Developing a Brushless Electric Motor with a Wide Adjustment Range of Mechanical Characteristics

A general concept is developed and a model of a new variant of a dc electric motor with windings on the rotor and stator made. The dc motor combines the advantages of brushless motors with permanent magnets on the rotor (with no brush-collector assembly), as well as collector electric motors with independent (parallel) excitation of electromagnets (a wide and smooth adjustment range of rotation frequency and torque of the shaft). The main innovation consists in transforming direct electric current into an alternating current with a frequency of 98.4 kHz for wireless power supplying the rotor winding of the electric motor. A schematic diagram, an electrical circuit and a working model, and the results of testing, as well as weight-and-size characteristics, are considered for a variant of such engine.