NSK’s cost reduction programme has achieved a major success with a customer in the food processing industry, achieving annual cost savings of €189.166 per year on a potato processing line, as a result of replacing sealed, single row radial ball bearings with its ‘Molded Oil’ bearing technology.
The bearing problem was traced to the rollers of a potato peeling machine, where the harsh nature of the process meant that the sealed radial ball bearings in the rollers were suffering ingress of water and dirt, causing premature failure.
The failures represented downtime costs of €164,364 a year and additional maintenance costs (€20,550) associated with bearings replacement and frequent lubrication. The total annual loss attributed to the problem amounted to €189.352.
As part of the food manufacturer’s strategy to ameliorate these unsustainable losses, a team of engineers from NSK’s cost reduction programme was invited to the plant to investigate and advise. NSK’s cost reduction programme is a value-added service that aims to help 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.
The Molded Oil bearings that were subsequently specified employ a special solid lubricant to improve the performance and reliability of machinery operating in environments exposed to high humidity, corrosive substances and contamination. The lubricant is contained within the bearing, avoiding contamination and the need for regular re-lubrication.
Sample Molded Oil bearing inserts were fitted to the rollers of the peeling machine and these operated successfully for more than ten months without problems. Having already provided over four-times the life of the previous single row radial units, the bearings were subsequently removed for inspection, which revealed their continuing serviceability. On the strength of this, the food producer replaced all the single row radial ball bearings on the potato peeler with Molded Oil units.
Winds of change
By employing a programme of material substitution and longer life lubrication technology, NSK also helped a manufacturer of micro wind turbines to achieve cost savings of €337,600. This manufacturer is also benefiting from extended product life, improved reliability and reduced maintenance, as a direct result of replacing high-cost, mixed brand bearing products with NSK’s premium brand bearings and long-life grease.
A review of the machine design by an NSK engineer highlighted several areas where unit build cost could be substantially reduced. Following this review, a supporting design justification report plus bearing and grease life calculations were produced. These not only underpinned the design cost reductions, but also promised benefits such as simplified assembly and improvements in overall bearing performance, reliability, and life expectancy.
The customer acted upon NSK’s recommendations, substituting NSK premium brand single row radial ball bearings, where before there had been a selection of mixed brand products, including single row radial ball bearings and angular contact bearings. The NSK units are long-life grease lubricated, which is good for more than 200,000 hours as opposed to the 22,400 hours for the mixed-brand bearing package. This improvement alone has enabled major reductions in maintenance to be achieved, helping to keep the micro turbine in service substantially longer. Quantifiable improvements for the turbine manufacturer are in excess of €337,000.
NSK is producing similar cost saving results across other, disparate industry sectors. The company’s cost saving programme looks at all aspects of bearing system implementation, including design, lubrication and even staff training issues.
The process often starts with a site survey, during which any operational problems are analysed in great detail. Data acquired from the visit are carefully studied and suggestions given as to how improvements might be made. These improvements are then quantified in cost terms, demonstrating the level of savings that can be expected by adopting a revised bearings plan.