At the InnoTrans 2022 international exhibition for transport technology (20-23 September, Berlin), NSK will showcase a full suite of bearing solutions for axleboxes, traction motors and gearbox applications. The company is accelerating its active engagement with European rail OEMs, particularly in the high-speed passenger segment, and will use InnoTrans to highlight its product innovation, performance and quality at Booth 260 in Hall 20.
Among several products in the spotlight will be NSK’s axlebox bearing solutions. The company has already enjoyed good success on high-speed passenger rail transport systems both in France and the UK, demonstrating reliability, long service life and safety with its RCT sealed-clean tapered roller bearings.
NSK’s RCT bearings are highly integrated with surrounding components and incorporate advanced sealing solutions to ensure durability and optimal performance. Notably, these innovative bearings demonstrate the ability to accommodate complex load conditions, including high shock loads, static and dynamic radial loads, plus axial loads.
Elsewhere on the 40m² booth, NSK will present its solutions for traction motors. The key to reliable AC traction motor bearing operation is in the insulation. If high-voltage current is conducted through the bearing it can cause electrolytic corrosion on the bearing raceway and rolling element contacting surfaces that will result in premature bearing failure.
NSK offers a number of alternative designs for insulated bearings to overcome this phenomena, including cylindrical roller bearings and deep groove ball bearings featuring outer rings that are plasma-sprayed with an optimised alumina-based, ceramic coating. This insulating barrier layer, which exhibits high mechanical strength and can handle high loads, increases reliability by preventing any opportunity for electrolytic corrosion. NSK’s ceramic-coating process is proven daily on Japan’s Shinkansen (or Bullet) latest generation high-speed, passenger trains.
The most recent innovation for traction motors is NSK’s hybrid deep groove ball bearings, which incorporate ceramic balls as the rolling elements for applications where first-class electrical insulation is necessary and/or high speeds are required. Withstanding the same load capacity as standard steel bearings, NSK’s hybrid deep groove ball bearings reduce friction levels and generate less centrifugal force which both contribute to extending service life. Maintenance cost can be reduced due to increased grease life.
A further solution available from NSK in this area is PPS-insulated bearings. Glass-fibre reinforced, polyphenylene sulphide (PPS) resin serves as an insulating coating on the external diameter and side-face surfaces of the bearing outer ring to guard against electrolytic corrosion. While the physical properties of PPS are slightly reduced when compared to ceramic, the resin material is more economical, it is ideal for new generations of conventional passenger trains equipped with AC traction motors.
NSK will also present its gearbox bearing solutions at InnoTrans. In fact, the company will display a mock-up model of a locomotive gearbox featuring a selection of innovative bearings. NSK’s solutions for this application, which are suitable for a wide range of gearbox designs, feature high seizure resistance, high shock and vibration resistance, low heat generation, plus a low-wear design that increases fatigue life. NSK has been supplying tapered roller bearings for helical gears in Japan’s high-speed passenger trains for many years.
As well as bearings, the NSK booth will provide InnoTrans visitors with the opportunity to observe a highly responsive and efficient NSK ball screw actuator as a solution for active vibration control on railway vehicles. A further area of the booth will be dedicated to B&K Vibro, who are now part of the NSK group, which will display its state-of-the-art VCM-3 condition monitoring system and AS-064 acceleration sensor which enables data collection, vital for planning robust maintenance strategies.
The latest-generation passenger trains are operating at ever increasing speeds, which places increasing demands on bearing technologies. NSK continues to work with its rail industry partners, in both the OEM and aftermarket sectors, to create products that can improve safety, performance, comfort, weight reduction and cost-efficiency. InnoTrans visitors are invited to engage with NSK’s knowledgeable team of experts at the show, who will be pleased to discuss specific projects or applications.