Tagged With "DE"

Topic

15MW Motor increase of X/Y Shaft vibration on DE

SimonCooper ·
Hi, monitoring is BentlyNevada 3500 with 3300 proximitiy senors we checked your sleeve bearings(vidually and by measuring) a few month ago in NonDriveEnd and DriveEnd and everything was in tolerance - did a test run coupled after recompletion -- OK now that we are running the motor again under load suddenly ond DE the shaft vibration x started to fade away from 10 to 30µm pp - no change in load or rpm. a few days later y fades away also from 10 to 30µm pp - also no change in load or rpm - no...
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Balancing of fan

vishal sharma ·
Dear all i am dealing with a RAW mill simple supported system fan 2500 kw motor with 990 r.p.m . The spectrum in DE bearing showing 1X with an amplitude 3.8mm/s overall vibration is 4mm/s in DE bearing in horizontal direction. vertical: 1.2 mm/s Axial: 1.4 mm/s but at NON DE side bearing we are having 5mm/s overall vibration in horizontal direction. the spectrum in NDE bearing showing 1X with an amplitude 3.9mm/s . vertical vibration is :1.8mm/s Axial: 2.4 mm/s by doing time wave form...
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Cement mill VRM MOTOR 5500KW DE bearing inner ring crack with out any vibrtaion severity.

y@sh ·
Hello Vb experts, here i attached damaged bearing images please give some possible causes of this catastrophic failure. bearing NU1052 -installed on May 2016.......damaged on Jan 21st 2017(Running time 7 month only) we inspected vrm motor in every fourth nightly , vibration and temperature parameters are in normal condition below 2mm/sec and below 75 degrees. but on January 21st we observed abnormal sound at Motor De side so we inspected the bearing with vibration analyzer.there is a sudden...
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Double hydraulic oil pump with induction motor

Raul Rios ·
Dear friends! In the next day I will analyze a system that is composed of an induction motor of 60 hp and 1750 rpm. The motor has two DE (drive end) where two oil-hydraulic vane pumps are coupled on both sides. It's the first time I get this kind of arrangement. What should I expect in the spectra? Does anyone have experience in this type of arrangement? Is it advisable to make measurements at 100% load or 0% load? As always, thanks for your good comments! Sincerely,
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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
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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
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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
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Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
We check the bearing clearances with feeler gauge inner and outer
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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
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Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
bearing images
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Re: seal air fan (Radial Fan) Axial Vibration

y@sh ·
BEFORE ALIGNMENT
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Re: vertical pump

rgf12 ·
If you want feedback that is not just speculation please post equipment information (speed/bearings/motor info) and any data you have. There is a lot of heavy experience here but they need something to work with. In God We Trust All Others Must Bring Data.........
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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?
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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.
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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.
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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.
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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?
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Re: vertical pump

white walker ·
motor rpm=2930 30HP 22KW,amp=37 brgs=L.s=NU312C3,O.S=7312BDBC3. please find attached file of 2V spectrum.here i am geting more vibration
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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...
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Re: vertical pump

ahmed metwaly ·
I think it may be the bearing loose in housing.
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Re: vertical pump

Walt Strong ·
It may not be a motor bearing, so measure vibrations during an uncoupled run if possible. A motor bearing is easy to replace compared to a pump bearing or wear rings. Walt
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Re: vertical pump

white walker ·
suppose if there is no issue with motor bearing.what is the further procedure.if there is problem with bearing.it should effect in envlope reading.but here i didnt see this problem.
Topic

Generator Balancing Weight Location

ALI HAIDERR ·
Dear Experts, Please share any pictures of generator (~100MW) where balancing weights (Location of weights) are placed on DE and NDE for two plane balancing. Is there any ring available for placement of weights or it would be put on coupling? Regards
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Re: Primary air fan High vibration in Motor DE brg.

Rotating Guy ·
do you have TWF data? if any please provide. regards,
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Re: Generator Balancing Weight Location

John from PA ·
Make and model of generator?
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Re: Generator Balancing Weight Location

Walt Strong ·
I would not consider placing balance weights on shaft coupling for a 100 MW generator! Walt
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Re: Generator Balancing Weight Location

John from PA ·
In a machine of that size you will likely find a ring at each end of the rotor specifically designed for the addition of trial and correction weights. The ring can typically be seen and will visually present a t-slot with multiple locations at which a weight is inserted, rotated to the desired position, then locked in place with a threaded fastener. The weights are also usually specific to the make/model of the machine so you might want to check you spare parts or spare parts list in case...
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Re: Generator Balancing Weight Location

ALI HAIDERR ·
Thanks a lot
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Re: Generator Balancing Weight Location

Ron Stiemsma ·
Just a note. I have a unit that has the balance rings but no way to access them unless you pull the rotor. Consult the OEM and they should be able to help.
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Re: Generator Balancing Weight Location

William_C._Foiles ·
I am aware that people have balanced on the end rings. This is not their purpose, and this might cause a problem. I would think that a 100 MW generator would have two planes accessible, one on each end. I have crawled into a generator this size to place weights. Others, may have an access means. You may find screw weights are needed.
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Re: Generator Balancing Weight Location

rgf12 ·
" I have a unit that has the balance rings but no way to access them unless you pull the rotor"-why would anyone design a machine like that? I know some of the older GE machines you had to pull a few panels on either end to get at that the rings but to have to pull the rotor sort of defeats the purpose doesn't it? To address the original post I would not attempt to balance a TG even though I went to all the training and more than a few seminars but it's been so long since I've done anything...
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Re: Generator Balancing Weight Location

Ron Stiemsma ·
"why would anyone design a machine like that?" Good question. That may be why there were only two in the US and now only 1.
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Re: Generator Balancing Weight Location

William_C._Foiles ·
This is a good size generator but not huge by some measures. On generators of this size, I have, depending upon construction, I have crawled inside to reach the balance planes. Not all generator balance planes have T-slots. Some use screw weights.
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Re: Balancing of fan

Ralph Stewart ·
questions: (1) Is it a centerhung or overhung fan? (2) Can you show us the impacting waveform? (3) Have you tried and failed with a single plane balance or are you planning on a single plane first or multi-plane balance first? (4)The 110 degree phase on the DE, what is the 110 referenced to, a refelection "tape" position on the shaft or reference to the NDE bearing? Thanks, Ralph
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Re: Balancing of fan

vipul@cmc ·
Waht is Displacment on DE & NDE brgs. @1x vibration rpm ? What is Phase diffrence on DE brg.between H & V Directions.? Have you properly cleaned the impller of Fan ?
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Re: Balancing of fan

Walt Strong ·
"So my question is can we perform Dynamic Balancing ??" Yes, if rotor is accessible to add/remove balance weights. "if yes will we get satisfactory results?" Yes, if rotor is clean and no cracks or looseness and bearings are tight and in good condition. You should also inspect bearing pedestals/housing for loose bolts and foundation (steel, concrete, grout) for significant cracks. Walt
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Re: Balancing of fan

vishal sharma ·
1 it is centrehung fan 2. i am planning for single plane balancing but i have some doubt in fan NDE bearing. 3 phase reference 110 on DE side is w.r.t to reflection tape position on shaft.
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Re: Balancing of fan

vishal sharma ·
phase differnce is 110 degree at fan DE side from H & V FAN IS PROPERLY CLEANED NO DUST IS THERE
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Re: Balancing of fan

vipul@cmc ·
You can do single plane balancing
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Re: Balancing of fan

vishal sharma ·
BUT i see some impacts in time wave form of NDE bearing. i am worry about that and on NDE bearing phase is not stable from H &V .
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Re: Balancing of fan

Ralph Stewart ·
Your waveform looks like there is a modulation (angelfish) pattern associated with 1x. Gs are fairly low, but concern-able. Also might have several (4 or 5) harmonics of 1x in the spectrum. There may be a problem with the inner race. Can you post a few spectrums of both bearings, horizontal and vertical? What is the phase relationship between the Horizontal DE and the Horizontal NDE (for balance reasons)? Is the fan actually centered between the bearings or is the rotor offset more toward...
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Re: Balancing of fan

Walt Strong ·
A center hung rotor with wheel between bearing can be symmetrical with double air inlets or asymmetrical with single air inlet. Single inlet fans can be balanced by single plane method with care. While it would be better to fix the bearing first, it may take less time to trim balance and extend the bearing life to a more convenient outage. Walt
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

Dave Reynolds ·
WSS Many styles of centrifugal pumps, can you add more detail Most of the time, pumps have 2-3 bearings/shaft/impeller/coupling. So if you truly have a 5x peak synchronous to machine running speed and you have 5 vanes on the impeller, then it is vane pass. Bearings will be non-synchronous data I also see what appears to be harmonics of vane pass, did you change impeller size recently, is there a check valve or valve in general that is stuck or not working properly? Just by "overhauling" a...
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

wss ·
The pump was overhauled as a part of routine maintenance ,there was no indication of vibration prior to overhauling. LPT was carried out on impeller during overhauling and no damages where observed also when we calibrated the rotor for balancing we found that it was already under tolerance. This are the main reasons I ruled out vane pass. This horizontally mounted centrifugal pump acts as a overhung rotor,having a bellow in the suction side and connected to motor using a flexible...
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

Rotating Guy ·
WSS spectrum wasn't sufficient enough for analysing, if you could provide enveloping and TWF will help to know what is fault. try to run motor alone and gathered the data and check if this frequency arise. regards,
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

Dave Reynolds ·
The pump was overhauled as a part of routine maintenance ,there was no indication of vibration prior to overhauling. ok, then it should not be vibrating now right....then something changed...is the pump running backwards, just because the valve handle moved does not mean the internals moved, did something fall/collapse and block pump inlet, are flows and pressure normal, did you change impeller size I assume "calibrated" means balanced the impeller This are the main reasons I ruled out vane...
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

wss ·
Thank you guys for your reply.The pump is at site and we are service contractors.So is it safe to conclude that occurrence of vibration is not due to any wrong procedure in overhauling (ie. balancing,Replaced bearings and gasket,mech seal test)? Please note we had changed the bearings too.
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

chary tatta ·
Greetings team Very Interesting case. only 5X dominating. No problems noticed in spectrum. All unique components are in good condition. 3.84 mm/s at 5X is still in normal condition. However, the cause of 5X dominant can appear due to flow conditions like impeller stall. Check the pump suction and delivery valves, system flow conditions (full flow or throttled flow) Load on motor etc., Pleased to see such isolated case. regards Chary
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

wss ·
Dear Mr.Chary, Its 4.8mm/s now.We are planing to take it down once it peaks over 5.5mm/s and give a check of the valves and other flow condition.The check valve on discharge line is normally on full open or full closed condition.
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Re: Vibration at 5X NDE AND DE V for Centrifugal Pump

chary tatta ·
GREETINGS WELL NOTED. THANKS FOR YOUR FEEDBACK. PLEASE FOLLOW THIS METHOD AND TRY HOW YOUR VIBRATIONS ARE INDICATING. 1. CLOSE DISCHARGE VALVE AND START THE PUMP AFTER FEW SECONDS AT FULL SPEED AT MAXIMUM PRESSURE MEASURE THE VIBRATION SLOWLY OPEN DISCHARGE VALVE AND MEASURE THE VIBRATION. IF FLOW INCREASING TIME VIBRATION RISING IT IS RELATED TO FLOW SURGES CAUSING THE VIBRATION. IF STEADY AT EVERY DISCHARGE VALVE POSITION THEN THE VIBRATION IS NOT FLOW RELATED. ALSO TAKE RUN UP AND COAST...
 
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