Lubrication Problem at a Coupling
Low vibration levels masked a coupling issue in a motor, detected through spectrum analysis and time waveform inspection. Dry lubrication was found and addressed, preventing potential failure.
Hidden Coupling Issue Detected Despite Low Vibration Levels
On regular inspection, one motor showed low vibration (max 3.5 mm/sec), but the spectrum showed 1X harmonics and time signal had periodic impacts at MDE and Fan DE – clear signs of a possible coupling issue or rotating looseness(This was not suspended due to acceleration values are low)
Based on these indicators, we suspected a coupling-related issue and recommended inspection during the next PM
Upon opening the resilient coupling, we found the lubrication was completely dry.
We cleaned out the old grease and applied fresh grease.
✅ After maintenance, the motor is running smoothly with stable vibration levels.
🔍 This early detection helped us avoid a possible failure.
Key takeaway: Even if overall vibration is low, always check the spectrum and time waveform!
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