Here are some common Lubrication issues that CBM Partners have found during recent Site Lubrication Benchmark Studies. These highlight the importance of Precision Lubrication and provide a few tips by way of simple case studies.
Is the Grease Reaching the Rolling Elements?
Excess grease can bypass the outer ring of the bearing if the bearing and housing are from different manufacturers or if the bearing is incorrectly inserted. Always verify the compatibility and correct installation of bearings.
Problem: Grease bypassing the outer ring.
After removing the excess grease, it was found that the bearing didn’t follow the outer ring groove due to mismatched components. This issue can also happen when the inner swivel bearing is inserted incorrectly.
Solution: The bearing was removed, the insert checked, fitted correctly and a test purge of grease carried out prior to refitting
Future Preventive Actions:
- Test purge bearings before installation.
- Ensure compatibility of bearing and housing components (only change complete units, not parts).
- Clean and check bearings before lubrication to confirm correct grease distribution/purge position.
Importance of Correct Greasing Frequency
Over-greasing can be as detrimental as under-greasing as the following finding shows:
Problem: In this case, the bearing covers (which are used as protection from the rotating shaft) were hiding an over greasing problem. These bearings only rotate every 45 minutes for just 1 minute and only during 5 days of each week.
Solution: Using the lubrication calculator, “type of rolling elements, bore and OD of the bearing”, the frequency of lubrication was increased, but lubricant applied was reduced by 80%.
Sticking with the Same Habits
Problem: These bearings were being greased at the same frequency and volume as always … but the production running time had changed! This led to incorrect greasing of the bearings (fig 1 shows old grease and signs of lack of grease to the bearing).
Solution: All the bearings were cleaned of the excess grease (see Fig 2). The bearings were greased to identify purge (Fig 3) and then cleaned prior to start up (Fig 4 – any excess will purge on start up). The bearings were checked 13 weeks later, confirming that only 33% of the original grease amount was and is necessary. Lubrication was reduced from 3 grams to 1 gram per application, and a critical plant route was introduced.
External Lubrication Services: Busting the Myth
It’s a common misconception that hiring external lubrication services will increase lubricant usage. In most cases,especially when the lubrication services company is independent from a lubricant manufacturer, grease lubrication is reduced as improved lubricants are utilised and frequencies of use correctly calculated to avoid over greasing. Gearbox oil usage does generally increase though as, in most cases, oil changes haven’t take place….until it’s too late and failure has occurred! In the case of gearboxes, more regular oil changes and better maintenance lead to longer term savings.
Professional lubrication services can optimise your reliability program and make your machinery more efficient, saving you money both directly and indirectly by improving asset longevity.
With Thanks to
Robin Thomas
Lubrication Services Director
