Polymeric Engine Bearings for Modern Engine Applications Solution for aggressive bearing operating environments

摘要

The operating environment of an automotive half bearing is radically changing as a result of modern engines driven to improve fuel consumption and reduce CO_2. Engines are adopting various technologies and strategies such as start stop/hybrid systems, downsizing and low viscosity oils. Engine bearings should operate under hydrodynamic lubrication, but, more often the bearings have to operate under mixed or boundary lubrication for increased durations without compromising the bearing system durability. To attend to this difficult aggressive operating environment MAHLE have developed a proprietary polymer overlay. The foundation of the coating is a high strength, temperature and chemically resistant polymer matrix. An addition of solid lubricant, metallic fillers, adhesive promoters and specific curing regime generates the desired properties. Rig and engine test results demonstrate excellent wear and fatigue resistance performance compared to conventional uncoated bearing materials. The overlay is suitable to be applied to aluminium and copper based substrates which enables it to be utilised for a wide range of applications.