| The comprehensive quality indicators of advanced CNC machine tools and high-precision,high-performance and reliability products are important indicators for measuring the development level of the national high-end equipment manufacturing industry.The dynamic characteristics of the spindle system have an important influence on the overall dynamic performance of the CNC machine.This paper is from the National Natural Science Foundation of China "High-performance rolling bearing-spiral multi-body contact dynamics of spiral bevel gear system"(11462008).Based on the multi-body dynamics theory and the finite element method,a multi-body dynamics model of the horizontal spindle system of the milling machine considering the flexible deformation,dynamic contact and meshing transmission is established,and the dynamic characteristics of the spindle system are explored.The main research work is as follows:(1)Using the classical Hertz contact theory and parametric design method,the parametric multi-body dynamics simulation model of deep groove ball bearing,angular contact ball bearing,double row cylindrical roller bearing and spur gear meshing transmission is established.The dynamic characteristics of rolling bearing and gear meshing transmission under working conditions are calculated and analyzed.The feasibility of multi-body dynamics model is verified to some extent.Based on the parametric dynamic model of rolling bearing and gear meshing,the multi-body dynamics model of rolling bearing-multi-stage gear transmission is obtained,and the meshing transmission characteristics of rolling bearing-multi-stage gear are analyzed.The influence of the true contact effect of the rolling bearing,spur gear meshing drive and spline meshing drive on the dynamic characteristics of the multi-stage gear transmission system is calculated and analyzed.(2)Based on the theory of multi-body dynamics analysis,a dynamic tool-spindle-bearing component dynamics model considering the shank-spindle joint,the true multi-body contact of the rolling bearing,the flexible spindle and the flexible shank is established.Under the coupled excitation of the theoretical cutting force,torque and driving speed,the vibration characteristics such as radial vibration displacement of the flexible shank-spindle-bearing component and the dynamic characteristics of the rolling bearing system are analyzed.Based on the flexible shank-spindle-bearing rigid-flexible coupling multi-body dynamics model,considering the gear meshing contact transmission,the dynamic analysis of the shank-rolling bearing-horizontal spindle-spur gear system under the theoretical cutting force is discussed.The influence of rolling bearing and gear meshing transmission on the dynamic characteristics of the system.(3)Combining the rolling bearing-multi-stage gear transmission model and the tool holder-rolling bearing-horizontal spindle-spur gear model,the rigid-flexible multi-body contact dynamics model of the horizontal spindle system of milling machine is established,and the low-speed heavy load and high-speed light load are compared and analyzed.Dynamic characteristics and vibration response of the horizontal spindle system under working conditions.The parameter spindle system dynamics method proposed in this paper can predict the dynamic characteristics of the spindle system more accurately,and provides a reference for the research of digital design method of spindle system based on dynamic characteristics. |
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