Abstract: During the assembly of rolling linear guide, preload is necessary of rolling linear guide to improve the machining accuracy and reduce the vibration. In order to study the influence of stiffness of linear rolling guide on its lubrication performance under preload condition, a stiffness model and lubrication analysis model considering preload were established based on LG-45 guide. Effects of ball diameter, groove curvature ratio and speed of the slider on the preloaded amount of the elasticity for steel-steel and steel-Si₃N₄ contact pair system were analyzed. The influence of the stiffness on the lubrication performance was discussed. Results show that, under the same conditions, elastic preload amount of steel-steel contact pair is higher than that of steel-Si₃N₄ ceramic contact pair. Effects of ball diameter and groove curvature ratio on the preloaded amountof the system elasticity aresmall, however, theinfluence of the slider velocity on the amount of preload is obvious. The film thickness and pressure will increase obviously with the increase of slider speed. As the curvature ratio increases, the contact ellipse ratio decreases, film thickness decreases, and the film pressure increases. When the diameter of the ball increases, the film thickness increases, but the film pressure decreases.

Key words: rolling linear guide, preload, lubrication, stiffness, preload amount of system elasticity