Lubricating oil system Lubricating oil serves two functions in a steam turbine: l. It provides an oil film to reduce friction between moving parts. 2. It removes heat generated in the bearings conducted along the or shaft. A common lubrication system is used to oil the turbine, supply gearbox and thrust bearings and the gear sprayers. The turbine, rotating at high speed, requires a considerable time to stop. If the main motor driven lubricating oil fail supply of pumps were to an emergency