Misalignment analysis of journal bearing influenced by asymmetric deflection, based on a simple stepped shaft model

The effects of journal misalignment on a journal bearing caused by an asymmetric rotor structure are presented in this study. A new model considering the asymmetric deflection is applied. Also, the thermo-hydrodynamic of the oil film in the journal bearing and straightforward elasticity theory are considered in the analysis. Based on the structure stiffness equivalent characteristic, a simple stepped shaft can reflect the entire complex structure model. The existing lubrication model, which does not consider this angle component, is not very precise for journal bearings. Film pressure, misalignment angle, velocity field, oil leakage, and temperature field were calculated and compared in the journal bearing analysis. The results indicate that bearing performances are greatly affected by misalignment caused by the asymmetric structure. A simple stepped shaft can effectively represent a misaligned journal bearing in a rotor-bearing system.