16mm Diameter Ball Screw

Ball Screw Axial play and Preload

For standard Single Nut Ball Screws under normal conditions, a slight Axial play exists between the Screw Shaft and Nut. Consequently, when Axial loads act on Single Nut Ball Screw, total amount of Axial play and Elastic displacement due to Axial load becomes backlash. 

In order to prevent this backlash in Ball Screws, the Axial play can be reduced to a negative value. That is what we called Preload, which is the method of causing Elastic deformation to the Balls between the Screw Shaft and Nut in advance. 

Ball Screw Preload  effect

Preload is not only used for removing Axial play, it also has the effect of reducing the amount of Axial displacement due to Axial load, and improving the Rigidity in Ball Screws

Ball Screw Proper amount of Preload

Although the amount of Preload should be determined by the required Rigidity and the permissible amount of backlash, when setting Preload, there are some concerning issues as follows.

1. Increased Dynamic Drag Torque

2. Heat generation lowering of positioning accuracy due to the temperature rise

3. Shortened life

Therefore, it is adviseable to establish the amount of Preload at the lowest possible limits.