For the past four years a hot rolling mill at a steel plant in Spain had been experiencing unexpectedly short bearing life, leading to costly production stoppages. As a result, the plant worked closely with the Technical Department at leading bearing specialist NSK to assess the application and propose and implement a solution based on high-performance spherical roller bearings. By adopting the recommendations set forward by NSK, the steel plant is now saving €69,803 per annum in reduced costs for downtime, maintenance, bearings and lubrication.
When performing a technical root cause failure analysis, NSK’s expert team closely analysed the working conditions, as well as the lubrication regime to optimise running conditions and prolong life. Furthermore, in support of the maintenance department’s request for process improvement, NSK undertook a review of the bearing fitting process and tolerances.
Working in partnership with the steel plant, the information from the analyses and reviews indicated that the high running temperature of the bearing was emanating from a combination of incorrect fitting and lubrication failure due to higher productivity (running speed) at the plant.
Among the many recommendations was the implementation of NSKHPS (High Performance Standard) spherical roller bearings with higher radial internal clearance to better suit the application conditions. Spherical roller bearings from NSK can withstand arduous operating conditions. These bearings resist seizure and wear in spite of constant vibration, misalignment and shock loads.
As a result of the new measures, bearing consumption at the steel plant has reduced to one fifth of the previous level, with subsequent benefits in less production downtime and maintenance.
NSKHPS spherical roller bearings not only offer temperature stability up to 200°C, but a dynamic load rating some 25% higher than the industry standard. The upshot is a bearing that provides twice the operating life of conventional alternatives.
Aside from advanced motion technology, NSK can offer customers extensive guidance on maximising the performance of bearings. In the case of the hot rolling mill application, the result of this advice was greater bearing life. However, the company can add value in many other ways, including the generation of higher productivity, the reduction of stock/inventory, enhanced customer skills through targeted training, delivering on-site inspection and/or installation services, the provision of technical reports or lubrication analyses.
The steel plant was very pleased with NSK’s recommendations and their subsequent benefits, as evidenced by a new order for NSKHPS spherical roller bearings when the market started to recover from the effects of the Covid-19 pandemic at the beginning of 2021.