Theoretical Analysis of Damping Characteristics of Air-lubricated Slideways

Abstract

This Study analyzes the damping characteristics due to the squeezing effect of air-lubricated sljdeways.A transfer function, Which is represented by an equation of motion of the slideway and shows the relatjonshjp between displacement Of the SlideWay and the outer force, has a formula of the first order in the numerator and a formula of the third-ordor in the denominator.The results are applied on a slideway of an ultra precision machine tool, of whjch the mass of its table ISI500kg and static stiffness is 0.795kN/μm.The third-order denominator of the transfer funcljon js numerically resolved to two factors, a first order delay system and a second order vibration system.As a result, the revese Laplace transformation of the transfer function of the slideway for the step input is obtained, It is known that the Vibration of the airlubricated slideway is almost treated as the second order vibration system by its frequency response and Step response.A damping ratio equivalent to 0, 08 has been determined to be the typical value of the darnpjng force due to the squeezing effect.