Structural Optimization Design Of EBA 2005-3 Ball Screw

Because of the advantages of high efficiency,high precision and small friction,ball screws are widely used in the servo feed system of CNC machine tools,with the continuous improvement of the cutting speed and feed rate of CNC machine tools,the requirements for the stiffness of ball screw feed system are also higher.As the weakest link in the feed system of CNC machine tools,the axial contact deformation and the axial contact stiffness of ball screw have great influence on the machining accuracy of the CNC machine tools.In order to improve the machining accuracy of CNC machine tools,in order to meet the requirements of high precision and surface quality of the parts processing,it is necessary to study the axial contact deformation and axial contact stiffness of the ball screw.In this paper,taking EBA 2005-3 type ball screw as the research object,the axial deformation and axial contact stiffness were studied,and the structural parameters which affect the axial contact stiffness are optimized,the main research contents including:1,First,this paper introduced the working principle,characteristics and classification of the ball screw pair,and the determination of the cycle mode,the pretightening mode and the pretightening force of the ball screw,and the structural parameters that affecting the axial contact stiffness of ball screws were analyzed;2,Basing on Hertz theory,the force and deformation of ball in ball screw were studied,the theoretical model of the axial contact deformation of ball screw was established,and on the basis of the above analysis,the condition of the ball is forced to close and the force is unequal,The theoretical model of axial contact deformation and axial contact stiffness of ball screw pair was deduced,and taking EBA 2005-3 ball screw as an example,the axial contact deformation and stiffness were solved;3,The mathematical optimization model was established based on the maximum axial contact stiffness of EBA2005-3 ball screw,the structural parameters of ball screw were taken as the design variables,and the constraints were added,Optimal calculation of mathematical model by MATLB optimization toolbox.4,The 3D assembly model of ball screw before and after optimization was established in Solidworks software,And the simplified 3D model was introduced into the ANSYS Workbench software,the stress and strain of the 3D model of ball screwbefore and after optimization were obtained,and the axial contact stiffness of ball screw was calculated,the results were compared with the theoretical calculation,verified the correctness of the optimization results.In this paper,the theoretical model was established to calculate the deformation and stiffness of ball screw,and the structural parameters that affected the axial contact stiffness of the ball screw were optimized,the stiffness of ball screw is improved,the stiffness of ball screw is optimized from2.476×108 N/m to 2.666×108 N/m,after optimization,the stiffness of ball screw is improved by 7.67% compared with the prior ball screw,the purpose of improving the stiffness of ball screw is achieved.