Services - 20/10/2024
NSK Keeps Trains on Track
Historically, the traction motor bearings used in the subway system of a world-famous city were overhauled every four and a half years. When the company responsible for the maintenance of the system sought to extend that period by 12 months, NSK stepped in to ensure that the trains continued to run not just on time, but safely, reliably and economically.
A traction motor is responsible for the propulsion of a train, and the bearings within it have to stand up to the sheer weight of the vehicle and be able to operate for long hours, maintenance free. As such they need to be powerful, reliable and safe.
However, with other components on the train only needing an overhaul every five and half years, the maintenance team naturally wanted to see if the bearings could stand another twelve months of operation. This would mean the team could carry out more maintenance in one go, reducing downtime significantly. It goes without saying that any improvements had to be made without a drop in reliability.
NSK has a great deal of experience in this sector, and our products are integral to some of the busiest and most prestigious rail services in the world, including the famous Shinkansen bullet trains in Japan.
We brought all this experience to bear when we determined the lifespan of the parts in question, performing an on-site examination of bearings that had been in service for multiple years and conducting detailed testing at our European Technology Centre to determine their remaining life.
Specifically, a metallurgical examination was performed which included a Bearing Condition Analysis, a microstructure check, wear analysis, hardness testing and a grease study which looked for contamination and water content. The results were conclusive, we declared that the bearing life could be safely extended to allow major overhaul intervals to be increased to the five and half years requested.
Olivier Billard, NSK Europe’s Sector Manager for Railways, says that the work carried out at this underground system is emblematic of NSK’s approach to the rail sector. ‘Everyone here at NSK understands the important role our products play in this industry. Rail operators require reliable and safe components, and we have a duty to supply those. But we also regularly go above and beyond to provide the best possible service.
‘Across the sector, railway operators want their bearing providers to extend the interval for routine maintenance and grease replenishment. The work we have done on this occasion shows we have the experience, the engineering skills, the quality of product and the robust sealing technologies to extend these intervals across Europe.’
As a further example of NSK’s commitment to our partners, our engineers also took the opportunity to assess the greasing methods that were in place and suggested small, easy-to-implement changes, that would nevertheless help prolong bearing life.
In conclusion, our engineering support allowed the bearing overhaul period to be increased by twelve months, meaning the trains that are the lifeblood of this renowned capital could operate for longer without maintenance breaks and reducing downtime generally. This change was implemented across 140 trains and resulted in a significant cost saving without any detrimental impact on reliability or safety.
To find out more about NSK's products and services for the rail sector, click here.
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