Research On Contact Deformation And Dynamic Characteristics Of Ball Screw

High speed,high precision and high efficiency are the eternal theme of the development of CNC machine tools.Ball screw,as one of the most commonly used transmission device in the CNC machine tools,its performance plays a significant role in the transmission and positioning accuracy of the machine feed system.With the revitalization planning of national equipment manufacturing industry and the implementation of CNC machine development strategy,the rapid development of CNC machine tools puts forward higher requirements on the performance promoting and products upgrading of ball screw.At the same time,it's also promoting the development of ball screw to the direction of high speed,high precision and high performance.Meanwhile,the high-speed motion of ball screw will bring a series of problems such as temperature rise,wear aggravating,vibration and noise enlarging.Therefore,in order to improve the performance of ball screw and adapt the demand of high speed development,it is necessary to conduct an in-depth research on the performance of ball screw.Taking the ball screw for research object,which is based on the GSCK200 A CNC lathe ball screw feed system of the project “research on high speed and high precision CNC lathe”,the contact characteristics,rolling motion characteristics,friction characteristics and vibration characteristics of ball screw were studied in this paper.This dissertation contains following parts:Firstly,the contact characteristics and the influence of axial load and structure parameters on the axial elastic contact deformation and axial elastic contact stiffness of ball screw were analyzed on the Hertz contact theory.Secondly,,the motion characteristics and stress states of ball screw were analyzed,especially the reason of rolling motion characteristics and sliding motion characteristics of the ball in the raceway surface were analyzed by combining the dynamics principle.Thirdly,according to the motion characteristics of ball screw,combine with the tribology principle,the friction torque characteristics and its influencing factors of ball screw were analyzed.Finally,in order to obtain the natural vibration characteristics and response amplitude under external loads of ball screw,the modal parameters and harmonic response amplitude of the nut in different positions were analyzed and compared by using ANSYS Workbench software,which provides a theoretical basis for the structural optimization design of ball screw in the future.