Performance evaluation of different types of micro-textured hydrostatic spindles under the main influencing factors

Abstract

To improve the performance of a hydrostatic bearing, a method of constructing micro-textures on the inner surface of a bearing is proposed to increase the bearing capacity and reduce the friction coefficient. In this paper, the composite texture is innovatively proposed, and the theoretical models of hydrostatic radial bearings under four situations including non-texture, square, spherical, and composite textures are established. The effect of texture shapes and texture parameters on bearing performance is numerically studied and the influence level of various factors on bearing performance is evaluated innovatively using the cross-correlation analysis. The results show that the presence of a micro-texture can improve the bearing capacity and reduce the friction coefficient of the bearing compared with smooth surface bearings; the composite micro-texture increases the bearing capacity by about 9.5%, the stiffness increases by about 8.2%, and the friction coefficient is reduced by about 10.5%; there is an optimal micro-texture unit area ratio (between 30% and 40%) making the bearing capacity largest and the friction coefficient smallest; finally, the influence level of various factors on the bearing performance is evaluated. The relative depth of the texture has the greatest influence on it, followed by the number of textures, and finally the unit area ratio. The above results will provide a theoretical basis for the design of hydrostatic bearings with micro-textures.