Rotor geometry for reduction of torque ripple in a wound field machine

摘要

An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator.

主权项

1. An electric machine comprising:
a rotor configured to be rotatable within a stator; a first tooth disposed along an outer perimeter of the rotor, the first tooth defining a first outer edge extending between a first tooth base and a first tooth tip; a second tooth disposed along the outer perimeter of the rotor, the second tooth defining a second outer edge extending between a second tooth base and a second tooth tip; a first slot provided in the rotor and at least partially defined by the first and the second tooth; wherein an arc radius from an origin to the outer perimeter of the rotor varies along the first outer edge, thereby creating a first non-uniform gap between the rotor and the stator; wherein the arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge, thereby creating a second non-uniform gap between the rotor and the stator; a first slot central axis defined by the first slot; and a first slot opening defined by a space between the first and the second tooth tip and having a first slot opening central axis, the first slot opening central axis being offset from the first slot central axis.