(From: CMB-CETA Editor)

Schaeffler is to be awarded the Steel Innovation Award 2009 for its lightweight balancer shaft with rolling bearing supports for modern, four-cylinder car engines. "The lightweight balancer shaft with rolling bearing supports improves running characteristics and reduces fuel consumption", according to an explanatory statement from the jury of this prize which is awarded every three years.

The rolling bearing supports with reduced friction characteristics enable a significant improvement in energy efficiency compared to the plain bearings which were previously used. In this specific case, the power consumed internally in the engine is reduced in total by 1.5 kW (2.0 PS). The rolling bearing supports also enable a new optimized mass layout of the balancer shafts with a mass that is reduced by around one third. This means the two balancer shafts alone, which run at twice crankshaft speed due to the design, reduce engine weight by more than a kilogram. The filigree design minimizes the shaft’s rotational inertia and, thus, in turn reduces the driving forces required. The innovative design of the balancer shaft, which was developed by INA Schaeffler in cooperation with forging specialist Hirschvogel, also considerably reduces the requirement for oil cooling and makes the previously obligatory pressure lubrication no longer necessary.

The lightweight balancer shafts with rolling bearing supports are currently used in the modern, four-cylinder diesel engines from Mercedes-Benz.

"Along with the significant advantage of energy efficiency, the lightweight balancer shafts with rolling bearing supports also benefit comfort," says Dr. Peter Solfrank, Head of Application Engineering responsible for rolling bearings in passenger car engines at Schaeffler. In addition to the known application in diesel engines, this technology is also suitable for use in petrol engines. The lightweight balancer shaft with rolling bearing supports, thus, plays a key role in successful downsizing in engine construction.

A new element is also the fact that the lightweight balancer shaft offered by Schaeffler is used at the same time as the inner raceway of the rolling bearing. As a result, the inner rings of the main bearings are no longer required because the rolling elements run directly on the hardened shaft. This is a forged shaft as opposed to conventional balancer shafts which are cast.

Schaeffler, thus, offers vehicle manufacturers a complete solution which has been proven in high-volume production. Drivers also gain – from increased comfort – and a reduction in fuel consumption and CO2 emissions of around one percent.