Thermal Error Modeling And Error Compensation Of High-speed Motorized Spindle

This dissertation makes the research of thermal analysis, thermal errormodeling and error compensation of the high-speed motorized spindle whichis used on a horizontal machining center made by Dalian Machine ToolGroup Co. Ltd. The object of the research is improving the thermalcharacteristics and decreasing the thermal error of the high-speed motorizedspindle to improve the processing accuracy of machine tools. The content ofthe dissertation mainly includes the following aspects:1. Based on the analysis of the structure of the high-speed motorizedspindle, the heat sources and the deformation caused by heat sources on thehigh-speed motorized spindle are analyzed. In the light of heat transfer theory,the calculating method of the heat generation is given, and the heat transfermechanism is analyzed.2. ANSYS is used on the high-speed motorized spindle’s thermalanalysis. First, the thermal load and the thermal boundary condition arecalculated by using experienced formulas. Second, ANSYS is used toproceed with the steady-state thermal field analysis, transient thermal fieldanalysis, and thermal deformation field analysis. Last, some measures areprovided to improve the thermal characteristics of the high-speed motorizedspindle according to the FEA results.3. Two different new methods are put forward to be used in the thermalerror modeling of the high-speed motorized spindle. The first one is thethermal error model on the basis of Factor Analysis and Bayesian Estimation,and the second one is the thermal error based on Natural Exponential. In thefirst model, the temperature measuring points are selected throughoptimization of Factor Analysis, then the thermal error of Factor Analysis is built and the unknown parameters in the model are estimated by usingBayesian Estimation. Last, experiments are executed to validate the model,and on the basic of high model precision, the temperature sensor amounts aregreatly decreased and both the precision and the robustness of the model areimproved. In the second model, the Natural Exponential thermal error underrandom revolving speed is built and two significant unknown parameters’calculating methods are given through the conclusions of experiments. Lastthe measuring experiment of the high-speed motorized spindle’s thermalerror under random revolving speed is executed to verify the model’saccuracy and robustness.4. The External Machine Zero Point Shift function of the FUNAC CNCsystem is explored and the real-time compensation system based onnetworking is developed. Through the geometric error compensationexperiment on the HDBS-63horizontal machining center and the thermalerror compensation experiment on the high-speed motorized spindle, thereal-time compensation system based on networking is validated to bereliable and practical.