A new method for crankpin bearing fault diagnosis based on dynamic pressure simulation and condition monitoring

摘要

Connecting rod is a crucial part of the reciprocating compressor and the crankpin bearing fault of connecting rod is always the obstacle in fault diagnosis. Normally the condition monitoring of connecting rod and dynamic analysis are based on cylinder dynamic pressure monitoring which is also an important method for fault diagnosis. However, it is hard to diagnose crankpin bearing fault in realistic when it comes to the reciprocating compressor unfit for installing pressure transducers because there is no indicator hole or the pressure is too high. In this paper, a new method is presented to deal with above problems. The theoretical three-dimensional models of cylinder and valves of the experiment platform are established to finish the numerical simulation of dynamic pressure which has been compared with the actual measured dynamic pressure signals. Dynamic analysis of crankpin bearing with actual fault is applied to find out the abnormal impact phases. Contrasting results show that actual vibration impact phases are consistent with those of theoretical calculation. The realistic fault maintenance finally confirms the effectiveness of the new method.