With increased awareness of environmental issues and regulations, developments for recent automotive engines are progressing towards engines with low fuel consumption. Due to these changes, automotive engine bearings are increasingly used in harsher environments, with higher loading and corresponding wear.
From this background, resin overlays, where solid lubricant is dispersed in a resin binder, are being developed. Resin overlays show excellent sliding properties under boundary lubrication conditions, and are known to have superior wear and fatigue resistance compared with conventional aluminium based bearings.
However, while conventional resin overlay bearings display excellent sliding properties, they tend to have inferior seizure resistance compared to Al-Sn-Si alloy bearings.
In this study, by optimizing the strength of the resin overlay layer with addition of calcium carbonate particles, a resin overlay with equal wear resistance but improved seizure resistance was developed. The performance of the developed resin overlay bearings was confirmed with rig tests and engine bench tests.