The motion control mechanism comprises a rotor mounted rotating around an axis. The rotor has a first threaded part and a second threaded part separated by a central part placed in contact with a stator excited by an oscillator. A frame defines a first threaded part collaborating with the first threaded part of the rotor. The second threaded part of the rotor collaborates with an output shaft. Rotation of the rotor with respect to the frame results in movement of the output shaft along the axis. The oscillator comprises an oscillating mass excited by an angular actuator formed by piezoelectric actuators arranged around a star-shaped support. The oscillator is fitted inside the rotor configured in the form of a bell and comprising several stressed sectors.