Rolling bearings are key components in all areas of beverage production: blowing, filling-capping, labelling, conveying and palletising. Their performance, reliability and operating life have a significant effect in ensuring that operating costs are minimised and production efficiencies increased. In addition, as bearing technology accelerates, opportunities for technology transfer mean that bearings can play a wider role in reducing the life costs of machines. This is achieved by applying new materials, sealing and lubrication technology to improve the machine design and reduce its maintenance costs.
NSK has used its development experience to design and manufacture a range of bearings, the Spacea series, which help beverage equipment OEMs and equipment users to achieve all the above objectives, thereby solving problems, improving performance and enabling continuous improvement into the future.
The Spacea series of bearings provides high performance and reliability under demanding operating conditions: corrosive, super-clean, high/low-temperature, high-speed vacuum and non-magnetic. The bearings meet a wide range of technical requirements with a programme of high-performance materials, surface finishes and specially developed lubricants, including solid types.
To enable customers to meet the demands of a broad range of applications in water, alkali and strong acid environments, NSK has developed the Aqua-Bearing, a special highly corrosion-resistant bearing for light-load applications in the operating temperature range up to 40degC. The use of a special fluorine plastic for the inner and outer rings and a fluorine plastic cage enable the Aqua-Bearing to achieve corrosion resistance equal to ceramic bearings and better than that of previous generations of plastic rolling bearings made of PE (polyethylene) or PPS (polyphenylene sulfide). The effectiveness of NSK's materials specification means that the Aqua-Bearing is also able to handle applications in strong acids or alkalis, ozonised water, various kinds of vapour and halogen gases.
In addition to providing improved corrosion resistance, the fibre-reinforced fluorine material gives the inner and outer bearing rings increased strength and rigidity. It is also said to provide an endurance life of over 1000 times that of A1S144OC stainless steel bearings and five times that of previous PE bearings under light loads in acid solutions.
For operations in corrosive environments where higher temperatures are encountered (up to 200degC), NSK has developed Spacea bearings with nickel-coated inner and outer rings of Martensitic stainless steel, ceramic balls and fluororesin cages. These bearings are grease-free, employing a high-performance fluorine solid lubricant. They offer higher corrosion resistance than stainless steel bearings and are claimed to have longer operating life than hybrid bearings and stainless steel bearings in acid solutions: four times as long for hybrid types, and twelve times that of stainless steel units, when tested in an NaCl solution.
Where the problem is more lubricant- than material-based, NSK offers its stainless steel range of Moulded Oil bearings. These units employ a special solid lubricant to transform the performance of machinery and equipment in terms of reliability, maintenance intervals and operation, in environments exposed to high humidity, corrosion and contamination. The effectiveness of Moulded Oil technology enables machine builders to make real cost savings by replacing existing, and often costly, methods of lubricating machine parts. In 'real world' tests, Moulded Oil is claimed to offer more than twice the operating life of grease lubrication in water-contaminated environments. In addition, the technology means that operating environments are kept free of grease and there is no need for refilling of lubricant, as Moulded Oil provides a continuous supply of lubricating oil.
The benefits of Moulded Oil technology also extend to beverage applications where manufacturers want to employ the prefabricated advantages of ball bearing units. The bearing units - pillow block, flange and take-up types - are manufactured from stainless steel. They are suitable for applications where cleanliness and a high resistance to corrosion are required. In addition to Moulded Oil lubrication, customers for the bearings have the option of a special USDA H1-compliant food grade grease.
Offering a lower cost option in applications where frequent washdowns are required is NSK's Silver-Lube range of ball bearing units. These are a range of corrosion-resistant mounted bearing units designed specially for use in industries where hygiene considerations and corrosion and chemical resistance are important; typically bottling and brewing, food processing, pharmaceuticals, fisheries and chemical processing.
Silver-Lube housings - pillow block, two- and four-bolt flange types - are manufactured from PBT. This is a high-quality glass-filled thermoplastic polyester resin, which has excellent strength, stiffness, dimensional stability and chemical resistance. Integrated into the housings are bearing inserts with stainless steel raceways, cage, balls and grub screws. The inserts are charged with a food industry-approved grease, and are easily re-greaseable via a stainless steel grease nipple in the housing. They are protected against contamination by a stainless steel flinger and seal arrangement.
More comprehensive details of NSK's bearings for beverage applications are contained in a new 24-page publication. The free booklet provides information regarding the choice of bearings for use in beverage applications. Free copies of the publication are available from NSK's Marketing Department on +44 (0)1636 605123.