Press Release

NSK's High-Performance Bearings Employed in Hokuriku Shinkansen (Bullet Trains)

Wide-Ranging Contribution to Rolling Stock

NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) today announced that its high-performance railway axle bearings have been selected for the E7 and W7 Shinkansen trains of the Hokuriku Shinkansen Line, which began operations in March 2015.

Railway bearings are important safety-critical components. They have a direct influence on the safe operation of railways and must comply with the highest safety requirements. In addition, they face the critical challenges to being compact and light in order to save energy and reduce impact on the environment. Shinkansen trains in Japan carry many passengers safely over long distances. The bearings selected for the Shinkansen trains must be highly efficient and durable and must pass strict quality controls.

A truck; a railway bogie.

Image provided courtesy of East Japan Railway Company

Bearings Selected and Product Features

(1) Oil bath, double-row cylindrical roller bearings for the axle bearings.
This product generates little heat in the bearing, enabling high-speed rotation. It also ensures a long service life for the bearing, an important factor for trains that travel long distances.
(2) Ceramic-coated insulated bearings with proven safety and lightness for the traction motors.
This product helps to enhance reliability and prevents the occurrence of electrolytic corrosion, a factor which reduces bearing service life. This type of corrosion is caused by sparking in the bearings of electric motors where electric current flows.
(3) High-strength retainers, with soft nitriding treatment for outstanding shock resistance for gear units.
This product contributes to enhancing the reliability of traction motor bearings, which are subject to significant vibration.

NSK Bearings for Rolling Stock

Bearings for rolling stock are required to be safe and highly reliable. They must also be compact, lightweight, and able to perform at high speeds. In addition, they must be easy to maintain. In 1916, NSK developed the first ball bearings in Japan, and in 1932, NSK developed a tapered roller bearing for Japanese National Railways (JNR) gasoline rolling stock. In this and many other ways, NSK supported advances in Japanese-made rolling stock, contributing to improved safety, high-speed performance, reliability and energy savings that today have placed the Shinkansen and other Japanese-made rolling stock in a world-leading position. Furthermore, in 2012, NSK developed Japan's first passenger train car axle sensor bearing and made other such technical advances. NSK has the highest market share of railway bearings in Japan and has been expanding its this business overseas to China and Europe.

NSK will continue to develop its business globally for railway bearings and will continue to help make trains even more environmentally friendly.