A novel design method to reduce the impact between ball and re-circulating mechanism in ball screws

In high-speed/high-precision ball screw transmitting systems, the re-circulating mechanism of ball screws is used for providing the path for steel balls rolling in screw grooves generally. Because the rotating speed of the driven shaft in the mechanism has become higher and higher, forces caused by the impact activity between the steel ball and re-circulating mechanism has resulted in a series of troublesome problems, such as violent vibration, strong noise, and damage to the recirculating mechanism after some significant service times, etc. In order to reduce the impact, a novel method using elastic joint between re-circulating mechanism and nut is proposed and the influence of joint rigidity on impact force is discussed. The conclusion is made that the impact force using rigid joint is always higher than that using elastic joint, and the influence degree of joint rigidity on the impact force is affected by the mass radio of steel ball and re-circulating mechanism. The experimental results show that using elastic joint between re-circulating mechanism and nut can reduce the impact force effectively.