engleski

Methodology for testing shaft slide bearings of the ship propulsion system

From a technical and economic standpoint, the suitability of a ship's propulsion system depends significantly on the bearings of its shaft line. The paper compares oil-lubricated white metal stern tube slide bearings and water-lubricated polymer stern tube slide bearings. Practice has taught us that with water-lubricated polymer bearings, the minimum thickness of the lubricant film is significantly smaller compared to white metal bearings that are lubricated with oil. With insufficient lubricant film thickness in the bearings, liquid friction can easily change to mixed friction due to a certain disturbance. The disorder can result in an increase in load, temperature, a decrease in viscosity and speed, and a change in the geometry of the bearing sleeve. In particular, it is known that in the case of a realistically loaded water-lubricated stern tube slide bearing, the influence of the elastic line curvature of the sleeve is greater than the minimum thickness of the lubricant film. Due to the eccentric action, the thrust force of the ship also has an influence on the elastic line of the sleeve, comparable to the influence of radial loads. In the case of water-lubricated bearings, the influence of the change in the intensity of the thrust force and the size of the eccentricity also changes the curvature of the elastic line of the sleeve to the extent that there is no fluid friction along the entire length of the bearing. The wear of the polymer bush has an impact on the ecosystem. The paper points out the need to apply analytical and numerical models of the sleeve in the bearing and the need for testing that will faithfully simulate the condition of the stern tube slide bearing on the ship at sea.

stern tube slide bearing ; water lubrication ; curvature of the elastic line ; testing of slide bearings

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