Automotive - 2010-02-12
NSK has developed ultra low-friction sealed clean ball bearings with half the friction of conventional sealed ball bearings. The company will market this product for application in manual transmission (MT) vehicles, which are generating high demand in emerging markets and Europe, and double clutch transmissions (DCT), a popular style of transmission in Europe that combines fuel efficiency with a sporty feel. NSK targets sales of this product of at least 1.5 billion yen by 2015.
NSK fitted bearings with seals are used inside transmissions to inhibit the ingress of gear dust and other contaminants. These sealed clean ball bearings, which provided drastically longer service life and superior reliability, have been adopted by major auto makers around the world since their release.
In recent years, rising environmental awareness has created demand for automobile transmissions that do more to improve fuel economy, which has in turn created expectations for reduced friction in transmission bearings. NSK’s newly developed ultra low-friction sealed clean ball bearings cut friction to half the conventional level, thanks to the product features detailed below.
NSK has based the new lineup on ball bearings already being produced at its many ball bearing manufacturing sites around the world, so as to meet worldwide demand in a timely manner by shipping from the nearest facility.
1. Lower torque
Straining force was reduced by 50% by narrowing the seal lip by 10% and lengthening it by 70% compared to usual bearings, based on computer simulations of the lip shape. This enabled the creation of ball bearings with the lowest friction in the world - half the conventional level.
2. Same durability as conventional products
The seal lip shape was improved base on computer analysis; the new shape improves lip-following and stabilizes contact pressure along the edge. While reducing straining force, this made it possible to realize the same durability as conventional products by preventing the ingress of contaminants to the transmission oil in the bearing.
NSK has achieved compact, lightweight and low torque applications for automobiles by leveraging its four core technologies (tribology, materials, analysis, and mechatronics). The company has been developing these technologies for over 90 years, and is continuing to create products that will improve the fuel efficiency of automobiles. Next, NSK will take on the challenge of even further reducing overall friction in transmissions.