Static And Dynamic Modeling And Analysis Of Linear Rolling Guideway

Linear rolling guideway is composed of rail, carriage, balls and other accessories, which exhibits complex mechanical behaviors under static and dynamic loads in supporting direction due to contact characteristics of the ball/surface rolling interface. The mechanical characteristics of the linear rolling guideway directly affect the machining accuracy and efficiency of CNC machine tools. It is significant for the structural design of the linear guideway and dynamic analysis of NC machine tools to gain the static and dynamic characteristics of the linear rolling guideway.Firstly, static modeling methods are proposed by using some theoretical and numerical approaches based on contact characteristics and the structure of the linear rolling guideway, and compared with experiment. The accurate static analytical modeling is proposed by using the Hertzian contact theory and corrected with experiment results. The precise finite element modeling is proposed considering contact characteristics, that is, using the component finite element model to replace the full finite element model, which is more efficient than the latter used widely. Load, preload and geometrical parameters have great influence on the stress of single ball and static characteristics of the system, which also are studied in this paper. The static modeling methods have great significance to propose the accurate dynamic modeling and analyze dynamic characteristics of the linear rolling guideway.Then, the analytical modeling and precise finite element modeling approaches are studied for the supporting direction dynamics of the linear rolling guideway. Contact characteristics of the linear rolling guideway are modeling with a series of springs whose stiffnesses are calculated by using static models. On the basis of considering the guideway structure and rolling balls distribution, the analytical model is created by using the Lagrange equiption and the precise finite element model is also created to explain the truth of modeling motheds. Effects of static load, preload and geometrical parameters on the inherent characteristics and effect of dynamic load on the vibration response are analyzed by using the analytical and precise finite element model. Finally, the obtained precise modeling method of the linear rolling guideway is applied to the dynamics analysis of a working table of a CNC machine tool and the rationality and necessity of considering the contact characteristic between balls and grooves are explained by comparing with the engineering approach and experiment results.