Influence of bearing waviness on the lubrication performances of coupled journal-thrust water-lubricated bearings

The purpose of this study is to discuss the effect of the bearing waviness on the lubrication performances of coupled journal-thrust water-lubricated bearings using an elastohydrodynamic lubrication model. The results of the numerical model are compared to the published experimental data to verify the validity of the numerical model. The load capacity and maximum fluid pressure under different parameters of waviness of coupled journal-thrust bearings are calculated by numerical model, and then the influence of the bearing waviness on the performance of coupled journal-thrust water-lubricated bearings is analyzed. The simulation results show that the waviness amplitude has great influence on the bearing performances and the effect becomes increasingly pronounced with the growth of waviness amplitude. For the waviness of journal bearings, the performances are more sensitive to the waviness arranged in bearing circumferential direction than radial direction. For the waviness of thrust bearings, the presence of circumferential waviness can improve the load capacity, while radial waviness can reduce the load capacity. With the increase of wavelength, the load capacity and maximum fluid pressure have similar periodic changes, but the change is irregular. More investigations are required regarding the influence of geometrical shape of the waviness and its wavelength on the performance of the bearing.