Design And Application Of Marine Plastic Bearing Tester

As the substitute for alloy bearing and lignumvitae bearing, the plastic water-lubricated bearing has been widely applied on vessels. The rapid development of plastic bearing manufactured by Thordon Bearing INC. is an example. Despite of its short history, plastic bearings developed very fast in China and some of them have been used as stern tube bearings and rudder bearings. However, how to test the performance of plastic water-lubricated bearing and whether those bearing can meet the needs of marine industry and match the rules for ship buildings or not became a series of problems.According to the requirements of GB7948-87 "Test method for PV limit of plastics bearings", a friction testing machine is designed to measure the PV limit value of marine plastic bearing. After its successful build-up, it was checked and accepted by Dalian branch of China Classification Society. A plastic bearing, produced by a domestic manufacturer, was tested on it under constant speed and variable loads. In the experiment, the PV limits of plastic bearing are measured under different bearing line speeds 0.25m/s,0.5m/s,0.75m/s, 1m/s,1.25m/s, the results of measurement turn out to be 2.93,8.15,12.23,16.3 and 20.38.In order to test the wearing capacity, the friction testing machine is transformed in accordance with DNV "Standards for certification on synthetic rudder bearing bushing materials". A wearing testing machine is designed and accepted by Dalian branch of China Classification Society. The wearing capacity is measured under the requirements of DNV "Standards for certification on synthetic rudder bearing bushing materials". The plastic bearing oscillates plus and minus 15 degrees relative to the steel jacket under the surface pressure of 10N/mm2 and the velocity of 3.5mm/s. In the experiment, the wearing capacity is measured every 48 hours. The friction force between plastic bearing and relative rotation steel jacket is recorded after a stable wearing rate is achieved, then the friction coefficient is figured out. The test shows the wearing capacity is 0.01mm after 192h continuous works.