CONTACT MODELING AND ANALYTICAL SOLUTION OF CONTACT STIFFNESS BY HERTZ THEORY FOR THE LINEAR ROLLING GUIDE SYSTEM

The linear rolling guide is an important function part of CNC machine tools. Analytical modeling is an efficient method to analyze the effect of characteristic parameters of a linear guide on its mechanical properties. In this investigation, the contact modeling and analytical solution of contact stiffness for the linear guide system is completed based on Hertz contact theory. First, the analytical formula of the contact stiffness is derived for the rolling interface between the single ball and groove. Then, the deformation relationship between carriage and guide is analyzed systematically and the normal contact modeling of the linear rolling guide system is set up. At last, taking the NSK linear guides as objects, the contact stiffness of the single rolling interface and the whole guide system are solved for four kinds of different preload levers, and the curves of load-elastic deformation and stiffness-elastic deformation are drawn respectively. In addition, the effects of loads and preloads on the contact stiffness of the guide system are also analyzed based on the proposed model.