I'm facing High vibration issue in my FD fan. The attached excel sheel have all the details.
Maintenance History- Before PM the vibration of Fan DE was normal, But after PM high axial vibration observed at fan Driving End. I don't have spectrum of that as i was on leave , so my maintenance department decided to change the bearing. But after Bearing change the vibration problem was not resolved. SO they waited for me to come. So when i came i saw that Horizontal vibration levels was increased so i did balancing. AFter balancing H and V direction vibration reduced but not Axial. It was still coming above 6 mm/sec but it increased to 7.2mm/sec while loading the fan.
I observed the spectrum and felt that Fan DE spectrum is showing high BPFO in axial direction, while the acceleration is only 7m/s^2. As it is a new bearing and after analyzing i felt that the bearing is under heavy preload and is not properly mounted on shaft and housing thus yielding high BPFO in axial direction. So i increased the bearing clearance to 0.08mm and interference to 0.03. checked skewness of bearing and found nothing. Levelling check of Fan DE to NDE done with master Leveller. After doing all these i started the but no success. The High axial vibration is still there.
fan DE-22224 E K C3
Fan NDE- C 2222 E.
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