Bearings - 10/12/2020
Even more reliability with gearbox bearings for rail sector
Building on a long history of success in the rail industry, NSK has developed a new series of gearbox bearings that increases even further the reliability levels achieved by previous-generation products. The bearings, which can be used to support large and small gears in rolling stock gearboxes, are ideal for both high-speed and low-speed applications.
NSK’s new bearings for small gear shafts deliver a completely new level in value through even higher reliability and reduced maintenance requirements. NSK’s bearings for large gear shafts also offer superior reliability – the standard line-up has been expanded to provide a greater range of sizes to meet diverse customer needs.
Gearbox bearings are subjected to severe conditions with frequent shock and vibration emanating from the wheels clattering along the tracks. These arduous conditions necessitate regular bearing maintenance, which is often labour-intensive. Mounting and maintaining tapered roller bearings, which are commonly used to support gears and pinion shafts, requires time-consuming end-play clearance adjustment by expert maintenance engineers. This effort results in significant time and labour that increase total cost of ownership (TCO) for railway operators.
In light of these challenges, and to meet demand for even higher reliability solutions, NSK has developed new bearings that incorporate a suite of proprietary technologies. The overall effect of NSK’s innovations is to significantly enhance handling (small gear bearings only), extend maintenance intervals and contribute to lower TCO.
A low-maintenance design is among the major features of the bearings for small gear shafts. The combination of the new cylindrical roller bearings and four-point-contact ball bearings eliminates the need for end-play clearance adjustment, simplifying both mounting and maintenance. NSK ships these bearings with pre-set clearance, making it easy to achieve highly optimised results.
Another enhancement relates to cage strength, which is vital in applications where effects such as intense shock and vibration are commonplace. Here, NSK has developed a special ring-guided cage with optimised pockets employing ‘R-shaped’ corners. This novel design reduces stress in the cage structure by 75%.
The new bearings for small gears also feature an inner ring that is specially heat-treated to ensure dimensional stability, even under conditions of extended use at high temperatures. Extremely high dimensional stability delivers excellent creep suppression, preventing the bearing from shifting along the shaft.
With regard to the series of high-reliability tapered roller bearings for large gears shafts, NSK has added a number of standard new sizes in line with growing demand. Makers of rolling stock can quickly and easily integrate these widely tested standard bearings into new designs.
Major rail operators in over 20 countries trust NSK railway bearings thanks to proven quality and reliability that is built on over 100 years of expertise.
Picture 1): NSK’s new high-reliability bearings are ideal for both high-speed and low-speed rolling stock applications
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