Investigations On Composite Fretting Of The Shaft-hub Of Compressor Impeller

Compressor impeller is one of the most important parts of the turbocharger. The demandof high reliability, long life and the light weight is higher because of its high speed. Generally,compressor impeller has two assemble ways: one is the shaft-hub connection, the other is theaxial impellers-nut preloaded connection. Both assembly ways are typical fretting wear. Atpresent the study of compressor impeller fretting are very few. These fretting researches aremainly focused on single tangential fretting or radial fretting. Thus, studying the compositefretting of the shaft-hub of compressor impeller has important theory significance and practicevalue.In this paper, the finite element model of a compressor impeller in two assemble wayswere set up. The contact simulated analysis of impeller shaft-hub was processed. Theinfluences of working parameters on the fretting characteristic parameters were analyzed. Theinfluence law of the different amount of interference, friction coefficient and rotation speed onthe radial fretting characteristics on the contact surface of impeller shaft-hub was studied. Theinfluence law of preload force on the tangential fretting characteristics on the contact surfaceof wheel back-shoulder and impeller small end-nut was discussed.Based on the single fretting of the shaft-hub of compressor impeller, the compositefretting on the contact surface was analyzed, using orthogonal test. The influence significanceorder and influences of working parameters such as interference, friction coefficient androtation speed on the average of maximum unit frictional on the contact surface of impellershaft-hub and the contact surface of wheel back-shoulder were obtained through the rangeanalysis of the orthogonal test results. A group of optimized parameter was obtained. Amethod of choosing reasonable magnitude of the interference of compressor impeller shaft-hub was provided considering the fretting in this paper. This method can provide areference for the assembly design of the compressor impellers to guide the actual production,which can also be a reference to the similar design and research. These have a certainengineering application value.