A fractal model of normal dynamic parameters for fixed oily porous media joint interface in machine tools

Abstract

The joint interface plays a significant role in machine tools and other machineries. A novel type of joint which consists of oily porous material was proposed. The equivalent stiffness and damping of oily porous joint could be divided into solid and liquid parts, and the two parts are shunt connection. Theoretically, the stiffness and damping of solid part were established using Hertz contact and fractal theory, and the liquid counterpart was also deduced from the average flow of generalized Reynolds equation through a correlation parameter A r. It was concluded from simulation and calculation that the total equivalent stiffness of oily joint is increased with D and decreased with increased G. The experiment was carried out to compare the normal characteristics of porous material-steel oily joint with non-media steel-steel joint, and the result was that the joint which contains an oil film interlayer formed by porous and steel is superior to the joint with non-media formed by steel in stiffness and damping characteristics. In the case of the same preload, the former's stiffness is increased by about 30 %, and the damping is increased about five to six times meanwhile. © 2013 The Author(s).