Research On The Influence Of Technological Parameters On The Life Of Machine Tool Spindle Bearing

Bearing is the key component that determine the stiffness and accuracy of the spindle system of a machine tool.When the CNC machine tool performance has been determined,the optimal combination of machining parameters can effectively improve the operating conditions of the spindle bearings,enhance the bearing life,and ensure the spindle runs stably for a longer time.With the machine tool spindle bearing as the research object,the research contents mainly consist the analysis of temperature characteristics and fatigue life of spindle bearing under different technological parameters and study on the optimization of the process parameters for the spindle bearing life.Firstly,the failure modes of the spindle bearing are analyzed,the influence of temperature and cutting force on the fatigue life of the bearing is discussed,and the fatigue life prediction method of the spindle bearing is given.According to the mechanical model of cutting force and process parameters,combined with the force analysis of machine tool s pindle,the relationship between process parameters and fatigue life of spindle bearing is established.Secondly,based on the theory of thermodynamics and heat transfer,the heat generation and heat transfer of the spindle bearing are analyzed.The finite element software ANSYS Workbench is used to simulate the temperature field of the spindle bearing,and the steady state temperature distribution of the spindle bearing under different working conditions is obtained.The temperature rise test of the spindle bearing is carried out on the self-built mechanical spindle bearing temperature characteristic test rig.According to the test results,the finite element model is verified.Thirdly,based on the nominal stress method,the finite element analys is software ANSYS Workbench is used to analyze the influence of different process parameters on the spindle bearing life.Based on the steady state thermal analysis of the bearing,taking into account the factors such as temperature and load,the fatigue life of the spindle bearing under thermal-stress coupling is obtained,and the finite element results are analyzed.Finally,.taking the three technological parameters of feed rate,cutting speed and cutting depth as the optimization variables,and taking cutting force,spindle torque,cutting power and processing conditions as constraints,based on the MAT LAB platform,genetic algorithm is used to optimize the solution.The optimization goal that the research establishes has the following three kinds: s ingle objective optimization considering the life of spindle bearing,multiobjective optimization considering the life of spindle bearing and cutting efficiency and multiobjective optimization of the life of spindle bearing and unit energyconsumption.The optimized results can meet the needs of the engineering application,and it has a certain guiding role for the technicians to select the processing parameters.