Press Release

NSK Develops Japan's First Passenger Train Car Axle Sensor Bearing

Improved Safety and Reduced Maintenance for Rolling Stock

Rolling Stock Axle Sensor Bearing

Tokyo, Japan, May 21, 2012 - NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) announced that it has developed Japan's first passenger train car axle sensor bearing. It offers improved safety and reliability as well as reduced maintenance. In Japan, this product is already ensuring safe operations for trains by West Japan Railway Company (JR West) in the 321 series (rapid train) and the 521 series.

Series 321:Photo provided by West Japan Railway Company

Railway bearings are safety-critical components that have a direct influence on the safe operation of railways. They must be highly reliable. In addition to consistent reliability, they are also required to be light and compact to conserve energy and reduce the impact of railways on the environment. Bearings used in rapid trains, which carry passengers to many train stations at rapid speed, need to ensure good ride comfort and need to have high durability and good maintenance. NSK has been constantly further improving the reliability and functionality of railway bearings for many years. This new product, which is Japan's first passenger train car sensor bearing, makes it possible to constantly monitor the rotation speed of the axle bearing for improved safety and reliability.

This product is expected to be used in a wide variety of applications: not only does it improve safety, it also reduces maintenance workload. Additionally, this sensor houses multiple sensing functions (temperature, vibration, rotation speed), making it expandable as a high functionality multi-sensor.

Product features:

1. High-precision sensing function
The sensor is directly mounted to the seal of the axle bearing, making it possible to detect the rotation speed of the axle. This helps to prevent wheel slips during braking. In this way, damage from wheel flats that occur due to wear from slips can be prevented, also preventing deterioration in ride comfort and impact to rail track equipment. This in turn provides for improved safety and reduced maintenance.
2. Compact and easy to install
This product can be installed in small spaces, making it possible to install into existing train cars by simply replacing the axle box, bearing and peripheral parts.
3. Sensor reliability
These sensors are used outdoors and therefore exposed to conditions of sunlight, wind, rain and snow. As such, they must have strong weather-resistance performance to withstand hot and cold conditions and must be waterproof. In addition, each time that a train car passes over a joint in the train tracks, these sensors are exposed to strong impact. This product is capable of withstanding shock levels in excess of 100 G and has sufficient durability to withstand the repetitive vibration that occurs while the railway bearing is in motion.

NSK bearings have supported the progress of the Japanese railway industry from the beginning. Continuous improvements in the areas of safety, high speed, high reliability and energy conservation have placed Japanese railways including the Shinkansen bullet train in a world-leading position. NSK’s railway bearings support the further advancement of compactness, light-weight and high speed and can be easily maintained. Today, NSK railway bearings take the top market share in the Japanese market.

NSK will continue to expand its business of supplying bearings for rolling stock that contribute to making trains more environmentally friendly.

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