Research On Dynamic Characteristics Technology Of Machining Center Double Ball Screw Feeding System

With the development of the CNC machine tool and having tend to high speed and accuracy and large load, double ball screw feeding system was widely used in high speed machining center. It can not only provide enough greater thrust and reduce the deformation of the machine tool vibration and guarantee the synchronous feeding of two ball screw drive, but the structure is balanced on both sides and the stability was great, and overcome the single ball screw of disadvantages, avoid the high cost of using a linear motor. However, the double ball screw of manufacturing structure is not completely symmetrical, and external disturbances of the two ball screw axis are different, so the force of the both sides are not remain completely pace, which led to torsion of the moving parts and the decrease of components precision and the consequences of damage to the machine tool. Therefore, the study of dynamic performance and thermal characteristic of double ball screw feeding system to improve the machining accuracy has important significance. This article main contents are as follows:1. The entity model of double ball screw feeding system is established. Based on the property of double ball screw feeding system, Relating to the design method of ball screw and calculating and selecting the components of this system, the Pro/E three-dimensional entity model of double ball screw feeding system was simplified. The model was laid the foundation for the subsequent simulation analysis.2. The dynamic performance testing system of double ball screw feeding system is designed. The dynamic performance testing system is established, the testing system consists of the two major components of mechanical system and testing system. The testing system was installed on the relevant sensors which using the LMS data acquisition system to collecting data and analyzing data.3. The dynamic characteristics analysis of double ball screw feeding system. Through the Lagrange equation in the transformation of generalized coordinates and provide theoretical basis for the dynamic characteristics of the finite element analysis. Using the ANSYS Workbench software was carried on the model analysis of double ball screw feeding system. By analyzing the contrast of the distance two ball screw shaft and the load on the dynamic characteristics of the feeding system, and the feeding system was optimized. 4. The thermal deformation analysis of double ball screw feeding system. Using on the finite element method to established the mathematical model of temperature field. Analyze the heat source of feeding system and calculate the calorific capacity, and make sure boundary conditions. Using the ANSYS Workbench software was contrasted and analyzed the two kinds of boundary conditions of the distribution of temperature field. Put forward the corresponding method to suppress double ball screw feeding system of the thermal deformation.About the double drive problems of ball screw feeding system, studing the double drive feeding system and designing dynamic performance testing system of double ball screw feeding system. Analysis of the dynamic characteristics and the characteristics of the thermal analysis. And put forward the corresponding improvement measures of double drive feeding system, laying a theoretical foundation for further study.