine has endwindings including a plurality of superposed conductor bars 22 and adjacent end turns 20. Rabbets 32 are formed along the undersides of the adjoining conductor bars and end turns to receive portions 34 of gussets 30, remaining portions 35 of the gussets projecting to one side of the joint. The conductor bars and end turns have grooves 38, 36 forming cooling passages with ports 42, 40 opening to one side of the joint short of the joint. The gusset 30 has a barrier 44 spaced from the joint and forms with the ports a cooling channel 46 between the ports for transporting cooling gas between the cooling gas channels of the conductor bars and end turns.

Abstract: Disclosed is a rotor body for an electric machine having slots for windings and slot keys with wedges for retaining the windings in the slots. The slot keys contain elongated spring strips underlying an amortisseur, in turn, underlying the wedges in the slot keys. The spring strips bias the amortisseur and wedges radially outwardly. Thus, the wedges lie in sufficient, low-resistance, efficient electrical contact with the rotor body at start-up and during low rotor speeds to prevent arcing and localized heating along the interfaces of the rotor parts otherwise resultant from induced surface currents at start-up and low rotor speeds. At the rotor ends, the spring strips bias the amortisseur ends radially outwardly into efficient electrical contact with retaining rings at opposite ends of the rotor body.

Abstract: A tool for applying slot wedges having a main arm, a pair of pivotally mounted dogs for engagement in the slot key and straddling the external surface of the slot key, respectively, whereby the tool may be fixed in axial position along the slot key by pressure on the main arm. A second pivotal arm carries a wedge-engaging head whereby the lever is fixed in the slot and the second arm drives the wedge longitudinally into axial position in the slot key.