Tagged With "sec"

Topic

seal air fan (Radial Fan) Axial Vibration

y@sh ·
hello guys, help me out from this problem the radial fan getting 7.6 orders and its harmonics . high vibration on axial side 17 mm/sec .fan have 11 no.of vanes and that 7.6 orders matching with bearing outer race but after checking the bearing outer races are normal and inner race clearances was 0.3 mm. i am unable to identify the this problem please,help me guys
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Walt Strong ·
" that 7.6 orders matching with bearing outer race but after checking the bearing outer races are normal" You have outer race fault frequency with 1xSS sidebands (modulation), so it sure looks like an outer race fault! How did you or someone actually "check the outer race"? Most bearings require destructive disassembly (cut apart) to actually see the full bearing race surface. Don't get lost in a pile of data! Walt
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Shurafa ·
Were these spectra collected before after the "bearing checks"? Did you replace the bearings or you reinstalled them? It looks there is a bearing defect. Regards-Ali M. Al-Shurafa
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
Above spectrums are After checking the bearings and alignment and we find inner clearances but there is no outer race defect physically
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
We check the bearing clearances with feeler gauge inner and outer
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
We disassemble the both de and nde bearing and checked physically but there is no Outer race defect
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
bearing images
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
BEFORE ALIGNMENT
Reply

Re: seal air fan (Radial Fan) Axial Vibration

electricpete ·
[quote] inner race clearances was 0.3 mm.[/quote] Can you explain more about this measurement? I hope it is not between bearing and shaft (that should not be clearance) What style bearing is it?
Reply

Re: seal air fan (Radial Fan) Axial Vibration

montaser ·
I advice you to make mark using (correction pen) between the bearing outer race and lower part of housing and another mark between bearing inner race and shaft, and keep the fan running for some hours, then stop and inspect the marks position for the possibility of bearing rotation inside the housing.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
Tnq for reply its not b/w shaft and bearing ,clearances are b/w balls and bearing inner ring.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
thank you sir but it is a heavy equipment . so,it's impossible to open the machine at present conditions.
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Jim1 ·
Oil filled housing? Did you sample the oil? What caused the satin finish on the rollers and inner raceway?
Reply

Re: seal air fan (Radial Fan) Axial Vibration

Walt Strong ·
Y@SH, I looked at your three photos. None of the photos show the surface of the outer race/ring that is in the contact path of the rollers. The bearing would have to be destructively taken apart to do so. Therefore your limited inspection does not prove or disprove an outer race defect. The only way to do that would be to remove the grease and cut the bearing rings apart. You can save that activity for a later date when you change the bearing. If you actually put in new bearing when those...
Topic

1600 kW 3 Phase AC motor axial vibration

Mukesh Chandrawanshi ·
I have face a new vibration problem in 1600 kW AC motor which is associated with fan. in this equipment vibration is high in vertical & Axial direction in motor Drive End & Non Drive end vibration is more than 3.5 mm/sec in axial direction whereas horizontal vibration is 0.85 mm/sec. Motor has 8 pole , and that time running rpm is 337.5. Wondering is that we found a peak in vibration signature at 30337.5 cpm and amplitude value is 3.20 mm/sec . also find side band of 6.25Hz (337.5...
Reply

Re: 1600 kW 3 Phase AC motor axial vibration

Shurafa ·
If my calculations are correct this time, the high amplitude is at a high frequency: 90x. The sourse of vibration might be related to rotor bars or stator slots. Can you check these specifications from your books? Have you done a shutdown test to observe the effect of cutting the electric power on the vibration? I guess the input from the forum members would more if you can post some vibration plots and more motor details. Regards- Ali M. Al-Shurafa
Reply

Re: 1600 kW 3 Phase AC motor axial vibration

Ayaz Ahmed ·
Additionally, can you see 1- 2xLF sidebands across this 90x peak. 2- PPF sidebands around 1x and first few harmonics.
×
×
×
×