The problem

Due to a bearing failure on the non-drive end of an elevating conveyor; which was detected by Machine Sentry®; further investigations were carried by AVT Reliability® engineers, across all conveyors within the dry receiving area of a food manufacturer who process potatoes. This investigation highlighted that there were some potentials area for failure.

The investigation found that the non-drive end bearings had pillow block bearings fitted. These bearings were not sealed correctly and required regular greasing. This type of bearing is also not water or dirt proof, yet they were located in a high contamination risk area. Figure 1, shows the elevating conveyor bearing, which was exposed to regular wash downs and contamination.

Figure 1:

Figure 2 shows the non-drive end of the common feed conveyors. The bearings here were subjected to regular pressure washing from the operators and also mud and dirt from the potatoes.  As the bearings are not visible for inspection, and it is difficult to ascertain the current condition of these bearings under normal running conditions. Which means they can only be inspected during the 21 day down day cycle, when the guarding can be removed to allow inspection. A sealed for life bearing with a protective cap would give greater confidence in the bearings condition.

Figure 2:

Once the non-drive end of the conveyor was opened, mud and dirt were visible on the bearings which was causing contamination and failure. This can be seen in figures 3 and 4.

Figure 3:

Figure 4:

Solution

After conducting the inspection, following the identification of a fault by Machine Sentry®. AVT Reliability® recommended the customer changed the bearings for a new range of food safe bearings. These bearings are sealed for life and a have a protective cover to eliminate ingress of water and contaminants to the bearing.

Additional actions have also been raised in Machine Sentry®, to ensure regular Preventative Technical Inspections are carried out. Bearings on these conveyors will also be changed in pairs, which will eliminate future unplanned downtime due to the opposite bearing failing.

Savings

From the Machine Sentry® Portal on average, 14% of assets are likely to fail in the food and beverage industry. By installing the food safe bearing and conducting regular inspections, the customer has seen a reduce cost in unplanned downtime, saving up to £10,000 per hour in lost production time.