Seeking advice on the reasons for the fragmentation of the main shaft bearing in reciprocating compressors
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Our company has four 6M units. After they have been in operation for a while, the main shaft bearings are removed for inspection. The condition of the main shaft bearings in all four units is as shown in the figure below. The bearing clearance is always within the specified range during each installation, and the oil pressure remains stable. Apart from quality issues, what other factors could cause this situation?
If similar problems occur in multiple bearings, could there be an issue with the measurement of the end play? It may be caused by significant vibration; in addition, measurements of the clearances in other related areas should also be taken, such as those in the intermediate slideway, the connecting rod pin, and the crankshaft bearings, for reference.
The clearance between the large and small end bearings is normal, as is the clearance in the crosshead slideways; they were just checked.
It’s very difficult to find a Japanese paper to compare the photos with. The appearance that occurs is the closest, especially in the third photo; let’s find the reason and then analyze it – deal with the first step first. I can understand Japanese.
Oil temperature, oil quality, compressor load?
The same issue with the bearings in multiple devices – it’s indeed necessary to verify the accuracy of the measurements, with another person confirming them as well. It seems there’s an issue with the measurement; it’s likely that it does not meet the requirements. For reference only.
This is caused by an excessively high local specific pressure on the bearing shells; mainly, the shaft is no longer round. If the ellipticity and conicity of the shaft journal are not eliminated, this problem will occur repeatedly.
This problem occurs repeatedly with multiple units that have had their bearing shells replaced. If the location of the damage remains unchanged, it is recommended to first check the crankshaft clearance, and also recheck the alignment of the motor and compressor