A Study on the Application of New Lining Material for Ship Propulsion Shafting System

Exothermic accident at the rear part of the after stern tube journal bearing is mainly caused by an excessive local compressive pressure at the rear part as the propeller weight deflects the propulsion shaft. By using a material with lower stiffness than white metal, which is used for the lining of stern tube bearings, it would be possible to decrease the local compressive pressure by increasing the contact area with the shaft, eliminating the cause of exothermic accident. We analyzed the shafting system in order to investigate the compressive pressure distribution characteristics and allowable pressure when a new, less rigid material is applied. The analysis results confirmed that a low-stiffness product can significantly decrease the local compressive pressure compared to an existing product when applied to an actual ship. Furthermore, the pressure distribution changes were small even when the loading condition was changed, allowing for a robust design. (paper)