Tagged With "shaft"

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Shaft centerline plot of motor bearings

Yasaswy ·
Hi everyone, So I have a high vibration issue in an horizontal induction motor with sleeve bearings (coupled to a BFW pump) which is 3.5 MW and provided with proximity probes. The vibration amplitude is very much less than the alarm limits but are in an increasing trend which is my concern. I have a query regarding the shaft centerline plot. Now let us say the bearing clearance is 0.2 mm. Now during a start-up (or a coast down) I was looking at a shaft centerline plot and the vertical axis...
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NEW VibrAling- Laser Alignment- Hog Shaft for sale!

Raul Rios ·
For Sale. Totaly new. Price: US $ 4,125 Can write by mail: ensayospredictivos@gmail.com
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Frequency for cardan shaft failures?

Alvin MC ·
Anybody here familiar with defect frequencies for cardan/Universal joint? Thanks
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Horizontal Shaft CL movement only on Steam Turbine Governor End

Jonston ·
Recently witnessed a leftward horizontal shaft centreline movement of 130 um during low load operation of above 40MW extraction condensing Steam turbine. This movement happened on on governor or steam inlet end only. Bearing metal temprature increased from normally seen 80 c to max 120c but came back to 99c. Currently at full load shaft position is still maintaining on left ward pad and radial vibration has subsided from 10 microm to 5 micron showing suppression by vaccinity to the clearance...
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Storage procedure for long shafts in warehouse

Abhishek Nagar ·
Dear all, I want to know about proper storage procedure for the long shafts of vertical pumps & turbines. I have read about vertical storage procedure but could not find any detail about it on internet. Can anyone guide me on this?
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Shaft run out on vibration

Yasaswy ·
Hi, Can shaft run out at the shaft end have an effect on the vibration? Online shaft vibration probes (proximity probes) are located at the bearing area on the shaft and if there is no run out at the bearing area but only at the shaft end does it still contribute to shaft vibration? As I understand, the proximity probes will see the bearing seating area on the shaft and if there is no run out at that location, there shouldn't be any vibration related to run out. Am I correct? Nagesh
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Shaft Centerline Movement of Overhung Rotor

DuPlesis ·
What will be the normal shaft centreline movement for Overhung Rotor supported by tilting pad bearings? Particularly with reference to a light overhung rotor, like Power Turbine Shaft in twin-shaft gas turbine driving heavier centrifugal compressor rotor. I have attached shaft centreline movements for 2 different set of machines. In one case, power turbine is driving LP and HP rotors. In another case, Power turbine is driving only 1 HP Rotor.
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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..
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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
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Threaded Impeller to shaft clearance

Yasaswy ·
Hi everyone, Can someone tell me what should be the clearance/fit for semi open impeller which tightens on the shaft threaded area? We have a overhung pump here with semi open impeller. The manufacturer has provided the impeller thread ID as 60 mm and shaft thread OD as 58 mm (a clearance of 2 mm). However he has also provided a small screw which tightens on the shaft from the outside after impeller is fitted. Is this clearance for the threaded connection normal? If no external screw is...
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MAAG Gear LGD-32 High Vibration

Garry Kristen ·
We have a problem in our gearbox related to vibration on high speed shaft both ends horz and vertical and on base bolts. Vibration transmitting to 2nd shaft ( Intermediate shaft ) also. Observed Abnormal Vibrations on Gearbox Input and Intermediate shafts, particularly on horizontal 5.5 mm/s and 7.0 mm/s and vertical 6.4 mm/s and 5.8 mm/s respectively recorded today. Also High G’s Values on Input and Intermediate shafts 2.6 g’s and 2.9 g’s respectively along with significant impacting &...
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Vibrations in hollow -shaft mounting gearbox

Rajj ·
We have one hollow shaft mounting, two input gearbox having gear ratio 14.3 to drive paper machine drying cylinder. It is pivoted at one side and driven by two D.C. motors of 210KW with cardon shafts. Gearbox has high vibration levels in vertical direction opposite to pivot end. At 750mpm ( 945 input rpm), we get max vib.at gearbox in H & A direction @4mm/sec. and 11 mm/sec in V direction opposite to pivot end. Mostly at 1Xrpm & 2Xrpm of input speed. Is it safe to run at such high...
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shaft alignment

shrestha1 ·
Hello all, Is it possible to get a literature on cayere methods being used in hydro turbine erection? How we use it in the field may be methodology with necessary instruments be more appropriate. Thanks & Regards Santosh
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Shaft Fracture Demineralized Pump

Hatop Hendra PS ·
Dear Master, I have some problem recently with demineralized pump. This pump shaft suddenly broken when weekly changeover schedule start (16 March 2019). This Pump have good vibration result (no alarm point). and running good after i do shaft alignment at 28 February 2019. Anyone have experience with shaft fracture analysis? What is the possibility problem happen causing shaft broken? Here is the Pump Spec : Centrifugal Pump Brand : Dalian Songlone Pump Q = 40 m3/h H = 50 m Speed = 2930 RPM...
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Definition of trim balancing?

abdulbasitb ·
What does the word "trim" imply when used in the term "trim balancing"?
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Odd vibration from gearbox

tcvib ·
Have an odd scenario from a reducer,  We have a 151 Hz peak that resembles gearmesh freq.  but gearbox rebuild shop information does not match for that frequency.  gear teeth counts are not conflicting.  Curious if anyone has seen this before.  gearbox is a double reduction, parallel shafts,  1192 input speed, teeth counts are 25 on HS pinion,  Int shaft has 46 teeth on the bull and 20 on the pinion,  Output shaft has 103 teeth.  This is from the...
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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?
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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...
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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...
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Shaft run out for long shaft

vikramdeeps ·
Hi, I want to check shaft run out for one 9m long and 200 mm dia shaft for agitator,currently this shaft is lying in the wooden container ,due to some improper storage,I am expecting certain bend in the shaft,so to get an idea about bend in shaft,can...
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fluid coupling mounting

alainraad ·
there is any problem if a fluid coupling is mounted in the wrong direction? the input on the gearbox shaft and the out on the motor? the coupling is flender fludex FAD 297. for me i think that there is no problem, in case that the gearbox shaft can...
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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.
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Quill Shaft for Gas Turbine Reducer Gearboxes

Kish ·
I see quill shafts have been used for Gas Turbine Reducer Gearboxes. Can someone say what exactly is the purpose of quill shaft in Gearboxes?  I have searched it in google and I haven't found what I was looking for. I don't want people asking me...
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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
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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
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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...
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Shaft Center line Plot

Reliable Analyst ·
In startup transient of natural gas centrifugal compressor, the shaft centerline raised opposite to direction of rotation, till it reached to FSNL, then compressor was loaded and shaft centerline moved down but didn't followed the track it used during rising, but moved on right side. Kindly review the attached plot & share your comment that what could be the reason of pre-loaded condition, what is the force causing it deviate in that direction. TWF is also showing some truncation which...
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motor vibration at 3XTS

Hossam 2 ·
Good Afternoon guys i have a problem related to a motor vibration which is summarized in a dominant 3XTS on motor side in the horizontal direction while 1X and 2X barely visible overhung fan variable speed up to 600 rpm coupling is flexible 14 rubber element and this rubber is new the alignment within tolerance 0.1mm while the max, allowable is 0.5 the shaft has coupling has run out problem 0.25mm and shaft has center runout between the bearings 0.3 mm and near the free bearing 1.7mm i know...
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Gearbox Bearing Failure

Alvin MC ·
What could cause an inner ring to fail like this? This is from a rotary valve drive gearbox. Gearbox is a small 37.5 to 1 ratio. This bearing was on the input shaft and you can see the hole on the shaft where it had a pin to hold the pinion gear to the shaft. The pin was sheared and broke off. The bearing cage and balls were destroyed from the failure.
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shaft looseness

Hossam 2 ·
Dear Experts what is the best way to detect the shaft wear under the bearing inner race or under the sleeve specially i face many problems like that but the only frequency shown in the spectrum is 1XTS. Example Overhung Fan variable speed motor (rated speed 1485 rpm) dominant frequency 1XTS (H=10 mm./sec....Vertical=6 mm./sec.....A=4 mm./sec) after balancing the vibration dropped to 2 mm./sec but in two days the vibration reached 36 mm./sec at horizontal direction 1XTS dominant vertical 25...
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High Slow Roll Reading on 1 Probe

DuPlesis ·
Guys, I have a Solar Titan 130 Gas Turbine. It's a 2 Shaft Gas Turbine. 1st Shaft - Gas Producer Rotor - Consists of Axial Compressor and 2 Stage Gas Turbine. Air Intake End of this rotor is connected through a spline coupling to the accessory drive gearbox. Please see attached layout image. 2nd Shaft - Power Turbine Rotor - 2 Stage Gas Turbine Discs providing mechanical drive to the Centrifugal Gas Compressor All the radial bearings are fitted with X & Y proximity probes. Slow Roll...
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High vibration in ID Fan bearings

Jenish ·
Dear Experts, We experience a problem with one of our ID Fans. The machine train is Motor - Oil Flex - Centerhung Fan. The Fan bearings are showing high vibration. Seems like a clearance issue. The clearance between the shaft and the bearing is 2.5 mm. One of the expert suggest for a shaft repair. Shaft OD at present is 179.30mm. Required is 180 mm. Shaft repair is costly and we need a second opinion. Did any of you experience similar problems? Is there any alternative? The vibration...
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shaft alignment rim face method using simple excel sheet programme

l4u ·
a simple excel sheet for shaft alignment rim face method . please note dial gauge position carefully in sheet. if put dial gauge in different position than please change + - sign accordingly
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Re: best way to cbm of low speed shaft

Dan Timberlake ·
Hi AZIZ58, CBM = condition based maintenance ? What type of bearings? What type of lubrication? What type of machinery? How expensive and critical is the equipment? What is low rpm ? That's a start. ================= Example, I think monitoring of cooling tower gearboxes ( out put rpm as low as 150 ) is incomplete without oil analysis a few times per year.
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Re: best way to cbm of low speed shaft

aziz58 ·
dear dan i want to know which vibration task analysis is useful for low speed machine (belowe1000 rpm) that are critical for us and have journal or rolling bearing. best regard
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Re: best way to cbm of low speed shaft

Beatnik ·
For Rolling element bearing=: PeakVue/Demodulation and looking at the Timewaveform is a good start. The Peakvue/demodulation must be configured specifically for the bearing fault frequencies and not the gearmesh. I agree with Dan about oil analysis.
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Re: best way to cbm of low speed shaft

aziz58 ·
thanks beatnik. can u explain more about peakvue. and what about gearmesh.because we have modulation in gear defect.
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Re: best way to cbm of low speed shaft

IrishMark ·
Peakvue/demodulation/ wont work with Journal bearings the best thing you can use there is oil analysis. Aziz58 Peakvue is a demodulation method used by 'Emerson CSI' vibration analyzers to detect bearing and gear mesh faults, but It only works on rolling element bearings gear teeth.
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Re: best way to cbm of low speed shaft

mirook ·
use longterm waveform or HFD like Envelope demodulation,SPM,peakvue
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Re: Definition of trim balancing?

Walt Strong ·
I quickly scanned through ISO standard 1940-1 and found no mention of the word. I think it's safe to say it does not define a fundamental property associated with balance. I have seen the word "trim" used two ways. One description is used to describe an additional weight that is added during balancing when the correction weight is not adequate. Typically in this case you could installing new correction weight, or you could add a small trim weight to meet requirements. The second description...
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Re: Definition of trim balancing?

William_C._Foiles ·
1940 has been updated. The balancing standards have new numbers. The old 1940 was for low speed balancing. If you look at ISO 21940-2, the definitions, you will find a definition
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Re: Definition of trim balancing?

Shurafa ·
This term is a part of the vocabulary explained in ISO 1925:2001 - Mechanical Vibration -- Balancing -- Vocabulary. According to this standard, it is usually the small balance that one would perform in order to reach the final balance condition after the main balancing target has been achieved. Regards- Ali M. Al-Shurafa
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Re: Definition of trim balancing?

Walt Strong ·
"According to this standard, it is usually the small balance that one would perform in order to reach the final balance condition after the main balancing target has been achieved." Thanks for the update on the actual ISO definition that closely matches one of the ones that I gave earlier. Walt
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Re: Definition of trim balancing?

Shurafa ·
Just to avoid a possible misunderstanding, the statement above is not the actual verbag of the standard. It is rephrased. Regards- Ali M. Al-Shurafa
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Re: Definition of trim balancing?

William_C._Foiles ·
It could be that I have referenced a draft ISO standard planned to replace 1925. I didn't check our standards site for availability.
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Re: Odd vibration from gearbox

Walt Strong ·
You have two sets of sideband frequencies for the axial measurement; what are they? " I have just discovered something no one has seen before. " I have been in this game for 48 years, and there have been no new laws of physics related to machine vibrations! Walt
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Re: Odd vibration from gearbox

John from PA ·
The input shaft axial is almost 0.9 in/sec pk while the output shaft axial is 0.06 in/sec. Is this a parallel shaft gearbox? Normally these two readings, if obtained off the casing, would be much closer to each other except for the possibility of opposing phase. What type of transducer is being used?
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Re: Odd vibration from gearbox

tcvib ·
John, I am relaying messages from the end user. I assume he is using a 100mV/g accelerometer. It is a parallel reducer. These points are taken on the casing and the gearbox is approx. 4 feet long. In the output shaft reading sidebands are at output shaft speeds and int shaft speeds! Todd
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Re: Odd vibration from gearbox

Walt Strong ·
Based on some simple calculations, the frequency at 151 Hz is 14 times intermediate shaft speed and 72 times the output shaft speed. While it doesn't match either of the two tooth mesh frequencies, the gear fault appears to be between intermediate shaft and the output shaft. As John indicated there is too much difference between the two axial measurements, so possibly the sensitivity of the accelerometer was incorrectly programmed for the measurement points or there was some other reason for...
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Re: Odd vibration from gearbox

John from PA ·
Good catch Walt! As to causes, as most know a gearbox is a beautiful device for generation of sum and difference frequencies. The 151 Hz may very well be related to sum and difference. There is also a possibility that what we are looking at is a ghost frequency. Tracking down a ghost frequency might be difficult in a gearbox of this type because few vendors document the manufacturing process of relatively low quality gearing. I'm still puzzled at the difference in the magnitude between the...
 
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