Machine Sliding Rail Joint Surface Dynamic Parameters Identification Test

High-end CNC machine tools are the base of modernization of manufacturing industry. Establishing accurate dynamic model of the mechanical structure has become major factor which promote the design of High-end CNC machine tools. Joint is an important part of dynamic modeling of the mechanical structure. Studies have shown that elasticity and damping of machine tool's joints is greater than Mechanical structure themselves'. In this paper, identification of dynamic characteristic parameters of the sliding joints is studied. It provides the dynamic model of sliding joints with the dynamic characteristic parameters. This paper analyses the main factors which influencing the dynamic performance of sliding guide and gives different treatments to different factors. The factors'content and method studied is also given.This paper made an analysis of dynamics on slider with witch the sliding joints are simulated with spring-damping, and drives a model of the characteristic parameters of signal degree of freedom system which based on relative displacement of vibration. Identification method of sliding joint's dynamic characteristic parameters per unit area and the inspection stand for identification rate are present. Based on the identification model, the test scheme is designed, the test equipment and the test platform are developed. According to the requirements of the slider's dynamic characters, the concept of relative dynamic flexibility coefficient and its calculation method was proposed, and after the optimization design of the slider with the relative dynamic flexibility coefficient as the object function, the slider meets the requirements of design.A brief introduction of the steps that identification of dynamic characters'parameters of sliding joints with single degree of freedom is given. A certain number of dynamic characteristic parameters of typical sliding joint were obtained through the experimental modal analysis. These parameters were an important part of the database of the dynamic characteristics of machine tools'joint. With the analysis of the identification result, summed up the law of pressure, lubricant oil and relative velocity of sliding joints influence on the dynamic stiffness and damping of sliding joint, and analyses the reason for forming these laws with micro-contact theory.