John from PA posted:
I'd have to look carefully at the data to see if there are some subtle symptoms but if I have an undersize shaft ("looseness") that also means I have a shaft that can be eccentric in the bearing bore. What does eccentricity cause? Unbalance (1X). But if the shaft is undersize to the point where it can randomly take a position within the bore, I would anticipate a different phase every time the machine is stopped/started. In addition, attempts to balance might be unsuccessful.
i have already balanced the fan two days before exhibiting high vibration ,but how should i anticipate the shaft wear specially during balancing the phase was stable horizontal to horizontal
is there a way to anticipate shaft wear , we found it 0.07 mm wear