• Journal of Advanced Marine Engineering and Technology
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• v.22 no.1
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• pp.85-91
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• 1998

In this paper, an influence of inlet pressure on the running characteristics of tilting pad thrust bearing is studied by a numerical analysis. The inlet pressure is obtained from the extended Bernoulli equation including the loss coefficient which is varied with the operating conditions. The running characteristic parameters such as the minimum film thickness, the film pressure and the film thickness ratios are calculated for various runner speeds with constant load in particular two pivot positions. The results are shown that the inlet pressure has a large influence on the minimum film thickness and other running characteristic parameters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.391-398
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• 2020

If the lost energy produced by a propeller can be partially recovered, the propulsive efficiency can be increased, and the fuel consumption reduced. The devices installed for this purpose are called Energy Saving Devices, of which the Contra-Rotating Propeller system is one of the most effective devices. The first problem to be solved to install the Contra-Rotating Propeller system on a large ship is that the mean pressure generated in the journal bearing needs to meet the design criteria of the classifications. In Korea, however, the practical use is being delayed because it cannot overcome this step. The next step is to lower local pressure to increase the reliability. In this study, to solve the mean pressure problem as the first step of practical use, a product carrier with a short stern shape was selected to reduce the weight of the shafting system, and a suitable shafting-system design plan was proposed. Shaft analysis confirmed that the mean pressure of 0.8 MPa (8 bar), which is a design criterion of the classifications for a journal bearing lining material (white metal), was satisfied. In addition, the necessity of reducing the local pressure was also confirmed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.527-534
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• 2023

This paper conducted a study on the application of ceramic materials for bridge bearing that can complement the durability of PTFE, a conventional bridge bearing friction material, and exhibit low coefficient of friction and friction behavior without lubricant. The ceramic material was zirconia (ZrO₂), and the friction behavior was evaluated according to the roughness coefficient. The roughness coefficient was divided into 0.8 and 0.027, and the average coefficient of friction was calculated to be 0.16 under 15 MPa surface pressure. Afterward, ceramic was made into friction material and applied to the bridge bearing, and performance comparison with PTFE bridge bearing was conducted through compression test and friction test. In the compression test, the ceramic and PTFE bridge bearing showed ideal compression behavior depending on the load. No fractures or defects were observed in the ceramic bridg bearing, but lubricant loss was observed in the PTFE bridge bearing. The average coefficient of friction of the ceramic bridge bearing analyzed through friction behavior was 0.16. The inherent material properties of the physical and chemical properties of ceramics, the excellent mechanical properties derived from the performance evaluation, and the coefficient of friction of 0.16 suggest that it can be considered as a friction material.