The Dynamic Simulation Of Linear Rolling Guide’s Contact Interface

Linear rolling guide, with its high-speed, high-precision, low-loss and wear-resisting,becomes a kind of new type of rolling support, gradually replacing slide guide, and is widelyused in CNC machine tools, industrial robots, precision electronic machinery and so on. As anirreplaceable functional component, the dynamic behavior of linear rolling guide will directlyaffect the accuracy of its subsidiary equipment. Because the linear rolling guide uses rollingbody to connect the guide and the slide block, which contact belongs to the point contact orline contact, so the dynamic behavior of linear rolling guide’s contact interface plays a keyrole on the overall performance, and is also one weak part. Therefore it is necessary to dodynamic analysis for the contact interface, and the crux is to establish an effective dynamicmodel.By using Hertz theory of classical contact mechanics and micro theory, the model of thecontact of the single cylinder and flat was analyzed, and from the view of the analyticalmethod, the expressions of the normal contact stiffness and the tangential contact stiffnesswere solved, which provided a theoretical basis for the identification of the parameters of thecontact interface. The method based on the frequency response function, to indentify theparameters of the contact interface, was introduced, and the model of the damping-springelement which nodes were not on the real contact interface and the model of theeight-nodes-element were analyzed. Then three dynamic models were mainly established. Thefirst was the vibration model of multi degrees of freedom which used eight spring elements.The second was the finite element model based on the first model. The third one was thedynamic model of the virtual material. In the first model, the Lagrange equation was used toestablish the system’s vibration differential equations, and the theoretical solutions of themodel’s natural frequencies and vibration modes were calculated. In the second model,through the finite element modal analysis, a more accurate result was got. In the third model,through the equivalent method, the mathematical models of the material properties includingYoung’s modulus, Poisson’s ratio and density, were established, which was helpful for theestablishment of the dynamic model.By the use of the Workbench platform which is the latest one of ANSYS, the dynamic simulations of the three models were separately carried out, and the first six order naturalfrequencies and corresponding vibration modes of those models were calculated. Thevibration modes of the several models are consistent, and those natural frequencies are in acertain error range. The model based on virtual material can take more factors influencingcontact stiffness, such as nonlinearity into account, and greatly simplifies the actual process ofmodeling, which is a convenient and effective dynamic model.