Analysis of friction fluctuations mechanism of a preloaded roller linear motion guide based on a new 5-DOF dynamic stiffness model

Accurate modeling of friction in a roller linear motion guide (RLMG) bears significance in the positional deviation compensation of heavy-load mechanical systems. However, few models can predict the friction fluctuations performance of the RLMG. To address this problem, we propose a calculation method for calculating the time-varying friction based on a new five degree-of-freedom (5-DOF) dynamic stiffness model. In this approach, the rolling contact mechanism between the roller and raceway is analyzed. A new 5-DOF dynamic stiffness model is derived by considering the roller pitch shift, working phase and nonlinear friction damping, which is iteratively solved by four-order Runge-Kutta method under computing the initial value of each iteration. Based on this, the time-varying contact load of each roller under the periodic variations of roller-contact positions is calculated. Then, a time-varying friction calculation model is formulated considering the combined effect of the time-varying contact load, contact area and lubrication viscosity variations between the roller and raceway. The effects of the load magnitude, load orientation, roller pitch shift, preload and velocity on the 5-DOF real-time displacement, time-varying contact load and time-varying friction are discussed. The experimental results demonstrate the superiority of the proposed approach compared to the traditional model.

Automated summary

This paper proposes a calculation method for predicting the friction fluctuation performance of a roller linear motion guide (RLMG) based on a new five degree-of-freedom (5-DOF) dynamic stiffness model. The model takes into account factors such as roller pitch shift, working phase, and nonlinear friction damping to calculate the time-varying contact load and time-varying friction. Experimental results show that the proposed approach outperforms the traditional model.