Field case · Condition monitoring
Overgreased bearing: an ultrasound lubrication check, BPFI harmonics, and a housing packed solid
Quick answer
During a live demonstration an ultrasound lubrication tool flagged a bearing as overgreased. The envelope spectrum and time waveform showed inner race defect harmonics modulated by shaft speed. Opening the housing confirmed too much grease, with smearing on the inner ring that points to skidding.
What the case covers
- The application
- What the vibration data showed
- What the teardown showed
- What to take from it
Takeaway. Inner race harmonics in the envelope spectrum do not always mean a defect. Check the grease quantity first, then repeat the measurement.
Read the full case, with the data and the numbers