Molded Oil bearings save quarry EUR14,389 per year

NSK's Asset Improvement Programme (AIP) for cost reduction has achieved a major success with a large quarrying and mining company, delivering achieving annual cost savings of EUR14,389 per year as a result of solving an ongoing bearing reliability problem on an overhead quarrying conveyor; the existing bearing inserts were replaced with with NSK's innovative Molded Oil bearings.

The problem with the conveyor was regular failure of bearing inserts every two months or approximately 440 hours of operating time. These failures were due to the harsh environment where the inserts were exposed to ingress from water and abrasive particles. Furthermore, the bearings were assembled 5m above the ground, which made inspection and maintenance tasks difficult.

While the annual cost for replacing the bearings themselves was not too onerous, at EUR540, this figure was dwarfed by the annual cost for the downtime resulting from the bearing failures: EUR15,750. What all this added up to for the quarry was an annual cost of EUR16,290 for bearing failures and the resulting downtime and lost production.

AIP cost reduction programme

Clearly this cost was unsustainable, so an initiative was launched with a view to sourcing higher-performance bearings. As part of this initiative, engineers from NSK's AIP cost reduction programme were called in to give advice. The cost reduction programme is a value-added service that helps bearing users to improve reliability, reduce operating costs, and improve efficiency and profitability. These objectives are achieved by delivering tangible savings to assets, such as equipment and machinery, and also by improving the working knowledge of maintenance and engineering personnel.

NSK engineers visited the quarry, inspected the overhead conveyor and identified the problem. They suggested using NSK's Molded Oil Bearings, which they were certain would last longer.

Molded Oil bearings employ a special solid lubricant to transform the performance of machinery in environments exposed to high humidity, corrosion and contamination. The bearings achieve improvements in performance and reliability by offering more than twice the operating life of grease lubrication in water-contaminated environments. The solid lubricant technology also means that there is no need to replenish the lubricant, as Molded Oil provides a continuous supply of lubricating oil.

Molded-Oil bearing inserts were fitted to the conveyor and have subsequently provided an dramatically extended bearing life. The bearings have already exceeded the life of the previous bearing inserts by a factor of nine, delivering 19 months of trouble-free operation (around 4140 hours). The resultant savings from this improved operation are considerable. With less than one replacement a year, maintenance cost is just EUR63 and downtime cost EUR1838, giving a total cost per year of EUR1901 - which equates to an annual saving of EUR14,389.

Contact NSK for more information about Molded Oil bearings.