Elastohydrodynamic Lubrication of Stern-tube Bearings with Propeller Shaft Deflection and Misalignment

Abstract

 Observations were made of the elastohydrodynamic lubrication of stern-tube bearings on the propeller shaft with the stern-tube bearing in an inclined state. The force generated by the propeller can be neglected based on the assumption that the propeller shaft has a low rotation frequency. The magnitudes of the inclination and deflection of the propeller shaft were calculated under these conditions, and numeric values for the approximate range of inclination and deflection were measured. The magnitudes of inclination and deflection calculated under these conditions were used as parameters to calculate the elastohydrodynamic lubrication characteristics under various conditions. The relationship between oil film pressure distribution and deflection mode of the bearings was also calculated.