Slide flow distributor (100) comprising a motor (1) moving directly a spool (2) by means of a rod (8) of the motor, a charge chamber (3) of the working fluid, in central position, in fluid communication with two discharge branches (4, 5) and two delivery branches (6, 7) and characterized in that from the portion of the spool (2) proximal to the motor (I) it is provided a pneumatic servo-actuator (9) generating a force in the same direction and development of the axial force of the motor (I), with the result that the spool (2) is accelerated in a predetermined direction, said pneumatic servo-actuator comprising a profiled body (52), a plurality of balls (50) and corresponding elastic means (5 1) which press said plurality of balls (50) on the side surface of the profiled body (52).