Skip to main content

Tagged With "shaft"

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...
Topic

23 MW Steam Turbine Generator set - High Shaft & Casing Vibration on Generator Front Bearing

vipul@cmc ·
Rated RPM : 3000         Test RPM : 2500 ( No load , Without Excitation ) MW  Rating : 23  ( Russian Make ) Critical Speed : 1590  to 2100 Types of Bearings :  Journal Bearings Problems : (1)High Shaft Vibration on  Generator Front brgs. ( No.:3) ( Trip Value 180  Microns p-p)  machine tripping @  2600-2700 rpm taking while trials  (2) High Casing Vibration on  Generator Front brgs  10  mm/s...
Topic

agitator spare shaft storage

vikramdeeps ·
Hi guys,   I want know the storage instructions for agitator spare shafts,in my case it is 9000mm long,and diameter is 200mm. Usually my past exp we used to store agitator shaft indoor in flat surface. Anybody share their storage instructions for...
Topic

best way to cbm of low speed shaft

aziz58 ·
dear all i am looking practical approch and vibration analysis technique for low speed shafts. pls share your experience. best regard
Topic

burn shaft of electromoror

aziz58 ·
dear all we face with the case of burned shaft as we done  change bearing of electromotor suddenly . the motor work as driver of fan with pully and belt. that is 3 phas ,200kw,and 1450 rpm.i attached picture of burn spot on the shaft. i would like have your opinion .we did'nt saw electrical defect .and motor ran correctly . what did happen for shaft?   best regard
Topic

Broken Gear Shaft

Jenish ·
Dear Experts, Can anybody give any expert opinion about this Broken Shaft? It is from a stand gearbox of a rolling mill..
Topic

Cement Mill Maag Gear High Vibration & Sound

Garry Kristen ·
Hi, Found Abnormal Sound And Vibration from Cement Mill - Maag gear Input shaft Drive Side and NOn Drive Side also. Guys Please try to help me to sort out the actual reason for this vibration. Motor Drive Side: 2.3 mm/sec Horz Shaft Input Side: 10.52 mm/sec Horz Type: MAAG Gear LGD-32 , Motor 4552KW and 996 RPM I have attached all spectrums for your reference
Topic

Coupling hub OR shaft run out

vikramdeeps ·
Guys , While measuring run out on hub ,,How to confirm the run out is due to shaft bend OR coupling hub problem?
Topic

Frequency for cardan shaft failures?

Alvin MC ·
Anybody here familiar with defect frequencies for cardan/Universal joint? Thanks
Reply

Re: Shaft Center line Plot

John from PA ·
Interpreting a shaft centerline (SCL) plot can be a challenge and that is the reason it should be used as "secondary" information. In other words, we would not likely recommend an action solely based on an SCL plot. If however, we have other evidence of an issue, say for example a figure 8 shaped orbit, then we would use the SCL plot to support a conclusion of misalignment. In addition, it is highly recommended that shutdown data be used for the plot generation and appropriate reference data...
Reply

Re: Shaft Center line Plot

Reliable Analyst ·
yes I agree that the truncation in Orbit TWF is very minor, and even FFT is showing about 4 harmonics, I suspect it wouldn't be a full annular rub but might be a partial rub. As trending is concerned, the 1x offsets by 5-7 microns in each startup but remains stable during operation, we are going to have an annual outage shortly and we need to plan that what activity should we execute during outage to eliminate this pre-loading, what could be the reason of preloading is a major concern, I...
Reply

Re: Shaft Center line Plot

vibramac ·
My questions: Are the X/Y probe orientations correct? Is the SCL behaviour the same on each start up? What is the behaviour of SCL on run downs? If brg is adjacent to Cpl what type of Cpl? Brg type?
Reply

Re: Shaft Center line Plot

Reliable Analyst ·
X/Y orientation is correct, need to review the previous startups & run downs, yes the brg is next to coupling, cplng is gear type, driven by increaser gearbox output, the bearings are journal brgs, rpm is 10,000. The behavior of Compressor B ( its standby) is quite normal that SCL raises in direction of rotation and while loading it lowers but follow the same track it used to rise, i.e. SCL without any abnormality.
Reply

Re: Shaft Center line Plot

John from PA ·
When was the last time you inspected the gear type coupling? At 10000 RPM it is likely continuously lubricated but if there is any sludging going on that that might be causing some forces on the shaft.
Topic

Generator Shaft wear where the bearing sits.

Claudiomag ·
Good day! im trying to understand or find a root cause for the type of wear presented on a generator (Cantarey CR20 C6 double fed induction generator 2000KW). The wear is located directly on the shaft were the bearing sits. This generator vibrates a lot and we cannot make it work due to high noise and vibration. it kept braking the encoder. Thank You very much.
Topic

GE frame 5 MS5001P Load Gear Quill Shaft Axial Movement

FSX ·
Hi every one We have a GE frame 5 Gas Turbine MS5001P coupled to Generator through reduction gear. Reduction gear is double helical. Pinion is coupled to turbine through gear type load coupling. Bull Gear shaft is hollow and a quill shaft is inserted in it. Generator Rotor is coupled to bull gear using quill shaft. Quill shaft has integral flange at generator end which is bolted to generator rotor flange. At the other end quill shaft has splines on outer dia and a hub with splines at inner...
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Do you know tooth numbers for every stage? Can you post spectral data?
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
Mr. John I have attached the all spectras above you can see. I know the teeths of all gears,
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Is it just your secret?
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
Not secret, shaft-1 = 38 shaft-2 =79, 21,21 shaft-3 = 71, 31 shaft-4 = 71, 31 shaft-5 = 286 mill speed= 15.3 rpm motor= 995 Kindly help me to resolve the issue? u need further anything i can provide
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Is this the same gearbox you asked about almost a year ago? See https://www.maintenance.org/top...-vibration-and-sound . Even if the same or different gearbox I would have the same question today as I did back then. See my reply at in the reference thread at 2/5/1710:04 AM.
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
No Mr John, This is another,
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
What exactly is this "super bolt" you make reference to? I noticed that this machine has a relatively complex foundation (again, view the video) I believe designed to provide load sharing at the girth gear by providing mount flexibility. Have you checked all the various fasteners for proper tightness in the foundation. Lastly, what exactly makes you think the vibration is high? Does the OEM (Maag) provide specific recommendations.
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
I daily check the vibration on all four superbolts and base, i find high vibration on bolt 1 as compare to other threes. there is also high vibration on concrete base upto 20 mm/sec on vertical direction near to superbolt. vibration is directional mostly on vertical on all shafts points. I think Damping within the system deteriorated causing a shift in the natural frequency to coincide with the fault frequency so vibration amplifies,the system stiffness might have changed. all the superbolts...
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
You are nearing the end of my patience! Please read everything I post and try to answer all my questions. I will repeat...what are "superbolts" Please see attached image.
Reply

Re: MAAG Gear LGD-32 High Vibration

Walt Strong ·
John, Just Google "superbolts" They are basically a ring of small bolts around the head of a large bolt. It requires incremental torque on each bolt to achieve full torque of the primary bolt shank. Walt
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Hmmm, I'm used to calling them multijack bolts. It does sound as if some foundation deterioration has been going on. You mentioned tightening these bolts a week earlier; "all the superbolts are properly tightened a week before, all grouting bolts are also tightened." Do you know if bolt #1 required any unusual tightening as compared to the other bolts?
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
I think I m just wasting my time here, people dont know what is superbolt
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Unfortunate you feel that way. I didn't know what a superbolt was, and specifically asked that question, and you failed to answer. Walt Strong pointed me to an answer. I happen to call these devices a multijack bolt, somewhat more generic as opposed to a trade name. You have not been forthcoming in your answers. When I asked "Do you know tooth numbers for every stage?" you replied "I know the teeths of all gears" but didn't give the actual numbers until I made a 2nd request. When I asked...
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
You are also failed to provide me any technical answer regarding my post, I have attached all things here for a reference, You are a complicated person, same post i have upload on another pages and I got better suggestions.
Reply

Re: MAAG Gear LGD-32 High Vibration

Ralph Stewart ·
I just today read your post. I have a question or two, if you do not mind. Other than the 165 degrees phase difference in the base plate and the concrete, did you see any actual movement between the base plate and the concrete? Was there any phase difference in the #1 "Supperbolt" and the plate vertically? I think you said the #1 Bolt had 7 mm/second movement vertically. I am wondering how the bolt would move in the vertical direction without everything moving? Did we check the plate...
Reply

Re: MAAG Gear LGD-32 High Vibration

Akhil Rathore ·
Rizwan I dont know why but i am unable to open the files you have attached still I have seen a case where the mill was having 2 drives the lifting & the pressing when any of the motor of mill 1 was taken out for maintenance the vibration level in a similar mill close to it sharing same foundation was highly affected & went high so there could be the possibility but Cement mill center drive using a MAAG gearbox must be close to max 10 years old & that is not a long period for...
Reply

Re: MAAG Gear LGD-32 High Vibration

Garry Kristen ·
Akhil, thanks we have seen there is nothing any damage or looseness in superbolts.
Reply

Re: MAAG Gear LGD-32 High Vibration

John from PA ·
Hmmm...Rizwan Sulehri, the original OP has now become Takamol and is using the logo of a US firm as an avatar. Are you now employed by Vibration Analysts, Inc? http://www.vibrationanalysts.com/default.asp
Reply

Re: MAAG Gear LGD-32 High Vibration

Ralph Stewart ·
Maybe that is why my questions were never answer, huh?
Reply

Re: High vibration in ID Fan bearings

Becar ·
2,5 mm? Is that real? You should talk around 0,1 mm. Replace the shaft as soon as possible to prevent catastrophic failure. And yes, you can clearly see increased mechanical looseness in your spectra.
Reply

Re: High vibration in ID Fan bearings

Jenish ·
Sorry it is 0.25 mm. Is it worthy doing shaft repair?
Reply

Re: High vibration in ID Fan bearings

Becar ·
Yes, I think regarding spectra your situation is critical. You should compare new shaft price with repair price and then decide.
Reply

Re: High vibration in ID Fan bearings

Walt Strong ·
Why wait and ruin the shaft? Check tightness of bearing housing bolts, especially top compression bolt, and also base bolts. Shut down and roll out the bearing to inspect bearing surface and shaft surface. It is far cheaper to replace bearing (or rebuild) than to replace shaft. You cannot rely on the vibration data (casing accelerometers) to diagnose shaft damage with journal (fluid film) bearings, but it can indicate that action is needed. Walt
Reply

Re: High vibration in ID Fan bearings

Ngo Dinh ·
I agree with Walt. You could not just base on spectrum to define the level of damage and solution. Should confirm that 0.25mm is really a problem in this case?
Reply

Re: High vibration in ID Fan bearings

Akhil Rathore ·
The rpm from spectrum is 646 not a high rpm machine. what is the motor Kw & fan bearing numbers?
Reply

Re: High vibration in ID Fan bearings

Jenish ·
Thank you all for the suggestions.. The Motor is 1300KW and the Fan bearings are 22236.
Reply

Re: High vibration in ID Fan bearings

Akhil Rathore ·
22236??? Taper bore or cylindrical bore?
Reply

Re: High vibration in ID Fan bearings

Walt Strong ·
My previous comments were based on the incorrect assumption that the fan had journal bearings. A tapered roller bearing should not have any clearance between bearing and shaft! There are metal spray techniques that are used to repair a worn shaft. I cannot make a recommendation for what works well, but I suspect a good result is in the hands of the craftsman. I only see the attempted repairs that do not work well! Perhaps this search will be of help:...
Reply

Re: High vibration in ID Fan bearings

Ngo Dinh ·
Uhum, like Walt, i comment with assumption of using journal bearing. for roller bearing, I think that the repair should be applied for this shaft. HVOF could be a solution, i used to apply and the result is good. I am not sure the price in your country but i think it is cheaper than the new rotor.
Reply

Re: High vibration in ID Fan bearings

Jenish ·
Thanks Walt and DINH, We already got some quotations for shaft repair .. It is around 20,000 USD..
Reply

Re: High vibration in ID Fan bearings

DBTCMP ·
I'm sure a more catastrophic failure will be 3,4x that cost.
Reply

Re: High vibration in ID Fan bearings

GilesG ·
One of the points about mechanical looseness that is often overlooked is that it applies to the whole system; machine, foundation, anchoring system, and grout. A failure in any of these elements will almost invariably show up as "looseness", and no amount of shimming, tweaking alignment, etc will work until the basic issue has been resolved. Check your anchor bolts, grout, and concrete integrity.
Reply

Re: High vibration in ID Fan bearings

Accelo1 ·
Conversions are .010 thousands and 1760 HP. Did they pull the bearing to get these clearance numbers? I'll guess they did and put on a new bearing at the same time. Highly likely the shaft is chewed up and this is number is maybe an average at best, certainly could have more clearance because worn shafting is difficult to measure accurately. The bearing OD should be measured and compared to the housing bore. Use the new bearing and plasti gauge if you have to. Often when the bore is shot it...
Reply

Re: High vibration in ID Fan bearings

Walt Strong ·
It might be good to replace bearings and housing (if suspect) when shaft is repaired. This would be starting on a fresh mowed playing field! Replacing or repairing only one part when other connected parts are not in good condition can have expensive consequences! Walt
 
×
×
×
×