Experimental and Theoretical Study of Hypocycloidal Motors with Two-Harmonic Field Windings

Hypocycloidal motors are torque motors which represent an intermediate class between high velocity motors with a mechanical reducer and motors designed for normal work at low speed. In this paper, anew form of hypo cycloidal motors is presented, in which a simple three-phase stator winding, producing a two-harmonic field in the air gap, allows a notably simpler construction, and a considerable improvement of performance. The theoryof the new motor in its synchronous version is developed, and its transient performance is simulated, showing that the motor is able to start with large mechanical loads inserted, and to reach the synchronous speed with avery small angular error with respect to an ideal step starting. Finally, experimental results are described, which confirm theoretical previsions.