Direct current motor unit without commutator

An electro-mechanical motor unit formed of an electronic power supply device for driving a D.C. commutatorless motor, comprising:

• a stator having a plurality of driving coils for supplying power to said motor for generating an axial magnetic flux, said coils being housed in respective ferrite half-pots of axial generatrices;
• at least one thin-wire control coil magnetically interconnected with said plurality of driving coils and adapted for generating a variable control signal in response to operational speed of said motor;
• a rotor having an axially-magnetized ring;
• at least one magnetized positioning stud on said stator in a location thereof such as to bring said rotor at rest in a precise angular position relative to said stator;
• a motive torque output shaft adjacent to but spaced from said rotor ring;
• rotor speed responsive, centrifugal clutch means interposed between said rotor and said shaft for mechanically interconnecting the same only subsequent to the starting of said rotor;
• a power transistor for generating pulses of current to drive said driving coils and having a collector electrode connected to said plurality of driving coils, a base electrode controlled by said at least one control coil through a resistor;
• and
• a Zener diode having a nominal breakdown voltage lower than the breakdown voltage of said power transistor and connected between said base and collector electrodes.