The structural diagram of the ball screw pair is shown in Figure 6, and the cross-sectional diagram of the screw, nut, and ball fit is shown in the following figure:
picture

Composition:
The ball screw pair consists of a screw, nut, steel ball, ball guide tube, etc. The screw and nut threads are single or multiple headed. The screw and nut thread raceways are single arc raceways or double arc raceways. Simple structure.
Loop method:
The screw and nut raceway form a ball circulation circuit through a ball guide tube, with each ball guide tube forming 1 5 or more turns of ball chain, the screw pair can be composed of multiple ball pipes to form multiple ball chains.
External dimensions:
Due to the deep groove of the ball nut and ball screw raceway, the ball is embedded inside the screw and nut, resulting in a small external size of the ball nut.
Motion stability
Due to the fact that the movement of the ball in the circulating ball chain of the screw pair needs to pass through the reverse mechanism, it is prone to impact and affect the smoothness of the screw pair.
transmission efficiency
Due to the high roughness and precision of the outer surface of the ball, the rolling friction coefficient is small, and the transmission efficiency is high, which can exceed 90%.
load bearing
Small specifications, small lead, small load capacity, large specifications, large lead, large load capacity.
Processing and assembly are relatively simple, and the precision of part processing and assembly is easy to ensure, therefore, it has high reliability.