考虑油膜阻力的直线滚动导轨副摩擦力建模与试验

为了准确预测直线滚动导轨副的摩擦力大小及受影响因素,本文考虑导轨副的流体润滑状态,基于Hertz接触理论研究了直线导轨副摩擦力受滚珠接触角和预紧力的影响规律.基于接触理论建立了直线导轨滑块的受垂直载荷的静力学平衡方程.利用Hertz接触理论分析直线滚动导轨受外力时各列滚珠接触力的变化情况,并结合对临界载荷的分析,建立了随外载荷变化的考虑润滑油膜阻力的直线滚动导轨副摩擦力模型.以国产某型号直线滚动导轨副为研究对象,对所建立的受载摩擦力模型进行试验验证.通过试验数据与理论数据的分析和对比,验证了润滑油膜阻力、接触角和预紧力等因素对直线导轨副摩擦力的影响规律.研究表明,直线滚动导轨副摩擦力在润滑条件下,受接触角变化和预紧力退化的影响呈现有规律的变化.

Modeling and experimentation of the friction force of linear rolling guide pair considering oil film resistance

For an accurate prediction of the friction experienced by the linear rolling guide and the factors affecting it, the fluid lubrication state of the rail was considered,and the effect of the friction of the linear guide on the ball contact angle and preload was studied based on the Hertz contact theory. Based on the Hertz contact theory, the static equations and the ball-raceway contact me-chanics equations of the linear rolling guide were established for vertical loading. Using the Hertz contact theory,changes in the ball contact force of the linear rolling guide were analyzed. Combining the analysis of the critical load and the oil film obstruction between the balls and the rail,a friction model was established for studying the effect of the external load. Experiments were carried out on a domestic model of the linear rolling guide to validate the developed friction model. Through the analysis and comparison of the experi-mental and theoretical data,the influence of the resistance of the lubricating oil film,the contact angle,and the preload on the friction of the linear guide were verified. The results show that the friction of the linear rolling guide,under the condition of lubrication,is af-fected by the contact angle and the preload force.