Electromagnetic machines such as electric motors, generators, and traction motors are useful for converting energy from one form to another. Such electromagnetic machines often include an element rotatable about an axis of rotation. The rotatable element or rotor may be coaxial with a static element or stator, and energy may be converted via relative rotation between the rotor and stator.
One type of electromagnetic machine, an alternating current induction motor, uses induced current flow to magnetize portions of the rotor during motor operation. More specifically, the rotor may be composed of a stack of steel laminations including teeth shaped to form poles and define slots therebetween. The poles may be separated by conductor bars disposed in the slots and electrically connected to shorting rings located at opposing ends of the lamination stack. Induced current may flow through the conductor bars which are disposed parallel to the axis of rotation along a periphery of the rotor. Each conductor bar may be electrically connected to every other conductor bar by the two shorting rings disposed at opposite ends of the rotor. The interaction of currents flowing in the conductor bars of the rotor winding and the stator's rotating magnetic field generates torque.