Will it all come out in the jetwash?

food hygiene regulations require frequent wash-downs with high-pressure hoses, water and contaminants inevitably find their way inside the unit

The greatest enemy of the bearing unit is the jetwash. When food hygiene regulations require frequent wash-downs with high-pressure hoses, water and contaminants inevitably find their way inside the unit, at the same time as the lubricating grease is forced out: with the resulting corrosion leading to accelerated replacement. Which is why the RHP Silver-Lube^® bearing unit from NSK looks set to clean up.

The RHP Silver-Lube range of corrosion-resistant bearing units has been specifically designed for industries with aggressive cleaning regimes, such as the food sector. Not only does the bearing use a thermoplastic housing, all the components such as the grease nipple, bolt-hole liners, set screws, bearing rings, finger seals, cage and balls are made from stainless steel. In addition, the units can be supplied with molded oil, to prevent water intrusion and eliminate the problem of the lubricant being forced out by water pressure during a wash-down.

The PBT thermoplastic resin used for the Silver-Lube housings is, of course, non-corrodible in water, as well as being resistant to detergents and many chemicals – which means even aggressive cleaning will not affect it. With a smooth finish for more effective wash-downs – and paint- and coating-free – the housings won’t chip or flake, so there is no risk of contaminants entering the process.

Of course the corrosion resistance of the housing is only part – though an important part – of the story. The bearings themselves need to be fully-functioning to the standards required, as well as being easy to install, long-lived, requiring minimum maintenance and providing a low cost of ownership.

Bearing units in the Silver-Lube range are available in pillow block, two- and four-bolt flange, and take-up unit configurations, and use a spherical seating arrangement to retain the bearing insert in the housings allowing relatively high misalignment tolerance. This makes installation or replacement quicker and easier as there’s no need for time-consuming laser alignment. Once fitted, they can be relubricated for a longer, trouble-free life: minimising maintenance and maximising productivity.

The Silver-Lube range is the culmination of years of research, development and testing, resulting in a highly efficient design. Engineered by NSK to the strictest tolerances, the range is manufactured from fully-traceable raw materials, including high-grade, precision ground stainless steel. The units are charged with an FDA-approved food grade grease as standard, and they are also available with moulded oil if required.

Even compared with cheaper, lower quality imports, a Silver-Lube unit is competitively priced, and is readily available from ERIKS. So in the short-term it’s a cost-effective solution, and in the long-term – as the case study shows – it can actually save you money.

Fresh fish processor makes savings on an impressive scale

The hygiene requirements for a fresh fish processing line demanded at least two wash-downs of a conveyor every day. The water and contaminant ingress which resulted was badly damaging the conveyor bearings, to the extent that failures were taking place as often as every six months. In one six month period alone as many as 60 bearings had to be replaced.

With two fitters taking three hours to replace the bearings, the company was spending £18,600 a year on bearing replacement, plus inevitable associated downtime and lost production costs.

A number of Silver-Lube bearings were installed on the conveyor on a trial basis. At the end of six months, none of the units had failed and all were still performing ‘as new’. As a result, the remaining bearings on the conveyor were also replaced with Silver-Lube units, and after 12 months there were still no failures.

The fish processor has estimated the resulting total savings on bearing replacement at £11,700 a year.