The company was experiencing repeat failures of bearings fitted to the roller assemblies of its steel wire drawing machinery.
The bearing failures were leading to excessive downtime of around 75 stoppages a month, along with high maintenance costs, causing critical concern for the company’s management team.
As part of a failed bearing analysis and application review, NSK engineers identified a problem with the lubrication and sealing of the company’s incumbent bearings. In particular, a lubrication analysis showed that the existing grease was graphite-based, which was not suitable for the application. Compounding the issue was a continuous steel wire-drawing process with high loads and arduous operating conditions.
NSK recommended a new bearing and lubrication package. The solution consisted of an NSK sealed double row cylindrical roller bearing together with specially selected lithium grease.
NSK's complement cylindrical roller bearings feature high-performance contact seals that prevent the ingress of contaminants or water. Further features include inner and outer ring re-lubrication holes for ease of maintenance, and a highly corrosion-resistant phosphate coating for use in external environments (if required). Pre-lubricated with lithium grease, the sealed units offer a high load rating for increased radial and axial capability.
With the potential solution identified, the next task was to put the new bearing/grease combination through its paces via a comprehensive trial process. The result was highly positive, showing a 40% improvement in bearing life, which in turn led to large improvements in productivity and reduced maintenance costs.
The customer has since converted all of the roll assemblies on its wire-drawing machinery over to NSK’s proposed bearing/grease combination.