Thermal Deformation Analysis And Structural Optimization Of Five-Axis Linked Gantry Machining Center

The high-speed and high-precision machining center is becoming one of the most important part in the machinery manufacturing industry with the development of modern society.However,the machine tool parts have a thermal deformation because of the internal heat source and the external heat source.Therefore,the thermal deformation of the machine tool parts has a certain impact on the machining accuracy,which has become an important factor affecting the accuracy of the high-speed and high-precision machining centers.Therefore,it is quite a significant way to improve the production precision by analyzing and improving the mechanism with trend of the temperature field.Based on the project of 'Green Design Technology and Application Research of Large-scale Five-axis High-speed Precision Gantry Machining Center',the paper takes the five-axis linkage gantry machining center for research object by combing the three-dimensional modeling software and finite element simulation software.Finally,effective analysis of the ball screw feed system and column rails of the thermal characteristics of the current research topics are as follows:1.The background and significance of the five-axis gantry machining center are analyzed.At the same time,the parts with high temperature rise are discussed to determine the research object for Z-ball screw feed system and X-direction column guide.Finally,the finite element model is established.2.According to the theory of heat transfer,the thermal differential equation of the model is established.What's more,the heat generation coefficient of the ball screw nut,the heat generation rate of the bearing system,the heat flux density of the model part and the convective boundary condition are analyzed.Based on these data,the steady-state temperature field of the ball screw feed system is analyzed by the finite element model.The axial and radial deformation of the screw is obtained by thermal-structural coupling analysis.According to the deformation of the proposed prestressing force,the topology optimization for bearing seats is finished.3.Considering the kinematic pair and the heat source of the power source,the steady-state thermal characteristics of the X-direction column guide rail are analyzed.At the same time,the temperature characteristics such as the temperature rise characteristic and the temperature field distribution are obtained,including the variation law.According to the force and the constraint,the impacts on processing are studied.What's more,the optimal solution of heat dissipation is determined by studying the feed rate,the cooling water flow and the convective heat transfer coefficient.4.Through the experiment of thermal state,the model is used to draw the temperature rise curve.The experimental results are compared with the finite element simulation results to research for the transient temperature rise and determine the accuracy of the model.