Improved friction model for the roller LM guide considering mechanics analysis

In machining centers, investigating friction force in the linear motion (LM) guide is important in improving the positioning performance of the center. We analyzed the contact force and the contact pressure between the roller and raceway via the Palmgren formula and Hertzian contact theory, respectively. Based on Albrecht's friction model, an improvement model for calculating friction force was proposed which takes into consideration the bearing's geometrical parameters, the contact force and the changes in grease viscosity with pressure and temperature. The coefficients in the improved model were obtained from previously published experimental results. The improved model was verified by comparison to previous empirical equation results and the experimental results. The analysis showed that the improved model predicts the friction force more accurately compared to the previous model, and it will lay the theoretical foundation for predicting friction behavior in the linear motion guide.