SKF SD 8x2,5R 202/255 G9 Z drawing no. S440023 Ball screw

Ball and roller screws convert rotary motion into linear motion and vice versa. A traditional screw consists of a steel shaft with a trapezoidal thread and a bronze, metal, or plastic nut. In contrast, linear screws are equipped with rolling elements (balls or rollers) that transmit power between the nut and the screw shaft. This rolling motion minimizes friction between the nut and the shaft. Due to the high efficiency of this technology, ball and roller screws are not self-locking. Therefore, some applications require a brake to prevent the carriage from drifting under its own weight.