Ph.D. Tezi Görüntüleme

       In this study fatigue properties of plastic journal bearings including PTFE-bronze layer was experimentally investigated by using an experimental apparatus in which dynamic load is applicable in different forms, magnitudes and frequencies. The pressure distributions occurred at the surface of the journal bearing was determined. Further, stresses and deformations occurred at the journal bearing was calculated numerically by using ANSYS Finite Element Code.

       Stress distributions at the surface of the journal bearing were determined by using Finite Element Method. The variation of the stress distributions at the interface of PTFE-bronze layer and the steel backing which is important in fatigue point of view were investigated. The equivalent stress distributions based on von Mises yield criterion were calculated and the critical points to initiate fatigue cracks in bearings were determined.

       At the end of this study, the maximum oil pressure and fatigue cracks were observed in the most heavily loaded regions of the bearing surface. It was also found that the most critical region for stress distribution was found to be at the interface between PTFE-bronze and steel backing layers. Moreover, it was obtained that the axial stresses were effective as much as tangential stresses in fatigue failure of the journal bearings. It was calculated that PTFE-bronze layered journal bearings showed superior fatigue behavior than the bearings including white-metal alloy under the conditions tested in this study.

      Keywords: Dynamic Loaded Journal Bearing, Plastic Bearings, Pressure Distribution for Hydrodynamic