Vibration analysis is a well proven method for identifying machine faults while still in the early stages, enabling planned maintenance to be implemented. Adopting this condition based maintenance has obvious advantages over date fixed, excessive maintenance or even worse, reactive maintenance and repairs. TPI offers a range of equipment to help reduce maintenance costs and increase reliability, as the following demonstration details.

The problem

Across the client’s sites, the number one cause of system failure was found to be bearing faults. In over 90% of cases, failure was identified as being due to the lubrication condition/deterioration. The client’s challenge, in between visits from a vibration consultant, was to find a low cost, easy to use, method to measure and ensure that the new grease is getting to the bearing. And where a risk is found, a method to monitor the risk of failure needed to be implemented.

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Failing to ensure this was resulting in unscheduled, extremely costly, bearing replacements and secondary damage. A bearing change onsite was £3000; if it was not possible to replace the bearing on site, the cost could be upwards of £15,000 (consider also the downtime and risk to the plant if the asset needs to be sent away). Therefore, knowing the bearing condition and changing on demand in a controlled situation would save a lot of money and reduce the risk of system failure to the business.

Demonstration

During a survey by a vibration consultant using a high-end vibration kit it was established that a motor needed lubrication and a centrifuge main rotor drive end bearing had a high-risk defect. However, the goal was to prove whether a lower cost, easy to use vibration meter would identify if the motor needed lubricating and that the centrifuge bearing was damaged.

The TPI 9071 was chosen as a low cost vibration analysis meter, coming in at under £500, to quantify if there is good lubrication at the bearing, as, even at this low cost, it also will alarm velocity levels to ISO and measure the acceleration impacting levels of the bearing.

Task 1: Can the TPI 9071 detect a low lubrication level on a bearing?

Readings show that this motor needs lubrication as the BDU (bearing damage unit) was 72 (amber warning). The ‘g’ level is less than 1 so it’s not badly damaged.

The maintenance team lubricated the motor, and this was the reading 48 BDU and in the green, afterwards. In addition, the ‘g’ level reduced, now there is no metal to metal from the rolling elements.

Task 2: Can the TPI 9071 detect the high-risk damaged bearing on the rotor?

This is the reading from the NDE/back end main rotor bearing, with a BDU level of 29 indicating a good lubrication condition and the ‘g’ level is less than 1 so the bearing has no major damage.

In contrast the drive end main rotor bearing has a BDU level in the RED at 260 and the ‘g’ level is over 1 at 2.63 – indicating a damaged bearing. This was lubricated and the levels did not reduce proving the bearing is damaged, this need replacing rather than lubricating.

Conclusion

The TPI 9071 is proved to give the desired results and allow the maintenance team to gauge the health of the asset easily and quickly:

1) By using a simplified traffic light indication format

2) They now know greasing the bearings are prolonging the useful life of the bearing

3) Or they need replacing, which can then be scheduled at a more convenient time, rather than wait till a much more costly firefighting breakdown occurs.

Solution

Purchase TPI 9071s for the maintenance team as the cost payback for the unit will be instantaneous.

The cost for the TPI 9071 is £495 each.

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