Abnormal noises in reciprocating compressors
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The reciprocating compressor, equipped with a flywheel, is driven by an electric motor. The bearings of the motor as well as the bearing surfaces of the compressor shaft show no temperature increase, and there is no abnormal vibration. However, unusual noises are heard at the coupling area, similar to the sound of metal hitting each other. I need help in diagnosing this issue. (The coupling is a rigid connection) Urgent!
Is the alignment of the coupling in compliance with the standards? It’s best to stop, remove the pin of the coupling, and check its alignment.
The coupling alignment is within 0.05 mm, and the bolt connections are tight. Could it be that the flywheel bolts are loose, or is there a problem with the alignment? Urgent!
If the coupling alignment data is within the specified range, stop the pump and check the tightness of the motor foot screws.
The foundation fastening meets the requirements; repeated here refers to reciprocating compressors
Does your compressor use a fixed coupling or an elastic coupling? If possible, it is recommended to stop the machine and manually turn the shaft to see whether the abnormal noise is caused by severe wear of the coupling resulting in large gaps. Also, check the crankcase to see if there are any foreign objects inside. What kind of cover does the coupling area have? Check if there’s anything wrong with the shield, and also see whether the abnormal noise occurs continuously or only occasionally
The coupling is rigid; there are no foreign objects inside. It is loose but does not make any noise, and the sound is continuous
Check whether the bolts are loose, including those of the coupling and the connecting rod crosshead
Because you said that \"there is no temperature rise in the motor bearings and compressor bearing shells, and no abnormal vibrations,\" this rules out the issue of shaft play. My guess is that the key at the compressor coupling end has loosened, or there is a crack in the keyway, which results in poor fit between the key and the keyway, causing rattling and noise. Another issue is the loosening of the bolts used for coupling alignment.
Is it loud? Is it the gland at the coupling that’s making noise?