Cylindrical roller bearings mounted to a continuous casting machine were only lasting 1-2 months before failure at a major steelmaking plant in Europe. To remedy the situation, the facility invited NSK’s team of experts to review the application and operating conditions, a process that ultimately led to the adoption of NSK’s sealed spherical roller bearings. The result: annual savings of €14,850 in downtime and maintenance costs.

The machine in question produces I-section beams using a series of rolls to maintain pressure on the profile as the molten steel solidifies. Shaft-mounted bearings support each set of rolls.

At the steel plant, the cylindrical roller bearings were lubricated with oil via a complex system of piping. Unfortunately, high maintenance costs were the norm because of the time required to disconnect and reconnect the pipes after every bearing failure. Due to the demanding nature of the application (high temperatures, contamination, high loading) – as well as the design constraints of the machine which prevented the fitting of heavier duty bearings – the service life of the cylindrical roller bearings was just 1-2 months.

To provide an improvement, NSK concluded its analysis by proposing to fit the rolls of one segment with sealed spherical roller bearings (60 in total).

NSK’s solution doubled the maintenance intervals to 2-4 months thanks to the high sealing performance of the sealed spherical roller bearings, resulting in substantial cost savings of €14,850 (for just a single segment of the continuous casting machine). Instead of the single-lip concept of standard 

sealed spherical bearings, NSK’s design takes advantage of special outward-extending, spring-loaded lip seals made from nitrile rubber, delivering robust protection against the ingress of contamination.