The Fault Analysis And Reliability Growth Technique Study For Electro-spindle

Electro-spindle is the key functional component of CNC lathe, its reliability levelhas the directly influence on reliability of CNC lathe. Therefore, reliability study ofelectro-spindle is an important link in reliability study of CNC lathe. The paper carrieson systematic analysis of electro-spindle to find out weak link that influence onelectro-spindle reliability, proposes targeted effective improvement, provides gist forreliability design for new product of electro-spindle to avoid or reduce such incipientfault on new product with the purpose of improving reliability of electro-spindle.Firstof all, the paper divides subsystem of electro-spindle based on structure and workingprinciple of electro-spindle of certain machine center, to determine failure mode andfailure cause of electro-spindle subsystem by using electro-spindle of certain serialmachine center. The statistical analysis for field failure data of electro-spindle is tofind out weak link of electro-spindle, and carry out criticality analysis forelectro-spindle subsystem on the basis of statistical analysis to find out and improvethe high criticality subsystem of electro-spindle.Secondly, the paper carries outincipient fault analyses of electro-spindle by using Petri net and establishes faulttransitive Petri spindle net mode of electro-spindle to give the dependence relation ofelectro-spindle fault visually.The association matrix of electro-spindle fault is got byPIPE, the minimum cutset of electro-spindle fault is obtained by Matlab whichprovide a theoretical basis for electro-spindle fault restoration in an effective anefficient manner. The PIPE is used to emulate and simulate the transitive progress ofelectro-spindle fault and the method of graph theory is used to solve fault diagnosisreasoning problem. Thirdly, according to fault analysis of electro-spindle, broachinstitution is the key subsystem of electro-spindle. The paper combine dataenvelopment analys(DEA) method with risk priority number (RPN) method establishinstitution fault risk model.With the help of MATLAB, the paper rank for broachinstitution fault risk to find out the emergency failure mode of broach institution thatneeds to be improved.In conclusion, on the basis of fault analysis of electro-spindle subsystem, thepaper takes design, manufacture, assembly and outsourcing into comprehensiveconsideration to propose reliability growth improvement of electro-spindle; supervisedevelopment work for new product of electro-spindle and improve inherent reliabilityof electro-spindle. The slake test for initial failure of electro-spindle is designed toslake initial failure of electro-spindle and improve use reliability of electro-spindle.