NSK supplies railway vehicles with a wide variety of bearings for wheel axles, drive units, and traction motors. NSK bearings offer high performance, high reliability, and long periods of maintenance-free service to support rail companies in providing quick, safe, and dependable transport.
Our bearings have a long history in Japan's Shinkansen bullet trains, from the first 0 series right up to the latest sets. We supply Shinkansen trains with bearings that use oil-bath lubrication and sealed bearings with grease. Since axle bearings are instrumental to train safety, we developed and equipped bearings with condition-monitoring sensors for practical use.
In addition, our proprietary high-reliability tapered roller bearings have a long track record. Because drive units face harsh vibrations, these bearings undergo a soft nitriding treatment to increase cage strength. They also feature specifications that improve seizure resistance on the rib face.
NSK is also highly sensitive to changing industry needs. Trains are getting faster and faster—To maintain reliability at high speeds, we developed cylindrical roller bearings with ribs specially designed for drive units that use double helical gears.
For longer periods without maintenance, we developed specialized cages with excellent grease replenishing capabilities. Damage caused by electric erosion is another big maintenance issue, yet here too we deliver solutions in the form of ceramic and resin insulated bearings.
As proof of our commitment to quality in all our products, we continue to be certified by the Association of American Railroads (AAR) and in 2018 obtained ISO/TS22163 (prev. IRIS) certification for business management system requirements for rail organizations.
NSK strives to thoroughly grasp the actual conditions and environments where bearings are used and faithfully recreate these in evaluation testing. We work tirelessly to establish advanced measurement technologies and improve on simulation technologies.
We meticulously measured the motion of the rollers in cylindrical roller bearings used in actual Shinkansen trains and the distribution of load on the rolling elements when the axlebox is deformed. With these advanced measurements and feedback from results, we have created sophisticated analysis and design technologies and work toward ever more accurate simulation technology to reproduce real-world conditions.
NSK's technical developments in railways are not limited only to bearings–With safety and value as top priorities, we continue to challenge ourselves in the pursuit of new bearing condition monitoring systems. By also developing and bringing vibration control actuators to market, we contribute to a smoother ride by reducing the sway of rolling stock during operation.
Tapered Roller Bearings
Tapered roller bearings can support high radial loads and axial loads in a single direction. When used in pairs (two or four rows), they can take axial loads in either direction.
Cylindrical Roller Bearings
With line contact between rolling elements and raceways, cylindrical roller bearings have high radial load capacity and are suited for high-speed applications.