BALL SCREW

Ball screw actuator (1) for an electromechanical brake system, wherein a rotational movement of an electric actuator, which rotates in a brake rotational direction to actuate a brake of the electromechanical brake system and rotates in a release rotational direction to relieve the brake, is transferable to the ball screw actuator (1) via a reduction gear and is convertible by means of the ball screw actuator (1) into a translational movement to actuate the brake in a brake direction (B) and to relieve the brake in a release direction (E), which ball screw actuator (1) comprises a ball nut (3) and a threaded spindle (5), which together form a helically wound ball channel (7) with balls rolling therein, wherein the ball nut (3) is designed to receive two or more dowel pins (13), wherein the rotational movement is transferable from the reduction gear to the ball nut (3) by means of the dowel pins (13) and is convertible into a translational movement of the threaded spindle (5) by means of the balls.