High-tech bearings - High-speed trains Leonardo da Vinci was a designer and scientist way beyond his time. He drew his visions of the aeroplane, the helicopter, the parachute, the sub-marine and the car. It was more than 300 years before many of his ideas were improved upon. Bearings are a good example. Although Leonardo da Vinci has been credited with the discovery of the principle behind the mechanics of ball bearings, the first patent was taken out by Philip Vaughn, a Welsh carriage-maker, in 1791. The bearing has developed much since, and keeps improving with new and challenging applications. The need to develop faster ground transport has many challenging applications. The TGV, train à grande vitesse, French for "high-speed train", is France's high-speed rail service developed by Alsthom and SNCF, the French national rail operator. Following the inaugural TGV service between Paris and Lyon in 1981, the TGV network has expanded to connect cities across France and neighboring countries. It has the world’s highest average speed for a regular passenger service, up to 320 km/h (200 mph). April 3rd in 2007, TGV set a new record for the fastest wheeled train. A specially modified train set reached 574.8 km/h (357.2 mph) speed on a test run. One of the contributing success factors to the new record were the axle bearings fitted on the train. These bearings were sourced directly from the production line of SNR, a company specialized in rail projects. In the design of bearings suited to high-speed applications, key issues are optimised internal geometry and total management of temperature issues. Yohan Souteyrand, Manager of the Rail Industry unit explains: "The striking thing is that, for the record-breaking run, at twice the speed of normal operations, the bearing temperature rose no more than 10°C". SNR first started working in the high-tech rail market at the start of the TGV high-speed train programme. New types of bearings were designed, specially tailored for highspeed applications. SNR axle, transmission and engine bearings have been fitted on French TGV trains ever since and the company had been part of the previous recordbreaking team in 1990 (515.3 km/h, or 320.2 mph). Partnering with the biggest European rail projects, these special bearings are fitted on the Eurostar, the Dutch PBKA, the Korean bullet train, France's double-decker TGVs and the new Eastern TGV line. Through its specialised Rail Service unit the advantages of high-performance bearing design and production expertise will benefit other rail markets, such as Intercity trains, locomotives, freight wagons, metros and trams. Speed Link InfoService Request more information by e-mail Reader Service No. Reader Number Email Address 01126    Tell a friend about this article:
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