How to guarantee ball screw precision

How to guarantee  ball screw preciison : Design factors that increase friction in a ball screw also increase torque and, in turn, affect positioning accuracy. The wedge effect created when balls are compressed between the ball screw nut and screw shaft is a potential source of friction. When rotating forward, the ball usually squeezes against the nut; when rotating reversely, the ball squeezes against the screw shaft. Since the sliding friction coefficient is much larger than the rolling friction coefficient, the wedge effect greatly increases the torque.

 

Torque caused by squeezing is particularly troublesome when the ball screw shaft vibrates within a fixed angle. This movement causes vibrational torques that are difficult to completely eliminate even with extremely precise parts.

 

Ball screws are usually used where precise positioning is required. High mechanical efficiency, low transmission torque and almost zero axial clearance make ball screws an important device in applications such as tool positioning and aircraft aileron drive. However, resistance and heat generated by continuous operation can cause significant friction and positioning errors.