This article will answer the following questions:
How do I identify the cause of a machine failure?
Why do bearings fail?
How do I prevent loss of production / increase asset utilisation?
This was an interesting sample I came across recently, I thought I would make into a case study. The bearing on a conveyor line in a food production factory failed suddenly causing a whole production process to go down. The bearing was sent to the manufacturer and the grease was sent to our lab to analyse. The sample had considerable metallic content and a palpable gritty feel from all the metal in the sample.
For the client the maintenance practices were very good in that lubricant area was re-greased at recommended intervals, the bearing was not overloaded, all daily checks were in place and at the recommended OEM intervals the bearing was inspected for signs of wear visually.
However the bearing still failed much earlier than expected hence even replacing components before end of expected life does not help with random failures. In this food production process the effects of the failure were:
- Severe downtime costs from lack of ability to produce product with missed supermarket deliveries.
- Staff ready to pack final goods sat around because nothing to pack meaning high wage costs and overtime when ready to catch-up.
- Food wastage, as food had begun to spoil before a replacement bearing was fitted.
- Overtime of maintenance engineers to get the production line up and running again.
- Increase in courier costs for express deliveries to make sure already late deliveries get to client as soon as possible.
- Disappointed clients as missed deliveries – if not handled right this could lead to damaged brand image in terms of being reliable.
- Cost of replacement bearing.
These costs can be in the hundreds of thousands depending on the business, and although at this point the full costs have not been calculated it is expected to be >£100k as the total impact of this failure.
I inspected the grease sample and determined the bearing had failed from severe fatigue (see pictures below with some particles over 200 microns in size.)
The manufacturer of the bearing analysis confirmed these findings in their own analysis. The question for the client was how to stop this in future, which is where a complete condition monitoring package would benefit them. In this particular instance regular grease laboratory analysis likely could have identified and prevented this failure had the client had such a programme in place.
Naturally after this failure the client was interested in more details of our lubricant analysis programmes.
Lube analysis can help you keep your machinery running and avoid the costly implications of a catastrophic failure. It is a pity it takes a catastrophic failure for clients to even consider a lube oil programme. So rather than wait until your production line fails to start sampling, why not be proactive and find out more about starting your sampling programme today.
You are welcome to choose your own preferred lab and it doesn’t have to be my own lab you use as the important thing is you sample with a reputable lab with good engineering and chemistry experience rather than the specific one you use. If however you would be interested in using my lab please contact us on +44 (0) 113 201 2065 to find out more.