Issues related to vibration – seeking advice and discussion
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1. In large-scale machinery, how can one determine the harmonic order based on speed and vibration frequency? And further, how can it be determined what fault is causing the issue? ? ? ? ?
There are several experts here, so I’ll start by sharing a few thoughts to spark discussion. Firstly, frequency doubling can only narrow down the possible causes of the problem; it does not necessarily lead to identifying the ultimate cause. For example, in the case of a 1X frequency multiplication where the vibration level is high, it could be due to rotor imbalance, misalignment, or rubbing; to determine the exact cause, more vibration characteristics such as the time-domain waveform of the vibration are required ； Secondly, determining the cause of the problem through the frequency-doubling characteristic involves rigorous calculations in theory. But that seems to be very complex; ordinary people can’t understand it. However, some information has been well summarized; for example, a 0.3-frequency component usually indicates oil film oscillation, while a 2-frequency component generally points to issues with the coupling.
It’s simple to determine the frequency in revolutions per minute; you just need to use frequency divided by revolutions per minute. However, it is often difficult to determine faults based on frequency components, as there is no simple one-to-one correspondence between faults and frequencies.