NSK's Asset Improvement Programme (AIP) has achieved 10-times bearing life and made significant savings on downtime and maintenance costs for a major company in the quarrying and mining industry that was experiencing frequent reliability problems with casting units assembled into a vibrating drum.
The reliability problems were resulting in bearing failures every two months, or 440 hours of operation. They were caused by the severe environment in which the casting unit support bearings operated. The environment was wet and mechanically demanding. Worse still, the bearings were often exposed to large amounts of sand, which often covered them completely resulting in harsh abrasive ingress, and subsequent premature failure.
In addition to the problem of regular bearing failures, there was another issue, in that the bearings were difficult to access, making replacement difficult.
In view of the difficulty of the operating environment, the NSK engineers proposed using Self-Lube Triple Lip Seals on the vibrating drum bearings. These seals provide maximum protection in applications having the highest degrees of contamination.
The Triple Lip seal consists of a one-piece moulded nitrile seal with three sealing lips, bonded to a protective steel outer pressing, which is robustly secured in the outer ring of the bearing. This arrangement delivers a highly efficient sealing arrangement for use in the worst types of operating environment.
Fig. 1. Quarrying & Mining industry that was experiencing frequent reliability problems with casting units assembled into a vibrating drum.
Fig. 2. NSK Self Lube Insert.