JAPANESE firm NSK has developed heat resistant steel for improved durability in its innovation of a high-performance cartridge bearing for automotive turbochargers.
The cartridge bearing offers improved reliability and low friction loss for turbocharger use. NSK plans to expand the sales of this product for improved fuel economy throughout Europe and other regions where turbocharger use is quickly expanding.
By employing proprietary heat-resistant steel that is optimal for high-temperature and high-speed conditions, NSK has dramatically improved seizure toughness. This NSK-developed steel provides for long life, even in debris-contaminated engine oil conditions.
Using proprietary analysis technology for dynamic friction, NSK was able to optimise the internal specifications of its bearing. In doing so, it has succeeded in developing a bearing that is both reliable and has a low level of friction loss. Furthermore, the integrated cartridge bearing has a high level of assembly accuracy and is low in vibration and noise.
For the bearing cage, NSK employed a heat-resistant plastic material that can be injection moulded for low friction loss and improved cost competiveness.
Using this high-performance cartridge bearing will improve the response of turbochargers. This makes it possible to further expand the use of turbochargers, thereby it will improve the fuel economy of automobiles, NSK says.
In recent years there has been an urgent need to reduce emissions and improve the fuel economy of automobiles. Due to this trend, many automobile manufacturers are downsizing engine displacement for improved fuel economy. In connection with this trend, the demand for turbocharger use is expanding in order to offset the loss in engine power resulting from engine downsizing.
Turbochargers need to be durable enough to withstand high-temperature and high-speed rotating conditions. Up until now, sliding bearings have been used for such applications. However, sliding bearings tend to have a high amount of friction loss, and this is driving the demand for rolling bearings that are highly reliable in high-temperature and high-speed rotating conditions.
