NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) today announced that it has developed a low-torque tappet roller for the rocker arm* of automobile diesel engines.
This new product uses chrome plating on the shaft of the tappet roller to improve the durability for needle roller versions. As a result, it is now possible to replace double roller versions that have a sliding bearing with a needle roller version that has a roller bearing featuring low friction loss. NSK is targeting global sales of 1.5 billion yen in 2019 for this new product, which will help improve the fuel efficiency of automobiles.
* Rocker arm: A mechanism that utilizes the force of the cam to open and close engine valves.
In recent years, there has been an increase in environmental awareness, which has led to the need for improved fuel efficiency in automobiles. This need has in turn driven the demand for diesel engines, as they have high thermal efficiency and low CO2 emissions.
However, diesel engines generate soot-NOx (nitrogen oxide) and SOx (sulfur oxide)-during combustion, making for a very harsh environment that increases the likelihood of corrosion wear in the shafts of tappet rollers. As such, tappet rollers used in rocker arms up until now have been designed with a high level of durability.
This time, NSK has developed a new needle roller version (roller bearing) that achieves low friction and high durability. As such, it can be used to replace the conventional double roller version (sliding bearing) used for diesel engines.
This product contributes to improved fuel efficiency in automobile diesel engines.
