JAJ Develops Silent Needle Roller Bearing for Electrical Components

Developed to make vehicle interiors even quieter with the electrification of automobiles
JAJ  announced that it has developed a silent needle roller bearing that cuts noise to a third that of the conventional product. The new product is perfect for electric components mounted in vehicles with extremely quiet interiors while driving under the power of an electric motor, such as electric vehicles (EV) and hybrid vehicles (HEV). It will help make the vehicle interior even quieter and contribute to enhanced comfort.
JAJ will promote this product for meeting the growing need for quieter bearings with the electrification of vehicles. It expects annual sales of 300 million yen in 2015.
Development background
The ends of rollers (rolling element) in needle roller bearings used in automotive electric components are crowned (i.e. given a curved arc) to make the bearings able to withstand a heavy load. With the conventional crowing method, the roundness of the roller ends is inferior compared to the central part of the roller, resulting in loud noise from the bearing under conditions in which the roller has a large tilt. For this reason, in EVs and HEVs, in which the vehicle interior is extremely quiet, the operating noise of electric components that traditionally would not have been noticeable can disrupt the comfortableness of passengers.
With the following excellent features, the new product contributes to improved automotive comfort by reducing noise from needle roller bearings used in electric components and drive components.
Product features
Improved roundness of crowning
NSK improved the roundness of the roller crowning by 1/4 compared to the conventional product by developing a high-precision machining method.
Product benefits
The level of noise (sound pressure) generated by bearings was cut to no more than 1/3 that of the conventional product. The product will help make quiet, comfortable vehicle interiors in EVs, HEVs, and luxury cars in which a very quiet ride is required.