Analysis Method Of Thermal Balance Characteristics Of Precision Spindle Unit

Precision spindle unit,as a key component of high-speed machine tool,is an important research object in the development of high-speed industry.Under high-speed operation,its internal heat generation results in thermal deformation of spindle structure,which seriously affects the processing accuracy of machine tools.Therefore,it is great significance to analyze and study the thermal balance characteristics of precision spindle unit.In this paper,the typical precision spindle structure is taken as the research object.The Thermal-Fluid-Solid coupling simulation model of precision spindle unit is built by Finite Element Method,and by the thermal load of the model is optimized.A high-precision simulation model of multi-physical field coupling for thermal balance analysis and designs of precision spindle unit is established.Firstly,the heat generation/heat transfer source of precision spindle unit is analyzed and based on empirical formula,the relevant modeling method is obtained,which is used as the thermal load condition of Thermal-Fluid-solid coupling simulation model of precision spindle unit based on ANSYS Workbench and Fluent UDF functions.The experimental platform of thermal characteristics of precision spindle unit,which integrates monitoring and active control,is further built.The temperature control system of precision spindle unit and the post-processing tool of the results are studied,and the closed-loop temperature control which integrates acquisition and active control is further realized.Secondly,a multi-parameter and single-objective non-linear optimization analysis model for thermal characteristics of precision spindle unit is proposed.In order to solve the problem that the same type of time-varying design variables lead to large scale of design variables in multi-parameter optimization design,a step-by-step optimization analysis model based on time interval is proposed to improve convergence efficiency.Further,the Python secondary development interface based on Ansys Workbench is used to complete the thermal load optimization design software of precision spindle supporting the step-by-step optimization design model.By optimizing the thermal load value of the simulation model,the data collected by the experimental platform are basically consistent with the data collected by the simulation results.Finally,the thermal load value of precision spindle unit is optimized,so that the transient simulation results at each time point of the spindle operation process are basically consistent with the temperature of the experimental data at the key acquisition points.Based on the simulation results,the time-varying heat generation and heat dissipation of the precision spindle unit are analyzed,and the rule of the net inflow heat of the precision spindle unit with the change of time is finally obtained.Considering the influence of fluid turbulence on the precision spindle unit,a high-precision simulation model of Thermal-Fluid-Solid coupling is established in this paper.This method greatly improves the feasibility of analyzing the internal temperature field characteristics of the precision spindle unit during its operation,and provides high-precision time-varying data for subsequent thermal analysis and thermal error suppression research.This method greatly improves the feasibility of thermal balance design of precision spindle unit,and provides precise time-varying data of temperature field of precision spindle unit for subsequent thermal characteristic analysis and thermal error suppression research.