Ball screw is a transmission mechanical component in which the ball moves between the screw and the screw, converting the sliding contact of the traditional screw into rolling contact, and then converting the rotating movement of the ball in the screw into linear motion. Ball screw has high positioning accuracy, high life, low pollution and can do high-speed forward and reverse transmission and transformation transmission characteristics, because of the above characteristics, ball screw has become one of the important components of precision technology industry and precision machinery industry positioning and measurement system.