Ball Screws
Low friction in ball screws yields high mechanical efficiency compared to alternatives. … Ball screws may also reduce or eliminate backlash common in lead screw and nut combinations. The balls may be preloaded so that there is no “wiggle” between the ball screw and ball nut. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. … The ball assembly acts as the nut while the threaded shaft is the screw.