Traditionally vibration analysis has been a complex condition-based maintenance technique requiring high cost equipment and extensive user training. At the specialist, ‘higher’ end that may still be the case, but TPI products such as the 9080 Smart Vibration Trend Meter are now offering a solution to anyone to use vibration analysis. 

From a single button press the 9080 Vibration trend meter processes extremely complex mathematical algorithms and then presents the user with concise, colour-coded alarms relating to machine condition. This includes:

•  Low frequency fault indicators, ( including mounting stability and other low frequency faults). 

•  High frequency fault indicators, (including bearing and gearbox problems).

•  Unbalance of rotating machines, particularly fans and blowers.

•  Misalignment, for example in couplings between motors and their driven unit.

•  Looseness.

In addition to powerful analysis, another key feature which the 9080 has in common with more costly analysers, is the ability to dock with PC-based software. The software is used to create inspection routes and generate trend data on your assets. Monthly monitoring of machines, and the resulting trend plot make it very easy to detect machine deterioration. Once wear starts it increases exponentially – nothing ever becomes less worn!

Case study

Simpler vibration analysis leads to more widespread use. As an example, we cite a company that is involved in the installation and maintenance of pumps and motors that routinely uses vibration analysis to measure and report on machine condition, which leads to informed maintenance. One recent fault discovery is an excellent example of how major problems can be avoided.

During routine inspection a maintenance engineer was using a 9080 Vibration Trend Meter to generate a Word format report to show that all assets were currently working properly. Instead he revealed a serious problem which could have led to unexpected failure and downtime. The front screen of the meter immediately went red suggesting a low frequency fault. The vibration spectra recorded by the 9080 Smart Vibration Trend Meter is pictured ??above??

As expected, a peak can clearly be seen at the run speed of 24Hz (1440 RPM), as indicated by the run speed cursor, but there is also a higher amplitude peak below the run speed. What causes high vibration at a frequency below the run speed? Typically this is indicative of a bearing cage fault.

Given that a cage fault was suspected the unit was pulled straightaway. Unlike natural fatigue seen through bearing race wear, cage faults are unpredictable. The cage is at risk of collapsing at any time leading to catastrophic failure. The pump unit had recently been installed and it could be argued the check formed part of a commission. It is most likely caused by damage on installation. Using the 9080 Vibration Trend Meter detected  the fault and more serious failure was avoided, removing the risk of further consequential damage as well as the loss of the pump.