Influence of Surface Finishing on Bearing Performance

This work presents an experimental study to analyze the influence of surface finishing on engine journal bearing performance. Bimetallic bearings were manufactured with two bored finishings, one called conventional and another microprofiled. Microprofiled bearings have a potential advantage due to the higher conformability of these parts under the engine operational conditions.

Bench tests and engine test were conducted in order to check the loading carrying capacity (LCC) until seizure occurrence; the temperature was evaluated at the steel back of the tested parts. Surface of the parts was evaluated after the tests.

The results showed that microprofiled bearings presented slightly lower temperature at steel back during the bench tests than the conventional bearings. The loading carrying capacity for both parts was similar, due to the relatively low speed test. The temperature at the steel back of the bearings with microprofile was a slightly lower than in parts with conventional finishing, probably due to the better heat dissipation on the microprofiled finishing. Parts with conventional finishing presented polished areas after the engine test; parts with microprofiled finishing presented a homogeneous aspect, but these parts presented higher wear. However, microprofiled parts can better accommodate the loads and system misalignments, increasing its LCC and fatigue resistance.