General Electric Company

Thomas A Nondahl

Eike Richter

John Andrew Mallick

A rotor for a permanent magnet motor of the interior or embedded magnet type employs permanent magnet material in slots of two different widths in the rotor to bring the motor up to synchronous speed through hysteresis loss. During rotor rotation, the permanent magnet material in the thinner slots is driven completely about its hysteresis loop while the material in the wider slots experiences no polarity reversals.

Rotor for a line-start permanent-magnet motor

A homopolar inductor-alternator machine is constructed to have lower transient rectances by the incorporation of a current conducting ring concentric with the axis of the rotor and positioned on the rotor and/or the stator. The conducting ring helps prevent time varying fluxes from inducing eddy current flow in the high permeability rotor steel and unlaminated stator flux return path (back iron). The conducting ring acts upon the transient fluxes which occur in the DC flux path of the machine.

Growing community of inventors

Milwaukee, WI, United States of America

Thomas A Nondahl