NSK, Motion & Control

Automotive News

NSK Develops Lightweight Lipped Thrust Race for Automatic Transmission

NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) announced today that it has developed a more compact, lightweight, longer-lasting lipped thrust race for use in automatic transmissions.

Low viscosity transmission oil is commonly used today to improve transmission efficiency, but this creates lubrication challenges. NSK’s new product is designed for outstanding performance in severe lubrication conditions, and also helps to improve fuel economy. NSK expects sales of this product to reach one billion yen by 2015.

Development background

In recent years, automakers looking to improve fuel economy, reduce gear shift shock, and raise power transmission efficiency have increasingly turned to the multi-stage automatic transmission. Low viscosity transmission oil is often employed in these transmissions to reduce agitation resistance, which has a negative impact on transmission efficiency. This type of oil presents lubrication challenges for the thrust needle bearings typically used in transmissions. Meanwhile, demand is increasing for more compact, lightweight transmission bearings that can help improve fuel economy in hybrid electric vehicles (HEVs). When HEVs run on the electric motor alone, the oil pump sometimes stops, which in turn requires the thrust needle bearings in the transmission to function on lean lubrication. NSK’s new lipped thrust race will help improve fuel economy and reduce CO2 emissions by meeting the need for more compact and lightweight bearings that are more than ready for challenging automotive applications. Product features are summarized below.

Product features
 
Thickness greater than 2.5 mm, made possible by using a steel material with improved press workability

The new product is made of NSK’s proprietary PCR5 steel material, which features improved toughness achieved by reducing the amount of carbon and silicone and increasing the amount of chrome. This enabled the new product to be press worked despite having a thickness greater than 2.5 mm.

Carbonitriding

NSK’s propriety PCR5 steel—employed in the lipped thrust race—has been carbonitrided for enhanced toughness, surface hardness, and fatigue strength.

Effects

1. Service life at least three times longer than a conventional thrust race
2. 20% more compact and lightweight than a conventional thrust race
3. Usable under challenging, low viscosity oil lubrication conditions, such as in HEVs

About NSK

Established in 1916 and headquartered in Tokyo, Japan, NSK is a world class manufacturer of motion and control products, leading the industry with superior quality, engineering research and technical innovation. NSK produces and distributes a wide range of rolling element bearings, linear motion and automotive component products for a variety of applications.

Operating in the Americas, NSK Corporation is a member of the NSK Ltd. group and is headquartered in Ann Arbor, Michigan. NSK Corporation has a network of sales and engineering teams working in partnership with customers to deliver high performance products, application-specific solutions, superior technical support and exceptional service to the Americas market. The company’s strategically located manufacturing and distribution centers supply both original equipment manufacturers and the industrial aftermarket through a broad distribution network.

For more information, visit www.nskamericas.com.