Engine Bearings - From Design to Maintenance 390182
SIX major causes of bearing failures are catalogued, which include matters of engineering and design, procurement practices, misuse and abuse in operation, faulty installations, unsuitable lubricants, and mechanical faults in the bearings themselves.
Although there are four general types of bearing materials in common use today for main and rod bearings - tin-base babbitts, high-lead babbitts, cadmium alloys, and copper-lead mixtures, the author shows that not one of them is a universal bearing material - each has its own particular field of usefulness, and these fields are defined in terms of maximum unit pressure, Zn/P, PV, oil-reservoir temperature, and crankshaft hardness.
Design factors that react against indicated satisfactory performance are considered, including strength and stiffness of the bearing structure, oil flow to the rod bearing, restrictions in feed grooves, oil clearance, and so on. Standards of design pertaining to these points are set up.
The need for, and the advantages to be gained by, more comprehensive bearing purchase specifications are emphasized.
Identification of failure, due to misuse and abuse, is treated largely by illustration of typical examples.