Treatment process for the burnishing failure of reciprocating compressor bearing shells

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On November 12, 2010, the bearing of compressor 401D started to smoke, leading to an emergency shutdown. Upon inspection, it was found that the bearing’s thrust ring had burned black and contained copper shavings; the impurities were removed, the thrust ring was repaired, and then the compressor was restarted without any further actions being taken. At 10:20 on November 16, 2010, the compressor bearing started smoking again, causing the machine to stop operating ； Upon shutdown and disassembly, it was found that the situation was the same as the previous damage: the thrust ring was burned black, with copper shavings present ； After removing impurities and repairing the thrust ring, the float bearings of the motor were adjusted, and operation was resumed once installation was complete. Three days later, the bearing temperature was found to be high (59 degrees). After shutting down the machine and removing the bearing, it was observed that the upper bearing shell was in good condition, while the center of the lower bearing shell was partially blackened. After replacing it with a new bearing shell, the machine was restarted and operated normally. As a technical staff member, I was involved in the entire repair process and would like to share some humble opinions on this incident. Generally, there are 4 reasons for bearing wear: uneven fit between the bearing and the shaft journal, jamming, or too small a gap ； Bearing skew and shaft bending ； Insufficient lubricant supply ； The oil is too dirty or degraded, or other impurities have entered the bearing. During the first and second firing cycles, it was mainly the thrust copper rings that darkened and lost copper shavings. This indicates that the axial force on the unit is too high; the thrust ring is pressed tightly against the unit’s body, and the lack of lubricating oil causes the thrust ring’s temperature to rise excessively, leading to burning and smoking. We checked the magnetic center line of the motor, adjusted the floating bearing shells of the motor, and resumed operation after completion of the installation. No similar accidents have occurred to date. Analysis of the reasons for the third bearing burnout: The differential pressure across the fuel station filter reached 350 KPa, resulting in insufficient oil supply to the bearing shells. Due to the characteristic of lower specific pressure in these bearing shells, a higher oil pressure is required to achieve adequate lubrication; this pressure generally needs to be maintained between 0.4 and 0.5 MPa to ensure the proper operation of the main shaft. Therefore, insufficient oil supply was the root cause of this bearing burnout.