Wälzlager - 2012-11-02
With its Asset Improvement Programme (AIP), NSK helps users of all kinds of machinery and equipment to find the ideal bearings for their application. Machine operators often seek NSK’s advice because they are experiencing specific problems – which is exactly what happened in the case of this particular food tin manufacturer. The producer used shielded deep-groove ball bearings in a continuous furnace and found that the bearings had an average service life of just 15 days.
Specialists from NSK assessed the bearings’ operating environment and established that the furnace had a maximum temperature of around 300°C. The bearings themselves reached a temperature of 120°C. This is much higher than the maximum temperature specified for conventional deep-groove ball bearings. The experts also discovered that the ambient air in the furnace was contaminated by particles of lacquer.
NSK then recommended the use of heat-stabilised bearings which are suitable for temperatures of up to 200°C. Thanks to NSK’s extensive materials expertise, the company has several materials in its portfolio which are compatible with high surrounding temperatures.
The seals on the new bearings are also designed to cope with the specific conditions. The furnace’s conveyor system is now fitted with deep-groove ball bearings featuring Viton seals, which means that the bearings can handle temperatures of up to 150°C. In addition to this, the seals keep ambient contamination out much more effectively than the shielded bearings previously used.
The user quickly acted on NSK’s recommendations, which proved highly effective. The bearings’ average service life was extended from 15 days to 3 months. On top of this, the whole conveyor’s operating life increased substantially – from 15 days to 6 months.
This simple replacement had impressive financial consequences. Before the AIP analysis, the cost of replacement bearings and changing the conveyor totalled €24,500. Labour costs for replacing the bearings came to almost €2,900 and production downtime set the manufacturer back €96,000. The total cost was therefore €123,400. Now, these expenses have fallen to just €8,400; purchasing the bearings themselves costs a mere €160. This is equivalent to annual savings of €115,000.