Material Study for Advanced Stern Tube Seals and Bearings for High Performance Merchant Ships.

摘要

The objective of the program was to conduct a comprehensive material study for stern tube bearing and seal applications primarily for oil-lubricated usage. Selected polymeric materials were subjected to soak tests and friction and wear tests. The liner materials were subjected to corrosion tests. Based on the tests,the following materials were recommended for bearing and face seals:polyimide, 15% graphite power filled;polyamide-imide, 3% Teflon and 12% graphite powder filled;and phenolic, 15% graphite powder filled. The liner materials could be the same as those which are currently used:ABS Grade 2and NOROC for bearings,and Niresist Type 2for face seals. The materials could also be successfully used in seawater lubrication. Materials recommended for lip seals are:Butadiene Acrylonitrile Copolymer -NBR. Vinylidene fluoride-hexafluoro propylene copolymer Viton 2282,and Perfluoroelastomer (Kalrez 1050). NOROC 277seems to work better and this or its equivalent should be used. It is recommended that the elastomers should be filled with solid lubricants to improve their friction and wear properties without loosing hardness and other desirable mechanical properties.