Research On Remaining Life Prediction And Remanufacturing Evaluation Of The Retired Machine Tool'spindle

There are more than 8 million machine tools in China,and more than 60% of the machine tools have a service life of more than 10 years.In the next few years,these machine tools may face idleness,scrap,functional elimination or technical elimination,the remanufacturing machine tools will become a large-scale recycling potential resources.Therefore,the remanufacturing industry will usher in an important opportunity for development.At present,remanufacturing technology research mainly focuses on the remaining life prediction and remanufacturability research of the aerospace,auto parts,engineering machinery and other mechanical equipment.Research on the spindle components of retired machine tools is rarely seen.Based on the fatigue damage theory of the retired machine tool spindle components,a new method for predicting the remaining life is established.And after the judgment of the remaining life of the component,a set of remanufacturability evaluation process is established,and the quantitative judgment basis of each parameter is given,so that it is more accurate to judge whether the component has remanufacturability before remanufacturing.This method is not only suitable for judging whether the retired machine tool spindle components can be remanufactured,but also providing a way of thinking for the remanufacturing of high value-added components of decommissioned machine tools.We cannot judge from the appearance whether it can be remanufactured.At present,the evaluation method of remanufacturability of the retired machine tools is still based on qualitative evaluation and expert judgment of mechanical equipment,moreover,it focuses on macro analysis,and the evaluation of remanufacturability of high value mechanical parts is seldom discussed.In addition,the manufacturable evaluation of the parts(such as the spindle of a machine tool)can be evaluated by the its failure feature,therefore it is necessary to createa scientific and reasonable quantitative remanufacturing evaluation method.After judging the remaining life of the machine tool spindle's component,it is judged that it has remanufacturability.It provides a new idea for the study of other high value components in the machine tool.This article main research content is as follows:1)On the basis of fatigue damage accumulation theory,combined with the feature of retired spindle component of machine tool remanufacturing service load,and put forward a kind of remanufacturing spindle component of machine tool residual life prediction theoretical numerical model.It will reveal the essence of the change in the life of spare parts.First extend the existing life prediction methods of materials or specimens to other key parts of the equipment.second establish the geometric precision modeling method for the spindle parts of the machine tool with multi-failure characteristics.It provides a theoretical method for the safety performance of key parts for remanufacturing machine tools,which based on the self-adaptive meshing method of spindle component of remanufacturing machine tools with compute domain virtual programming and the feature load method for the main shaft component of remanufacturing machine tools with the numerical analysis.2)On the basis of finite element theory,elastic-plastic mechanics,and the principle of calculus,Abaqus simulation technology is used to analyze and discuss the characteristics of the service of the main shaft parts of the machine tool such as residual stress load,high speed centrifugal stress load,equivalent stress load,etc.Based on analysis and simulation results,we can evaluate the static strength of the active component of the main shaft,and it also provides a basis for the fitting of load spectrum with the life prediction of remanufacturing key parts.If we input amplitude to fatigue analysis software,we can get the residual life value of the spindle.Therefore,the remaining life of the remanufactured spindle is analyzed according to the load change.3)Since the decommissioned machine tool spindle is a small sample,for the small sample problem,the Monte carlo method was used to sample and then the sample was resampled by the Bootstrap method to solve the problem of sample size.The prior distribution of Bayesian distribution was used to solve the accuracy problem of Weibull distribution shape parameters.The Bayesian posterior distribution method and the least square method weighted value are used to improve the efficiency of data utilization.It is established by the method for estimating the exact values of the shape parameters and position parameters of the Weibull distribution.The residual life prediction rules of the small sample parts are revealed and proposed Sample Capacity of Spindle Parts Remaining Life Prediction Problem.Thus,the residual life of the spindle can beforecasted.This method is consistent with the remaining service life results of the spindle components by finite element analysis.4)The membership theory of fuzzy mathematics start from the failure characteristics of spindle parts of a machine tool,put forward some key technical indicators,upgrade the qualitative evaluation of the reconstructive nature of the main axis of the decommissioned machine tool to a quantitative evaluation and make a general assessment of the subject to various factors.For the retirement of machine tool spindle parts to produce qualitative evaluation,we can establish a manufacturable evaluation model for the main shaft parts of decommissioned machine tools.5)Study the available remanufacturability of spindle components of decommissioned machine toolsand construct a remanufacturabe evaluation system for the spindle parts of a decommissioned machine tool.To obtain its quantification value through the Analytic Hierarchy Process(AHP)to determine the weight value of each evaluation index.After we got the weighted value,the spindle of the milling machine is firstly used to analyze the results and determine whether the results can be reproduced.Then do the destructive experiment by surface repairing or corrosion on the part or friction and wear on the part etc.Finally,the experiment suggests that the mechanical properties of the remanufactured spindle of machine tool is greatly improved compared to a new processing spindle.Therefore,from remaining life prediction analysis to remanufacturability,the article prediction presents a kind of small sample processing,parametric life assessment and life prediction of discrete mathematical models,life-cycle of the retired machine tool spindle with the methods of remanufacturing evaluation model,remanufacturability evaluation.The method not only applies to life prediction of the spindle and the remanufacturability,but also can be extended to the whole life analysis of other machine parts.This method also enriches the research content of the remaining life prediction on decommissioned machine tool components,and also provides a basis ideas for environmental protection and resource conservation.