CM of Bearings

Bearing Condition Monitoring is a crucial & most important function in maintenance. The major part of maintenance is spent on bearings. Today the popular CM tool for bearings is Vibration Analysis but it’s a misconception in reality.

In reality, Vibration Analysis is not a suitable CM tool for bearings. Rather, Vibration Analysis not even a Condition Monitoring tool. (But Vibration Measurement is) You can refer to our blog, Condition Monitoring Concept & Misconception to know more about it.

Along with a longer & tedious analysis process, Vibration Analysis or even Vibration Measurement doesn’t actually detects any lubrication faults (Over Lubrication, Contamination, etc). We know that the reason behind most of the bearing failures i.e. around 80% of the bearing failures is lubrication mistakes like lubricant contamination, over lubrication, under lubrication, mixed lubricant, improper lubrication, etc. and Vibration at bearing doesn’t reveal lubrication faults but bearing faults – faults at outer/inner race or at raceway or at the cage, Whereas Ultrasound Measurement detects any type of lubrication faults in bearings.

To monitor the bearings periodically and get a Trend of Readings, it is necessary to use Combination of CM Tools. When any fault arise in bearing its temperature, noise & spike energy starts increasing. It requires to monitor only two factors temperature & noise with the tools thermography & Ultrasound measurements, & draw a trend. Rather Ultrasound Inspection is the best method/ tool to monitor condition of bearing. Even a lubrication problem at prior stage can be detected with trend of ultrasound readings.

We conduct CM of bearing with Ultrasound Inspection mostly and sometimes we use a combination of techniques like Ultrasound Measurement & Thermography. For bearings, which are very costly & at a critical position, we use a combination of all three techniques, Vibration Spike Energy Analysis, Ultrasound Measurement & Thermography.

We monitor bearings with combination of tools, Thermography & Ultrasound Measurements. The CM report contains two trend analysis charts, one of temperature and other is Ultrasound.

If the trend shows an upward trend (fault condition) then the root cause can be investigated (RCA) with Ultrasound Analysis – for lubrication faults &/ or Vibration Analysis for other faults.