A Study on the Deflection of Rail by Bolt Tightening

볼트 체결에 의한 직선운동베어링 레일 변형에 관한 연구

The basic design of today s rolling linear guides with rails is outlined in a French patent from 1932, it was not until the early 1970s that linear guides were commercialized. Progress with the numerical control of machine tools led to higher speed and accuracy of machines that exposed limitations of conventional sliding guides in terms of durability and response capability. As a result, rolling guides, having better high-speed performance and greater compatibility with electronics, began to be used widely. This paper examined theoretically and experimentally the influence of rail bolt tightening on the motion accuracy of linear guides. The rail of a linear guide is tightened and fixed to the base component by bolts. Naturally, the rail is an elastic body and the compression force generated by tightening the volts causes its deflection. Compromising motion accuracy, the rail deforms wavily in a longitudinal direction corresponding to the bolt pitch. The relation between rail position and deflection(sinking) amount caused by bolt tightening was analyzed through FEM analysis in this paper.