Verification of an equivalent circuit model for a helical motion induction motor

A helical-motion induction motor (HMIM) that can be used in a tandem arrangement of two units to form a direct-acting, two-degrees-of-freedom actuator capable of producing pure rotary motion, pure linear motion, or helical motion is described. It is shown that under appropriate definition of slip the Steinmetz equivalent circuit of an induction motor can be applied to this two-degrees-of-freedom machine. A procedure is developed for the determination of the equivalent circuit parameters, even though the magnetizing inductance is small for a typical secondary of conducting sleeve design. Experimental data recorded from an operational model of the HMIM show excellent agreement with values of thrust and torque predicted by the equivalent circuit