Restoring Scrapped Turbine Bearing Supports of GM Turbochargers Through Optimized Press-Fit Interference Bushing

摘要

A computational procedure is proposed for optimized restoration of turbine bearing supports used in GM turbochargers. Although the geometry configuration of the turbine bearing support exerted serious limitations, the bushing method was successfully implemented through FEA and optimization. To study the mechanical behavior of the inner bush in different interference grades, a computational approach is introduced. Press-fit interference is traded with temperature difference between the bush and the main part via thermal expansion coefficient, and through design of experiments and response surface analysis stresses are verified for a range of various press-fit interferences. An optimized press fitting was implemented so that not only was a secure friction contact provided between the bush and the main part but also critical stresses remained below allowable limits. Successful rebuilding of 27 turbine bearing supports resulted in a savings of 33750$ during 2012.