High axial vibration on a Motor fan due to a Timing Belt Tooth broken
Shabir AHMAD
FLNG Offshore Condition Monitoring Technician at Coral Sul FLNG - Eni Rovuma Basin B.V. – Offshore Mozambique
Equipment: A belt driven Utility Cooler fan
Motor RPM : 1473
Fan RPM : 311
No of blades: 07
Mounting : Vertical
Symptoms and test results: The fan's axial vibration was 3 mm/sec Peak in history.
weeks later the axial vibration amplitude sudden increase to 10.89 mm/sec Peak .
Non synchronous energy was observed in spectrum
Amplitude on 1.38x & 3.34x.
Severity level as per ISO Standard :- High
Vibration values have sufficient severity to cause damage to the machine.
Diagnosis & Recommendation
1- Need to check belt looseness .
2- Pulley alignment.
Plan
Due to the sensitivity of the fan the fan PM is planned next day.However, when the fan was inspected the belt tooth was found broken, and the motor radial clearances was also increased.Belt has been replaced & motor also replaced with new one .
Condition Monitoring at PDO(Oil & Gas)Category II ISO18436-2 Certified Vibration Analyst
6 年Increase In Vibration levels might due to bearing clearance disturbed and alignment disturbed respectively ( 1.38X and 3.34x of fan speed or motor speed??)
Helping worldclass industries to be more safer, reliable, efficient and ecofriendly
6 年Was there any trip configured? Increase in vib was step increase or gradual increase?