WATER – AN EXTRAORDINARY, ORDINARY LUBRICATION LIQUID. INFLUENCE OF WATER SALINITY, PRESSURE AND TEMPERATURE ON WATER LUBRICATED BEARINGS PROPERTIES

Lubrication liquid characteristic has significant influence on bearing properties and working conditions. In calculations of oil lubricated bearings oil viscosity changes resulting from increasing temperature are usually taken into consideration. In water lubricated bearings the isothermal model is usually applied. In most cases, it is a correct method because of negligible viscosity changes resulting from increasing pressure and temperature in the lubrication film. In reality, water has surprisingly unique properties. One of them is strong influence of pressure and temperature on viscosity. In addition, salinity of sea water influences viscosity, as well. Since typical ships can freely sail on all oceans, the sea-water temperature could change more than twenty degrees. This wide range of temperature change has influence on properties of water lubricated bearings