Failures of the pump’s bearings are the cause of pump outages and repairs nearly as frequently as failures of the pump’s mechanical seals. Centrifugal pumps often make use of both rolling element (anti-friction) bearings and sliding element (plain) bearings in their construction. Each of these two groups of bearings can be discovered in small as…
Main, crank pin, and crosshead bearings usually wear out very slowly. Wear rates of up to 0.01 mm/10,000 hours are considered acceptable, but under normal conditions, wear rates will be lower. On the other hand, operating conditions that aren’t normal, like dirty lubricating oil, scratches on the journals, or spark erosion (for more information click…
A turning propeller is electrically insulated from the hull by the lubricating oil film in the bearings. Electrical potential is generated between the shaft and the hull and as a result the cathodic protection of the ship will not protect the propeller. Electrical potential can cause currents in the bearings resulting in pitting of the…
Crankshaft is the main element of the motor mechanism and it sums up the rotational motion of all cylinders and transmits it to the consumers, which in the case of marine engine systems can be a propeller or a generator. For this reason, from a mechanical point of view, it has the higher load and…