Study on Damage of Propeller Shaft Sleeve for Seawater Lubricated Rubber Bearing-1st Report

Propeller shaft diameter of ferries becomes larger in conjunction with requirements of higher vessel's speed and CPPs (controllable pitch propellers) . Thus, it may lead into a tendency to reduce the life duration of stem tube bearing under seawater lubrication. Wear of the propeller shaft sleeve, i.e. bronze alloy, is typically greater than that of the rubber bearings, with triangularly shaped craters appearing on the sleeve surface.In this paper, we describe the investigation of used sleeve sample taken from an actual vessel, as well as the wear characteristics of bronze alloys conducted under the corrosive wear condition which is equivalent to actual ferry service. The results indicated that corrosive wear was the main cause of sleeve wear. Comparing between the amount of wear in seawater and the one in distilled water, the influence of corrosion on sleeve wear was found to be substantial. Additionally, the craters are considered to be formed by the action of erosion corrosion