Sliding Surface Profiling of Plain Journal Bearings

Several cases of rod bearing shells assembled in highly loaded engines have been reported to show premature wear of the sliding surface, more specifically the electroplated lead-tin overlay.

To understand these phenomena and overcome such occurrences, an analytical method has been developed to simulate the operation of specially designed journal bearings featuring circumferential profiling of the sliding surface. The resulting computer program solves the Reynolds equation taking into account a non-circular bearing surface, thus allowing for a customized design which extends operational component life through minimum oil film thickness (MOFT) increase and peak oil film pressure (POFP) and bearing back temperature (BBT) reduction. Theoretical results show an effective way to prevent premature wear.

The geometric aspects drawn from those investigations were introduced in the manufacturing of bearing shells provided with relieves, which, after being tested in automotive engines, proved to enhance their operation, granting more reliability to the engines.