Tagged With "axial"

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0.6 pk IPS High Vibration at Large Axial flow pump

Ayaz Ahmed ·
We are facing high vibration an axial Flow Morris Type 54” MPAF pump which is designed for re-circulation of Caustic Liquid. This is an overhung design pump with no bearing support on the Non drive end side and pump is directly installed to elbow of a large pipe. Following are the specifications of equipment Flow: 20,000 m3/ hr. RPM: 242 Driver: 1185rpm, 530 kW Motor Driven through a Gear box and universal coupling Observations:- Highest Vibration at P1H (Pump Inboard Horizontal) of 0.5-0.6...
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Axial End play limits for motor provided with ball bearings

vikramdeeps ·
Hi Guys, Can you help me with Axial End play limits for motors provided with ball bearings.Any standard which says the limits for end play for motors?
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Balancing duel rotor variable pitch axial fans

John.OGE ·
We are a coal fired power plant and one of our units has large duel rotor variable pitch axial fans for Induced Draft made by Westinghouse. Does anybody know balancing experts (SME) that are familiar with these kind of units?
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High Rms @ x1 Axial

P.Dunk ·
Guys/Girls if i could ask for some advise that would be a great help. I am pretty new to vibration analysis and i have come across what i think is a high reading taken from the axial position on the drive end bearing of a Kato 1540Kw Generator. From...
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High vib. on gas turbine generator NDE bearing at axial direction

chemical ·
Dear all. I am Vivek mechanical engineer. I found this website as I am facing a problem. I have a 105 bar back presser gas turbine    And  12.5 MW -11 kv generator   Here I start from beginning that we done a turbine overhauling...
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high 4x T.S. amplitude in a timken bearing

stevenlee ·
I am having trouble figuring out what this high amplitude 4 x t.s. in the axial plane is from. I have had this problem with Timken bearings before always in the axial plane sometimes it is very high in amplitude. Could it be from the housings or the...
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High axial vibration at 18x in a flowserve pump electric motor.

Alvaro Loayza ·
Hello, I have 10 identical flowserve water pumps. They are driven by a 1620 HP ABB electric motor. In 9 of these pumps I have very low amplitudes of vibration in every direction at electric motor. (0.3 -- 0.5 mm/s) I supposed this is because of system stifness But in one of them, specifically in axial direction I have very high levels of vibration (7.1 mm/s at exactly 18x) This shafts turns at 1180 RPM. So frequency is aproximately 21200 CPM. This vibration is higher (7.1 mm/s) as close to...
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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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Head scratching high axial vibration

Chris184 ·
I had a high axial vibration in a 1000hp 4 pole 2300VAC motor. It had some issues with the bearing housings and after they were reworked in the machine shop a second time and a rub cured there still remains a puzzling high axial vibration that is at...
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How to set Magnetic Center of the motor

Engr Jamil ·
We are having one motor for maintenance 3600HP, 6.6KV, 3582RPM. In Solo testing it shows the axial movement of the rotor shaft around 1.3mm back and forth which must be stable in the magnetic center line. We are facing axial vibration 5.5mm/sec and radial around 3mm/sec. The vibration is fluctuating form 1.7 to 3 radial and 2.7 to 5.5 axial. How can we adjust the magnetic center to keep the rotor stable. Also what is the acceptable unbalance for power source because we are having almost 10%...
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Motor running in offset from magnetic center

Abhi03 ·
Dear All, We have facing a issue with one HT motor with axial fan load. When we start the motor (consider the motor has stopped in offset from magnetic center) it continues to run in offset up to rated speed (996 RPM) condition without trying to attend magnetic center. However when we reduce the speed bellow 500 RPM it comes to magnetic center and continues to run at magnetic center. The motor is designed with floating bearing and load DE side bearing is axial guide bearing. The motor rotor...
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Motor shaft axial movement solo run

vikramdeeps ·
Hi Guys , Usually I have seen axial movement in motor shaft during solo runs but I am curious to know that How much axial movement is allowed in solo run in motors with sleeve bearings and anti friction bearings?   Guys Usually I have seen...
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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
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Vibration Tri Axial Sensor Mounting

Avinash Thawani ·
Hi, What are the pros and cons of RAT vs VAH scheme RAT is Radial Axial Tangential VAH Vertical Axial Horizontal Which one is better for Triaxial
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Re: Balancing duel rotor variable pitch axial fans

arie mol ·
Over the recent 25 years I have balanced many of these MWatt Industrial fans worldwide. Do you face a specific problem?
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Re: Balancing duel rotor variable pitch axial fans

John.OGE ·
This fan has proven difficult to balance. Not many plants use a two stage variable pitch axial fan. The specific fan is a Westinghouse Sturtevant Two-Stage Induced Draft Axial Fan (885 RPM, 7000 hp, hydraulically actuated blade pitch). Have you balanced similar types of fans?
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Re: High Rms @ x1 Axial

Edwin de B ·
Do you have any comparison with previous values or other simular equipment? Diesel engines can generate high vibration without anything wrong. If there is an increase in axial vibration, especially 1X and, as i see in your spectrum, harmonics of it, you should check the alignment and if the coupling rubber got hard by aging.
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Re: High Rms @ x1 Axial

P.Dunk ·
Hi Edwin firstly thanks for your response. I have done 5 other generators which are the same. Same mount arrangement same load etc maybe 5-6 rpm difference. I am getting Rms values ranging from 5.223 being the lowest to 6.612 the highest which all seem to be consistent. It just got alarm bells ringing in my head with the high reading of 8.41on the generator which is basically an emergency back up generator with the least running hours on. I have initially advised alignment checks to be...
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Re: High Rms @ x1 Axial

John from PA ·
I'm not sure about the Vulkan coupling but on a competitor type of coupling in a diesel driven test stand application there was some recommended maintenance in the form of application of a rubber lubricant. We used to do this every six months. It was a relatively simple task that involved unbolting a plate and spraying rubber lubricant on the rubber blocks. It might be worth checking if the Vulkan has a similar maintenance procedure.
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Re: Balancing duel rotor variable pitch axial fans

arie mol ·
John, Have you balanced similar types of fans? No for Westinghouse. Yes for Howden, fans were made in the Netherlands and Denmark. In coal fired plants. Problems encountered that will make balancing troublesome: * Loose parts in hollow impeller hub(s). Solid stuff like corrosive settlements of pitch control lub oil leakage into hub. A repeated initial run proves such unbalance instability: different amplitudes and/or phase angles for both runs. Clean hub first. * A resonant condition near...
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Re: High Rms @ x1 Axial

zhouyh ·
I see many 0.5 x harmonics, which diesel engine produces.
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Re: High Rms @ x1 Axial

Ron Brook ·
P Dunk, You are suggesting the two best causes for an elevated axial on a Kato gen set. Usually the lowest of the vibration readings. Ron Brook
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Re: high 4x T.S. amplitude in a timken bearing

Nockingroll ·
hi stevenlee you didn't mention what equipment this is......maybe a 4 vane impellor pump?
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Re: high 4x T.S. amplitude in a timken bearing

Vibmaster ·
What is the bearing designation?
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Re: high 4x T.S. amplitude in a timken bearing

seandude ·
I start by asking myself- What is bouncing against my sensor 4 times each revolution? What do I have 4 of in this machine? A 4 jaw coupling? 4 impeller vanes in my pump? 4 blades on my fan? I see M's and W's in the waveform. There is definitely misalignment happening, but I need more information about the machine before I could give you better guesses. Please post your root cause and solution so everyone can learn.
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Re: high 4x T.S. amplitude in a timken bearing

stevenlee ·
This is a reel spool from a paper machine it is in the balancer at our shop. For some reason this roll had excessive axial vibration and I cant think of any reason there would be a high 4 x t.s. other then some form of misalignment or cocked bearing. Any help would be appreciated thanks
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Re: high 4x T.S. amplitude in a timken bearing

Edwin de B ·
Can you share a drawing or picture of the equipmnent? Could be from the coupling but that depends o the type of it.
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Re: High Rms @ x1 Axial

STEAVE ZAZOU ·
Dear P Dunk, you have to look on your trend,if it's increase you have to be worry,we have for 3512 gen diesel pump,rms is on axial is 14mm/s but the trend at the begining is steady,just contunie to monitor it
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Re: High Rms @ x1 Axial

John from PA ·
Originally Posted by P.Dunk: From what i can make out i am getting my main peak at x 1 running speed and there after. I will upload the images. The generator is driven by a caterpillar 3516 diesel engine. Engine and generator are spring mounted. Generator speed is1202 Rpm. Coupling is a vulkan solid rubber spider type. I noted with interest that you state that the predominant vibration is in an axial direction referred to the input shaft. Comments (including my own) so far have been about...
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Re: Motor shaft axial movement solo run

rgf12 ·
If your motor supplier cannot provide the info I have seen a motor shop tech mark the shaft at rest then run the machine uncoupled and push the shaft with a 2x4 (gently) towards the outboard until it stops to determine total movement. I'm not sure if that is a recommended practice anymore but we were dealing with a 40 year old motor and there was no documentation to be had.
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Re: Motor shaft axial movement solo run

John from PA ·
I have seen three marks on motor shafts and been told they are the magnetic center in the middle position and the total in/out physical movement marks the outer marks. I have also been told that the center represents the "mechanical" center so what they mean in your case may be dependent on the guy marking the shaft. Having said that, in a properly manufactured or rebuilt motor there should not be much difference between magnetic center and mechanical center. Axial forces from being off mag...
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Re: Motor shaft axial movement solo run

vikramdeeps ·
Thanks John but still need some clarification that for motor with off magnetic centre is it necessary to set the magnetic centre in solo run or the motor will sets at magnetic centre by itself in coupled run, And how to set the magnetic centre in solo run?
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Re: Motor shaft axial movement solo run

Chris184 ·
My experience is you first need to run the motor uncoupled to mark the magnetic center. Sometimes you will have a mark at the outermost physical shaft position and the innermost physical shaft position. The center mark is typically the magnetic center. To set mark the magnetic center, you will need to run the motor uncoupled and on a flat surface with any guards or covers installed. If you run with only the bottom half of the end bell or without all the dog house installed, the altered...
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Re: Motor shaft axial movement solo run

Rusty Cas ·
Chris is a motor shop guy, and his explanation sounds right, given what I've seen done in the field. "The trend is your friend" MachineryAnalysis.org
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Re: Motor shaft axial movement solo run

John from PA ·
Originally Posted by Rusty Cas: Chris is a motor shop guy, and his explanation sounds right, given what I've seen done in the field. "The trend is your friend" MachineryAnalysis.org Originally Posted by Chris184: To set mark the magnetic center, you will need to run the motor uncoupled and on a flat surface with any guards or covers installed. If you run with only the bottom half of the end bell or without all the dog house installed, the altered airflow through the rotors fans can cause the...
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Re: Head scratching high axial vibration

Ngo Dinh ·
My question is " do you conduct any maintenance action before the issue happen and if any, how do you align the force center for rotor of the motor?" I focus on the evident that the high axial vibration disappear when the power cut to motor.
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Re: 0.6 pk IPS High Vibration at Large Axial flow pump

Dave Reynolds ·
Can you provide a multiple point waterfall, include HVA directions, at each bearing location on the gearbox and pump, if you can get the motor in there also that would help. 18 points maximum allowed in AMS software Resolution of your data is not sufficient enough to determine what frequencies are present, can you take a set of velocity readings on this machine with a 6000 cpm fmax, 1600 LOR, 4 avgs, 50% overlap. Also collect peakvue with 60,000 fmax, 1600 LOR, 500hz and 1000hz filters, 1...
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Re: Motor running in offset from magnetic center

Dan Timberlake ·
What make and model of coupling?
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Re: Motor running in offset from magnetic center

edisonindia ·
Looks like your fan is creating an axial thrust higher than the normal magnetic thrust to keep it in magnetic center. As long as it is not creating any vibration issues or abnormal bearing temperature rises, it is not a problem.
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Re: Motor running in offset from magnetic center

electricpete ·
A sleeve bearing motor (uncoupled) has it's own range of motion between two limits. These limits are established by shaft shoulders contacting axial face of the bearing… these surfaces are not designed for continuous axial contact and someitimes are called "thrust bumpers". After you the motor to driven equipment, there is new narrower range of motion established by driven equipment axial thrust bearing, allowing for thrust bearing clearanace, coupling endfloat, and possibly thermal...
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Re: Motor running in offset from magnetic center

electricpete ·
Sorry, I didn't see Edison's comments. I agree with him also. My post added some cautions about loading the thrust bumpers because op doesn't completely explain what the condition is.
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Re: Motor running in offset from magnetic center

Abhi03 ·
@Dan, Its a pin-bush coupling with axial backlash limitation. @EDISIONINDIA Thanks a lot for your feedback. We also though for the axial thrust issue but we are worried that it should not damage the bearing axial collar. Also how do we show customer its from the load side that the issue is coming up and what corrective measures should we take? @ELECTREPETE Thanks for your inputs ELECTRIPETE. We are worried for the same issue that it should not damage the bearing axial collar. Any corrective ...
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Re: Motor running in offset from magnetic center

electricpete ·
A coupling used with a horizontal sleeve bearing motor has to be be able to limit travel beyond a certain point in both directions (in order to prevent motor from hitting thrust bumpers). I haven't heard of pin and bush with axial backlash limitation. Examples of pin and bush couplings that is unsuitable to limit endfloat: http://www.vibispa.com/en/pin-and-bush-couplings.html http://www.industry.siemens.co...ing/Pages/rupex.aspx Do you have more details on your specific pin and bush...
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Re: Motor running in offset from magnetic center

edisonindia ·
Mark the coupled running position on the shaft close to the bearing housing with a marker pen. Stop the motor. Rotate the rotor manually to bring it to the marked running position. Open both side bearing tops and measure the shaft shoulder clearances. A minimum of 2 mm shoulder axial clearance is required to prevent bearing rub though ideal will be equal clearances on both sides of the shoulders for each bearing.
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Re: Motor running in offset from magnetic center

Dan Timberlake ·
Here is a theory that I think explains all the symptoms you have described. In other posts it has been determined that the forces a rotor exerts trying to return to mag center are pretty small. In order for the motor to reach its magnetic center the coupling would have to be VERY slippery or flexible axially. Maybe gear type couplings operating at sufficient angle to be in the hydrodynamic range are slippery enough. Elastomer couplings, machinery mounts, etc, in order to be lubrication-free,...
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Re: Motor running in offset from magnetic center

VibeMan81 ·
I think as ELECTRICPETE points out, its probably not a problem. Dans explanation makes perfect sense to me as well. "A lot is possible. But most of the time a little is sufficient."
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Re: Motor running in offset from magnetic center

Abhi03 ·
@ELECTRICPETE ... coupling is Flender rupex RWN Thank you EDINSONINDIA @DAN.. Thank you DAN.. This sounds convincing we will inspect the coupling and check for any rubbing marks..
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Re: Head scratching high axial vibration

Chris184 ·
Originally Posted by Ngo Dinh: My question is " do you conduct any maintenance action before the issue happen and if any, how do you align the force center for rotor of the motor?" I focus on the evident that the high axial vibration disappear when the power cut to motor. Did you see the bump test at the end of the last page?
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Re: Head scratching high axial vibration

LNG Vibe ·
Chris 184, I think you are on the right track focusing on the BPFO disappearing when power is cut. It would appear to me 2XLF is a forcing frequency of possibly the BPFO or a natural frequency based on your bump test. I have seen modulation in the wave form and high axial like that before on sleeve bearing motors when they are pulled off mag center due to an incorrect coupling gap. Also if the motor is uncoupled and the cooling fan will pull the rotor off mag center. But since this has...
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Re: Head scratching high axial vibration

Chris184 ·
Originally Posted by LNG Vibe: Chris 184, I think you are on the right track focusing on the BPFO disappearing when power is cut. It would appear to me 2XLF is a forcing frequency of possibly the BPFO or a natural frequency based on your bump test. I have seen modulation in the wave form and high axial like that before on sleeve bearing motors when they are pulled off mag center due to an incorrect coupling gap. Also if the motor is uncoupled and the cooling fan will pull the rotor off mag...
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