Ball screws for high speed drive

摘要

In recent years, a remarkable increase in maximum speed has been achieved for linear motion mechanisms driven by a ball screw. This is evident in the availability of machines on the market of which maximum speed exceeds 100m/mm. The primary focus of this article is to describe one of the techniques we developed to increase operational speed of ball screws. This technique has made it possible to rotate a ball nut twice or three times faster than before with low vibration by implementing a vibration damper that enables operation of a ball screw exceeding its critical speed. We will also describe how we have increased allowable rotational speed (d{sub}mn) by enhancing strength of ball re-circulation parts, a technique to lower audible noise, and practical applications according to usage of ball screws that have medium, high, or ultra-high helix.