Abstract: An alternating current (AC) motor system includes an AC motor having a rotor and a stator with the rotor having a plurality of air passes for passing cooling air and the stator having end windings extending from each end. An air deflector is coupled to one end of the rotor and has a generally curved configuration for directing cooling air exiting the air passages into a generally radial flow direction and onto the stator end windings. The stator end windings comprise turns of a plurality of electrical conductors forming the stator winding circuits which are wound to form a plurality of phase windings. Controllable switches are connected to the winding circuits for coupling the phase windings into either a parallel or series circuit arrangement. The system is responsive to motor speed and operating state for selectively switching the windings between the series and parallel electrical circuit arrangements.

Abstract: A brush cooling system for a direct current electric motor of the type having a housing with an air inlet at one end for admitting forced cooling air to the motor and brushes located at an end of the motor distal from the air inlet, includes at least one air duct extending from the air inlet end of the motor through a space defined by adjacent stator windings of the motor and terminating at about an end of the windings opposite the air inlet end. A convergent nozzle is releasably connected to the terminating end of the air duct and extends from the air duct to an area generally adjacent the motor brushes for directing cooling air from the duct onto the brushes. Field coils of the stator windings are separated by air spaces and the air ducts extend through the air spaces between field coils. Each air space not including an air duct is substantially blocked by a baffle inserted in the space for inhibiting air flow through the air space.

Abstract: The trailing edge of a carbon brush for commutating electric machines has a notch flanked by an ear on either side. The brush can include one or more wafers. The angular thickness of the trailing brush wafer at the notch is such that the brush does not touch more than n commutator contacts at a time. However, the brush wafer is thick enough at the ears to touch n+1commutator contacts at a time. The relatively high resistance of the ears improves commutation.

Abstract: Method and apparatus for optimizing power delivered by a prime mover-driven electric power alternator to an adjustable speed electric traction motor during high speed operation. The alternator is suitably controlled to deliver constant power if its output voltage does not exceed a first predetermined magnitude corresponding to a "corner point" speed of the motor and to limit the voltage magnitude when motor speed exceeds this corner point, thereby preventing excitation current from exceeding the maximum continuous field current rating of the alternator. As motor speed increases above corner point speed, less power is delivered to the motor, but the power reduction is minimized by increasing the voltage limit above the first predetermined magnitude. The amount of voltage limit increases, up to a predetermined maximum amount, is proportional to the amount load current in the motor decreases below its magnitude when motor speed equals corner point speed.