| With China's economic development,the mechanical processing and manufacturing industry continues to progress as a pillar industry of the national economy.In recent years,high-speed,high-quality,low-consumption and other advantages in a high-speed processing technology have attracted increasing attention of people.As a core component of high-speed CNC machine tool,the spindle system realizes the "zero transmission" of the machine tool system and directly participates in the processing.The dynamic output performance under the condition directly affects the machining efficiency and precision.Therefore,it is very necessary to carry on the correlation analysis research to the electric spindle system.In this thesis,based on the basic scientific research project of the Ministry of Education,"Study on Coupling Mechanism and Stability of High-speed Spindle System of High-speed Spindle System",combined with relevant research at home and abroad,a series of BT40-4011-1500/12000-CX electric spindle system is taken as the study object.Based on the theory of rotor dynamics and thermodynamics,the thermo-mechanical coupling model of the motorized spindle system is established by using the finite element method,and the research and analysis are carried out.The main contents of this paper include the following parts:(1)Described in this paper,the research background and research significance,this paper expounds the main component of the electric spindle system and related structures,and the kinetics and thermodynamics of motorized spindle system modeling and thermal-mechanical coupling dynamic characteristics analysis of research status at home and abroad were summarized.(2)According to the relevant dimension parameters of the main parts of the research object,two dimensional and three dimensional models were established by using Autocad and Solidworks software.The components of the motorized spindle system were divided.Based on the relevant parameters of the bearings used in the motor spindle system,the expression of the bearing stiffness was solved.The dynamic model of the motorized spindle system was established by comparing three different joint modeling methods.The influence of bearing stiffness and three different joint modeling methods on the inherent characteristics of motorized spindle system were analyzed.Through the modal test,the simulation results were compared to solve the most realistic modeling approach.(3)Based on the theory of heat transfer,the heat generation,heat transfer and heat dissipation mechanism of the electric spindle system were studied.The heat generation of the system was calculated and the heat transfer coefficient of the internal and external system was taken as the evidence of the heat transfer boundary condition.The steady state temperature and transient temperature of the main components of the motorized spindle system were solved by Ansys software.The simulation results were verified by experiments.(4)By analyzing the dynamic and thermodynamic model of the spindle system and the mutual influence between them,the thermo-mechanical coupling model of the electric spindle system was established,taking the thermally induced preload force as a link.And the dynamic characteristics of the spindle system were analyzed at the same time.To sum up,this paper respectively establishes the dynamics and thermodynamics model of motorized spindle system in different ways through researching related properties of the main shaft system-the handle and the handle-tool integration,and designs the relevant test to verify the accuracy of the kinetic and thermodynamic model of the motorized spindle system.Thus the thermo-mechanical coupling model of the electric spindle system is established by taking the thermally induced preload force as a link,and analyzes its dynamic characteristics.The results will provide a foundation for the further study on high-speed and high-performance electric spindle unit and it has a certain academic significance and social economic effect. |
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