The effect of misalignment on performance characteristics of engine main crankshaft bearings

The effect of static misalignment on the dynamic behaviour of a main crankshaft bearing is examined in this paper. The mobility method of Booker is used to predict the performance parameters of the bearing such as the minimum oil-film thickness and the journal centre cyclic path under dynamic load conditions. The theoretical results are compared with those of an aligned bearing. The Ruston–Hornsby 6 Veb-X Mk III engine big-end bearing is selected as an example to validate the computer program incorporating the present analysis. It is shown that the misalignment has significant effects on the minimum film thickness and the journal centre trajectories even for the low values of misalignment parameters. It is also found that the presence of circumferential feed grooves can cause metal-to-metal contact in such bearings.