Thermal Deformation Prediction Model Of High Speed Motorized Spindle

<China manufacturing 2025>to deploy manufacturing power strategy,also referred to as China Version "industrial 4.0" planning mentioned:CNC machine tools as the basis of manufacturing,was crucial for building of a powerful manufacturing country.High speed motorized spindle as the core components of CNC machine tools,its performance directly affected the machining efficiency and machining precision of CNC machine tool.High speed motorized spindle will inevitably produce temperature rise and thermal deformation in the operation process,thereby reducing the machining accuracy of machine tools.Therefore,it is an important method to improve the machining accuracy of the spindle to predict and compensate the thermal deformation of the motorized spindle.In this thesis,taking 100MD60Y4 motorized spindle as research object,using experimental and finite element modeling methods,the experimental data was combined with the finite element model.Based on the biogeography optimization algorithm,the heat transfer coefficient in the finite element model was optimized,the prediction model for the thermal deformation of the spindle was established,and the higher prediction accuracy was obtained.The main research works were as follows:Based on the basic theory of electric machinery and heat transfer,the heat source mechanism and heat transfer mechanism of motorized spindle were analyzed,and the basic equation of thermal expansion of motorized spindle was established;the coupling relationship between the air gap and the loss of the motorized spindle was analyzed.The thermal deformation test platform of motorized spindle was built,and the spindle temperature and thermal deformation data were collected simultaneously by the spindle dynamic rotation error analyzer.According to single factor test method,the influence of inlet pressure,oil supply time interval,single fuel supply,rotating speed and air gap on the temperature and thermal deformation of motorized spindle were experimentally investigated.Taking 100MD60Y4 motorized spindle as research object,the finite element model of motorized spindle loss was established,and the motor loss of motorized spindle was calculated;At the same time,the bearing loss of motorized spindle was calculated by empirical formula;Thermal deformation model of motorized spindle was established by COMSOL Multiphysics finite element software;Measuring the steady temperature data of the spindle by a thermal deformation test device,four test points were randomly selected.The objective function of the optimization of the heat transfer coefficient was established by using the difference between the simulation temperature and the test temperature.The heat transfer coefficient was optimized based on the biogeography optimization algorithm,the optimized heat transfer coefficient was taken as the boundary condition of the finite element model,and the thermal deformation prediction model of the motorized spindle was established.The prediction accuracy of the thermal deformation prediction model of motorized spindle was analyzed,and the temperature of the front bearing and the thermal deformation of the shaft were selected as the test points,the average absolute error between the simulation temperature and the test temperature of the spindle front bearing was 0.798,the variance was 1.601,and the standard deviation was 1.265;the average absolute error between the simulation thermal deformation and the experimental thermal deformation was 0.72,the variance was 1.319,and the standard deviation was 1.148.The optimized prediction model had a higher fitting degree with the experimental results,and the prediction accuracy of the model was high.Used the local sensitivity analysis to analyze the loss sensitivity of the heat source of thermal deformation model for motorized spindle:the spindle speed was 12000r/min,and the accurate value of spindle loss should be between +5%and +10%.In this thesis,a prediction model for thermal deformation of motorized spindle was established,which can realize the intelligent prediction of the thermal deformation of the motorized spindle and lay the foundation for the thermal error compensation of the motorized spindle.