Influence of caprolone stern-shaft bearings on propeller shaft operation

Abstract

The paper considers the conditions for reliability of the ship rudder-propeller complex, whose operation depends on the status of the stern bearings of the ship shafting. Stern bearings are plain bearings located in the vessel's stern tube, they support the propeller shaft of the ship’s shafting. The stern tube is similar for all types of ships, inside which there are located the bearings and a sealing device that prevents ingress of outboard water inside the vessel. It is pointed out that the stern bearings made of caprolone have certain advantages over other traditionally used materials. The numerical values of the main parameters of caprolone stern bearings are presented on the basis of normative and regulatory documents. It is stated that physical and mechanical properties of caprolone in almost all respects are higher than those of other materials currently used for this purpose. Along with strength and high load capacity, caprolone has a low friction coefficient (0.04-0.08). To study the contact of the propeller shaft with the stern bearing there is considered a design diagram (a beam resting on an elastic base with a stiffness coefficient k). The stiffness coefficient of the elastic foundation characterizes the elastic and mechanical properties of the stern bearing. It is proved that caprolone used in stern bearings allows increasing the reliability of the ship’s shafting by full contact with the propeller shaft, reducing vibration and noise, resisting the erosion wear, and increasing safety