Achim Adam

Crankshaft bearings for engines with start-stop systems

The challenges placed on engine bearings are growing along with the improving efficiency of modern combustion engines. Depending on the driving situation, fuel-efficient start-stop systems for instance increase the number of cycles that take the crankshaft and the bearing half shells through a phase of mixed film lubrication. A new overlay from Federal-Mogul based on reinforced polyamide-imide prevents wear which metallic sliding surfaces tend to show during such punishing use.

Kurbelwellenlager für Motoren mit Start-Stopp-System

Mit steigender Effizienz moderner Verbrennungsmotoren wachsen auch die Anforderungen an die Motorlager. Start-Stopp-Systeme beispielsweise erhohen je nach Fahrsituation die Zahl der Zyklen, bei denen Kurbelwelle und Lagerschalen eine Phase der Mischreibung durchlaufen. Eine neue Gleitschicht von Federal-Mogul auf Basis von mikroarmiertem Polyamidimid verhindert den Verschleis, den metallische Laufflachen unter solchen Bedingungen typischerweise zeigen.

Development of Engine Bearing Solutions for New High Output Automotive Engines

With the development of advanced engine technologies, which includes direct injected, turbo-charged, variable valve timed, flex-fuel, hybrid start-stop cycles and a general downsizing of engine architectures, bearing surface areas have decreased and connecting rod loading has increased. As a result, modern bearings experience decreased oil film thickness, more frequent non-hydrodynamic lubrication periods and higher surface sliding speeds. Subsequently, bearing applications demand an increase in fatigue and scuffing resistance. In response to this, two new complementary material developments are documented: one a new aluminum based lining material, the other a polymeric surface layer. The new lining material, called A-650, was developed to have improved fatigue strength relative to existing Al engine bearing lining options. Results for rig testing of fatigue and seizure resistance properties are provided, along with engine test evaluations using multiple fuels. The polymeric surface layer, a polyamideimide based resin called IROX™, is intended as a durable surface coating providing exceptional wear and seizure resistance under high sliding speed and start-stop conditions. Furthermore, an increase of the specific load capacity is achieved with aluminum based substrates. A description of the material, with test results, is included.Copyright