Experimental Study And Model Establishment Of Coolant System Of The High-Speed Motorized Spindle

With the processing technology gradually moving toward precision,the machining accuracy of CNC machine tools is also increased.The motorized spindle was produced a lot of heat in the process of high speed operation.The heat generated by the motorized spindle is not easy to shed,and can lead to the thermal deformation of the motorized spindle.The manufacturing error caused by thermal deformation could reach 40%to 70%of the total error.Motorized spindle,as the core component of high speed machine tool,is the main heat source of CNC machine tools,which played an important role in the machining accuracy of machine tools.In order to improve the machining precision of CNC machine tool,the heat dissipation capacity of motorized spindle must be improved,and the coolant system of spindle must be studied to ensure the motorized spindle working at the optimum temperature.The research and application of coolant system can improve the heating problem of motorized spindle to a great extent,and play a very important role in improving the machining accuracy for further study.Firstly,the advantages and disadvantages of the coolant system of motorized spindle and its system structure were described in this thesis.The effect and significance of the coolant system on the cooling of the motorized spindle were introduced.Then the research ’status of the motorized spindle coolant system at home and abroad was described,the development and prospect of motorized spindle coolant system were introduced.Finally,the research progress on the motorized spirndle coolant system were summarized,and the gaps for this field at home and abroad was presented.Secondly,the heat source of the motorized spindle was analyzed,and the heating from the motor and the bearing were calculated.The heat transfer mechanism of the motorized spindle was analyzed,and the convective heat transfer of each component was mainly introduced,and the analysis and calculation were carried out.In this thesis,the basic principles of nonlinear regression analysis and multiple linear regression were discussed.The thesis also introduced several methods to be used in the regression analysis,which provided a reliable theoretical basis for the following model building.Thirdly,the finite element model of 170SD30-SY was built in ANSYS simulation software.The heat generation rate and cooling rate obtained based on the calculation were applied to the motorized spindle model,and the temperature distribution of the motorized spindle was obtained.Some measures to improve the temperature distribution of the motorized spindle were put forward according to the steady-state thermal distribution of the spindle.At last,the surface temperature of the motorized spindle was measured by using the automatic test system.The temperature of the motorized spindle could be obtained under different speed of the motorized spindle,the temperature and the flow rate of the cooling water.Through processing the data,a theoretical model could be found for the coolant system of motorized spindle by using the guidance of the theory of heat transfer.And the regression analysis and verification of the model were carried out.By comparing the calculated results with the simulation results,the accuracy of the model was verified.In this thesis,the coolant system of motorized spindle was studied,and the coolant system model was established.By comparing the calculated results with the simulation results,the accuracy of the model was verified.The research results could be used as a reference for the further study on how to improve the machining accuracy of the motorized spindle.