Stuttgart-based Mahle has developed a new polymer coating to extend the service life of bearings by reducing friction and increasing seizure resistance, while simultaneously improving the boundary lubrication properties.

Bearings found on the connecting rods, crankshafts and camshafts of combustion engines are put under increasingly high loads due to the emission control measures that are now in place.

The new polymer coating with melamine cyanurate has unique lubrication properties, thanks to its low friction coefficient on account of its multi-layered structure.

This enables a quicker transition of the bearing to a hydrodynamic lubrication region. At the same time, melamine cyanurate has a high thermal stability, enabling it to ensure a more robust operation of the bearing under
conditions of inadequate lubrication.

This allows a 20% increase in the load limit at which the bearing shell starts to seize.

The new bearings can therefore easily withstand the elevated loads that increasingly arise in the course of an engine’s life, due to emission control measures such as the use of stop-start systems and hybrid or coasting operation.

The significantly higher performance parameters have been demonstrated in exhaustive bench and engine tests.

Andreas Pfeifer, head of product development engine systems and components at Mahle, said: “The new polymer coating is a good example of how the continuous optimisation of the combustion engine can contribute to reducing emissions.

“As part of its dual corporate strategy, Mahle is constantly driving forward the optimisation of the combustion engine, which it sees as an important element in the environmental and economic viability of the drive mix of the future.

“At the same time, Mahle is accelerating e-mobility and working on solutions to make electric vehicles affordable and suitable for everyday use.”