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Asset Condition ManagementPosts About Asset Condition Management
Overhung blower bearing failure
Registered Member http://www.fag.de/NASApp/Access/index.jsp?lang=1 Here is a link to FAG web page. Rolling bearing diagnosis would be choice to view different failure modes of bearings. It appears that only one half of the bearing was loaded, this maybe due to bearing alignment, installation technique, worn housing, bent shaft and the list goes on. If you think the damage was done by welding, then why only one race damaged and not both? Roller are touching in both races when at rest. Lack of lubrication is... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Rotor bow on centrifugal compressor
Registered Member Mr. Khan, When you say temporary, you imply that 1. When you checked the runout of the rotor, it was within acceptable limits 2. After cleaning out the labyrinth 'rubs', you were able to restart the machine and it ran without excessive vibrations Can you please advise if the gas carries any particulates, and if so their size distribution and quantity (in ppm) ? What are the radial labyrinth clearances? Were all the 'rubs' in the same angular alignment 0-90 deg., with 0 being the 12 o'clock... [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
Old Grease
Registered Member By design, the best situation is to have a purge plug opposite the grease fitting (zirk). When regreasing at regular intervals, remove the purge plug and re-grease while the bearing is rotating. Continue greasing until fresh grease is seen emerging from the purge hole. Leave the purge plug out while running the bearing for 10 minutes or until the bearing reaches its normal speed and operating temperature. The bearing will purge any excess grease to prevent undue pressure on any sealing... [ more ]
Registered Member If the bearing housing is well designed, it must have a grease niple and an oulet, I think it is called a "down commer" (excuse me if I am wrong) so the old grease is displaced. [ more ]
Registered Member What we notice is the base oil becomes involved with various chemical reactions causing the NLGI rating to thicken until such a time where as the bearing is running on the thickener soap with very little base oil and failure will soon follow, relubing prevents this from occurring. [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
technology cleans internals without flushing
Registered Member Keara - You are most welcome on this board - but please refrain from selling - it tends to send the very people you wish to sell - away rather than toward your products. Please post something useful like helpful information about filtering and please state your affiliation if you are a vendor. Terrence O'Hanlon [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Monitoring roller bearings
Registered Member We haven't found a way of vibration monitoring the conveyor bearing either. Have been able to detect some problems by monitoring torque however, it is usually detected too late to be of any use. Best to examine operating and maintenance practices. We found most of our problems were caused by lack of lubriction. 1) To grease the conveyor bearings requires a shutdown and partial disassembly of machine. The routine to do this was often skipped due to the minor production impact. This routine is... [ more ]
Registered Member Miguel, I have run into the same problem with ours and not been successful due to the location of the conveyor bearing and the slow speed of the bearing. The bowl speed of our machines are roughly 4,000 rpm and the conveyor is somewhere around 40 rpm making it next to impossible. One thing I have noticed over the years though is when I start to see a high imbalance accompanied with an increase in looseness this usually means a conveyor bearing is on the way out. Not all the time but most. I... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Agitator gearbox vibration monitoring
Registered Member A few questions come to mind. Is the tank heated with steam? Anything else dumped to tank?Do the spikes happen to both machines at the same time and at what frequency are they happening? Low frequencies can appear as a "ski slope" at the low end of the spectrum. If the transducer is really sensitive my guess is its picking up any random event that happens such as a door slamming, etc. The mixing shaft speed (1x) may increase if tank contents are disturbed by steam injection or added flows,... [ more ]
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High Axial Vibration
Registered Member Hi all. If you have a segmented bull on the mill and you are taking a few averages, I would suspect it is misalignment between the pinion and the bull causing this. Maintenance personnel would routinely lead the mesh and realign, adjusting for wear. If they are allowing significant variation segment to segment on the bull (for example, checking only part of the total bull gear mesh with the pinion), you'll see misalignment no matter how well their "final" might be. This would explain some... [ more ]
Registered Member I suspect the second order of gearmesh indicates a misaligned pinion. [ more ]
Guest Alcoa Gary [ more ]
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Low pass and high pass filter
Registered Member Hi Miguel, You do not need to use high/low pass filtering in Vibscanner. The method to have an early warning is by using Schock Pulse measurements. Yet you will see defect frequencies in velocity spectrum when the defect is progressed enough to yield sufficient rms value so that it reaches to the minimum level of the instrument's dynamic range. Please consult you vendor for details. Regards Sina Kuseyri [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Best bearing type
Registered Member Good day John, The best, if you could send me the photo of the defect bearings and the conclusion you based on. If you base on the Self-aligning Brg at NDE of the fan, it may not a best call. As you know, rolling element – balls have lower contact point compare with rollers, and the reason force acting on the NDE would be radial, i.e unbalance,etc.. . This for the load carrying /distribution. Thrust/axial load always will be absorbed at DE should be more compare to the other end. Be sure... [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
Lacquer formation
Registered Member Hi Cid, Oil degradation in this form is usually related to an over exposure to heat. Check your oil analysis ICP results and if Si is elevated this could be why the lubricant is cracking and depositing around the engine as this could indicate fine hard contamination accessing the induction system and cracking the lubricant as the hard particle remove metal. there are lots of other reasons but you should pick those from the normal oil testing eg Coolant loss will cause the lubricant to break down [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Pump and Motor Looseness
Registered Member You might also want to review the condition of your coupling dependent of type of coupling installed. [ more ]
Registered Member Hello Christoffel: Rule of thumb, anytime you see multiple harmonics odd, even or both assume loosneness. Check your harmonics on the pump of RPM, check amplitude in the vertical direction as well. Usually in your description of harmonics across the coupling, could be a base or grouting problem. Key is if the vertical vibration exceeds the radial by more than 50%. Bill Prusak http://ewavetech.com Asheville, NC [ more ]
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Vibration Analysis, inspection intervals
Registered Member I do appriciate your feedback. Thank you [ more ]
Registered Member Mr. Jacques, RonFrend has given a comprehensive and useful guide. For emphasis (only), I want a add a comment about equipment criticality, since some others have brought up this subject. Criticality, pre se, has nothing to do with the inspection interval; the only parameter that matters is the rate of degradation from incipiency to functional failure. The rate of degradation doe not depend on criticality, it only depends on the nature of failure and the physicsl(or chemical, biological etc.)... [ more ]
Registered Member I have been in vibration monitoring at this mill for over 30 years and started before we had data collectors and computers. This is a question that our condition monitoring team struggles with. Our stated purpose as a condition monitoring team is to find problems or potiential problems early enough to plan, schedule and react to them to minimize any process downtime and maintenance costs. We view our the condition monitoring team as a screen made up of all the technologies (vibration,... [ more ]
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Tightening Anchor Bolts
Registered Member If you are looking for a published authority for the formula: Audel's Millwrights and Mechanics Guide, Fifth Edition, Page 667. They use the formula: R=TL/(L+C) or their published version: R=T X L / (L + C) T=Torque Required R=reading on scale L=Wrench Lever Length (center of pivot to end of handle as opposed to middle of handle as was suggested in the tip) C=Extension Length Alan challenged me to produce a formula to correct for the crowsfoot not being in the same plane as the torque wrench... [ more ]
Registered Member Hello Alan, Now I made a mistake. X = Torque reading T = Desired torque A = Length of wrench to center of handle B = Center of wrench to center of crowsfoot C = degrees offset (range is 0 to a max of 90˚ for this formula) D = Amount to add Y = Torque Reading to use X=TA/(A+B) D=(T-X)*C/90 (this was the error) Y=X+D Regards, Jon McFadden [ more ]
Registered Member Hello Alan, It's a linear solution, so all you have to do is figure the percentage of 90˚ that the crowsfoot is rotated from the plane of the handle and add that amount to X. X = Torque reading T = Desired torque A = Length of wrench to center of handle B = Center of wrench to center of crowsfoot C = degrees offset (range is 0 to a max of 90˚ for this formula) D = Amount to add Y = Torque Reading to use X=TA/(A+B) D=X+((T-X)*C/90) Y=X+D Measuring breakaway torque is a valid use of the torque... [ more ]
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Tranformer Explosion Tip
Registered Member From a devoted Maintenance-Tips reader: I know that you rely on your contributors for content and accuracy of their articles. I also don't want to be in the middle of a thermographer battle. However, the recent IR tip you sent out titled "Preventing a Transformer Fireworks Display" had some statements which can confuse your readers. While it is true that gases are produced when arcing takes place in an oil-filled transformer, it is not true that the risk to the transformer is the explosion... [ more ]
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Heat Exchanger Fouling Problems
Registered Member Hi Desmond, Fouling is only one of the reasons for loss of heat transfer. You may wish to examine the following possibilities as well. 1. Deposition of salts or other particulate matter on the hot surfaces, providing a thermal insulation layer. In this contect the analysis of the black particles you mention will be useful information. 2. Dissolved gases, e.g., caused by aeration of the coolant can cause heat transfer loss. These gases can come out of solution when heated and 'sit' on the... [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
Correct Amount of Lubrication
Registered Member Thanks - I Will do so Terry O [ more ]
Registered Member Terrence, please refer Mike to the post on 8'bearing lubrication dated 21 September 2004. The SKF formula for quantity of grease on initial lubrication and re-lubrication are there. However here is the formula (bearing O.D. X bearing width X .114) this will give you the quantity of grease in ounces on initial lubrication. Dependant upon the service of the motor, that will determine the quantity (25-30%)on re-lubrication and frequency. This information can be found on the SKF websight also. [ more ]
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Results to Condition Based Monitoring Survey
Registered Member Bryan The paper has been published on Plant Maintenance web site, hence you don't have to pay, other that in compliments to the author: Go to: http://www.plant-maintenance.com/m-news/edition49.shtml#ARTICLE4 [ more ]
Registered Member OK!I now realise that they wanted me to pay for it ) [ more ]
Registered Member Bryan I've just looked at the ASME web site. The paper is available from the following web address: http://store.asme.org/category.asp?catalog%5Fname=Conference+Papers&category%5Fname=Maintenance+Engineering%5FESDA2004&Page=1 This should answer your question. Regards Phil [ more ]
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Pump Cavitation and High Vane Pass
Registered Member Patrick, All pumps have some cavitation or vane pass vibration. The amount depends on where on the curve they are operating. If you want to know if you have too much you must first take pressure readings on the pump suction & discharge. This will help you tell if the pump is operating on the designed curve or not. If it is not, you must find out why it is not. If the pump vibration has increased from normal then something has changed. Locate the change and start there. If the pump is a... [ more ]
Guest We had a problem with cavitation reciently . We inspected the pump and found that the line from the discarge leading to the packing housing was disconnected. The discharge was used as cooling medium and to create a possitive presssure in the packing . Packing was fitted in the slot where the cooling water had to go in.This caused air to be sucked in through the packing causing the pump to cavitate.The process controller could actually control the cavitation be adjusting the... [ more ]
Guest We had a problem with cavitation reciently . We inspected the pump and found that the line from the discarge leading to the packing housing was disconnected. The discharge was used as cooling medium and to create a possitive presssure in the packing . Packing was fitted in the slot where the cooling water had to go in.This caused air to be sucked in through the packing causing the pump to cavitate.The process controller could actually control the cavitation be adjusting the... [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
8' Bearing Lubrication Procedure
Registered Member Hello, I just joined the sight and saw this post. In answer to your question of how much grease is required of an 8 ft. dia. bearing that is 4inches wide , use the SKF formula bearing O.D.(in inches) times the bearing width times .114 (O.D. X W X .114) this will give you the quantity of grease in ounces by wt. required for initial lubrication. based upon the speed quoted for this bearing I would think that re-lubrication should only require about 25% of that amount based upon SKF... [ more ]
Registered Member With this type of application is will be important to monitor the used grease to see what is occuring in the bearing. We don't think VA will offer good info @ this slow RPM. To start pre pack as per the bearing makers instructions, this should work well and we don't want to void any "warrentees". When the bearing is being installed it is very important to ensure there is a grease relief path so as the lubricant is applied there is an easy path for the used grease to escape and this path must... [ more ]
Registered Member This is a slow moving large diameter rolling ball bearing. What is unknown is the characteristics of the OD and ID mount. Each ball is rolling 3 times a second or traveling 3 feet per second. This seems to be a low rate and so not much heat is being built up in the races. Grease is a oil lubricant mixed with a soap to fix it in location. Thus putting grease above the seal ID line would result in seepage. How often due you grease the bearing? Do you use and ultrasonic grease gun to determine... [ more ]
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Wireless Condition Monitoring
Registered Member Rep warning!! Check out www.techkor.com for their wireless accl offering... [ more ]
Guest Dear Gordon We development and manufacture electronics devices for vibrations measurement and analisis. May be we can help you.Please, vivis our website www.semapi.com or www.suscorp.com Thank you. [ more ]
Guest Dear Gordon We development and manufacture electronics devices for vibrations measurement and analisis. May be we can help you.Please, vivis our website www.semapi.com or www.suscorp.com Thank you. [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Thermography to detect failure in double tanks of LNG - liquid natural gás
Registered Member I can't speak to your specific problem. BUT...I've used thermography on condensers to look for in-leakage around hatches. The condenser was at vacuum and hot so leaks showed up as cool spots. After shutdown and repair of seals and gaskets we did post maintenance thermography on restart to verify that the leaks were repaired. Hugh Hackett [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Fan balancing machine vendors
Guest Dear Dave We manufacture electronics devices for balancing, vibrations measurements and analisis. I can help you to find you need, but to very low cost. Thank you Aldo Gonzalez ahgonzalez@semapi.com.ar www.semapi.com www.suscorp.com [ more ]
Registered Member Thank you for the replies. [ more ]
Registered Member look at www.pruftechnik.com they do a very well priced balancing only version of the Vibscanner. We use this for our field balancing work and it is extremely simple to use even for novices. [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
High Mileage Vehicles
Registered Member I have used high quality synthetic oils with 20,000 mile drain intervals. The engine now has over 260,000 miles and only been opened once to replace head gaskets that were leaking oil on the block. [ more ]
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Bump test to determine the resonant frequencies of a motor
Registered Member RLE: Sorry about the lapse in time, to many routes and repairs to complete! Say you have a one times turning speed of 1000 CPM. Your bump test reveals a natural of 950 CPM. The 950 CPM is within 10% of your turning speed therefore the turning speed is your forcing frequency. For most rotating units 10% move of the natural is enough but I have had to go 20% at times. The thing is do you move the natural up with stiffness of down with mass. Additionally, you would want to review the imbalance... [ more ]
Registered Member We have performed numerous bump tests over the years. It is quite common to find different resonances at different locations and / or directions. There are a number of reasons for this, including: bearing and structural stiffnesses, variations in mass distribution and different transmission paths. Your bigger questions will be: how close are these resonances to the exciting frequencies of the machine, and what can we do to change the natural frequencies. Regards Paul [ more ]
Registered Member Roger, yes it is possible to have two or more natural frequencies show up when doing bump tests . remember when bump testing you are not only exciting the motor frequency but also motor mountning frequency as well. "normaly" the motor readings will be higher freq.in the vertical plane as "most mounts are stiffer in this direction. If i suspect resonance I take readings in several places on the motor and skid and use a strobe light fired from the data collector and look for "Phase changes in... [ more ]
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RE : Ultrasound Technoligy-Pros and cons
Registered Member Hadrian UE Systems out of New York is holding a Ultrasound World Top Gun Conference at the Hilton Clearwater Beach Resort in Clearwater, Florida, October 24 - 27, 2004. They will have all their models on display along with the software for trending. There is also 5 free short courses offered. You can find more information on it at their web site www.uesystems.com [ more ]
Registered Member Hi Hadrian, I can recommend Holdoyds, it is a very reliable monitoring technicue. I am not knowlidgeable about the others mentioned here. The reason for the erratic dB trending might be because of different speeds of the machines or a veriety of other reasons that generate different dB levels. [ more ]
Guest Micheal, I am considering setting up the program to enhance my Vibration programme and to confirm some of my diagnostics.I have the equipment on order and included is a training course. I am also considering to having the various unit foremen using it to trend the deteriation on bearings, specially on critical machinery so to have maximum life from the equipment. [ more ]
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Metallic and Non Metallic Bearing Cages
Registered Member Non metallic bearing cages are also prone to siezure more rapidly than metallic ones which tend to hold the whole mess together as failure progresses. One of the reasons that oil and gas people spec metallic cages is their increased resistance to siezing and heat generation which is not something you want around hydrocarbons. So its a safety issue as much as a CM issue. Also its much harder to detect cage wear using oil analysis. OEM's use plastic cages because they are cheap not because... [ more ]
Guest To add a bit more info to JB comments: It was presented several years ago at a conference, that vibration data was collected on a pump and before the data was downloaded, the pump failed due to a collapsed bearing cage. The vibration data was scrutinised and no evidence of a bearing defect could be found. This led many people to specify to only install metallic style cages in their equipment. There are a few specific, typically high speed applications, where the OEM will only fit... [ more ]
Guest To add a bit more info to JB comments: It was presented several years ago at a conference, that vibration data was collected on a pump and before the data was downloaded, the pump failed due to a collapsed bearing cage. The vibration data was scrutinised and no evidence of a bearing defect could be found. This led many people to specify to only install metallic style cages in their equipment. There are a few specific, typically high speed applications, where the OEM will only fit... [ more ]
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Bearing Cap Vibration vs.Prox Probe Vibration
Registered Member This might no apply to your unit but I collect data and have the same frequencies showing up on a turbine driven boiler feed pump in a power plant. The case vibration is high but the prox probes show the shaft deflection is within limits. The source of this vibration was found to be coming from the coupling guard which is rigidly mounted to both the turbine inboard bearing and the pump which is transfering the vibration. [ more ]
Guest Rafael, Were you able to inspect the turbine DE bearings? I would suspect these to be the possible loose items based on the information above. I would check for the shaft loose in the bearing and for the bearing loose in the housing. Were you able to perform any of the previous suggested checks? If yes what were those results? I will provide additional suggestions when you are able to provide more data/inspection results. Regards Tony s Disclaimer: These opinions are mine and not necessarly... [ more ]
Guest Rafael, Were you able to inspect the turbine DE bearings? I would suspect these to be the possible loose items based on the information above. I would check for the shaft loose in the bearing and for the bearing loose in the housing. Were you able to perform any of the previous suggested checks? If yes what were those results? I will provide additional suggestions when you are able to provide more data/inspection results. Regards Tony s Disclaimer: These opinions are mine and not necessarly... [ more ]
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Vibration Analysis Training in USA
Guest In reply to your third question. Technical Associates have provided a metric exam paper for european clients in the past. And have also carried out training in the UK. Something worth considering when you decide to go beyond level-2. CE [ more ]
Registered Member Yes,CSI is a good course, but they seem to veer toward their equipment, I would recommend a course that is not tied to any equipment as is CSI,ENTEK, etc. I've taken both VI and TA and found both to be very good. VI focuses more on theory(such as a college course) where TA focuses on practical aspects. I hear that VCI courses are specialized on bearings and gearboxes. Hope this helps. Rafael [ more ]
Registered Member Hi guys, Thanks for your response. I am currently using iLearnVibration for training & reference, so I'll skip Vib-Assist. I believe they are equivalent to each other. I agree that certification tied up with membership sucks. Still, if Vibration Institute is the only one that is approved by ASNT, I don't have much choice. A 5 day training course sounds good & CSI is definitely good. My only worry is whether the course is centred around the use of their instruments. Can you give me... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
thermal imaging
Guest As I always say.. The more data you have the clearer the picture! Ignore the cost for a moment and imagine your condition monitoring equipment as an extension of yourself. When you walk up to the side of a machine you look at it, listen to it, note any smell present and may touch it with your hand. The technology we use today is just an extension of these age-old methods. The difference being that instead of being "hot" we can now be accurate to decimal degree precision. Instead of saying... [ more ]
Registered Member Bren, Here are a couple words of caution regarding thermography: 1. Know what question you are looking to answer with that technology. - For instance, if you want to know the running condition of the DC motor you might look at it's current draw and measure vibration, you might measure output and ripple voltage on the Power Supplies (if they are DC) to ensure components aren't failing. The point is Thermography is just another tool in the diagnostic tool box, use it when other technologies... [ more ]
Registered Member Training is very important. I believe a good Thermograpy program is impossible to have unless you and your personal understand the effets of emmisivity, transmitance, and reflectivenss of the material that surrounds what you want to use your camera on. There are inherant pitfalls some being wind affect, distance, range, and the ability to determine the correct pallet to select for viewing. Just my opinion and I am not and expert but have used it to survey equipment. [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Acceptable Vibration Levels for Pellet Dryers LDPE Plant
Guest Dian, as with all vibration sampling you have considered the transmission path. The further from the bearing you get the lower the detected figure will be fhen the bearings give-up. You have an ideal situation here to identify "brand new" healthy condition. Assuming that you have eliiminated all post-maintenance faults, you now have a benchmark to work from and possibly the normal operating condition from the historical data. If this is fact then you would be better looking at the... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
g's Spike Energy set-up
Registered Member Michael, on some of ours we have a fixed mount transducer between two spindles, that still is just an early warning and thats about all, if you want to pick out the particualar spindle you'll need a mag mounted set-up. [ more ]
Registered Member Yes they are gear driven. My biggest problem is time. At the present we only have about 15-20 hours per week to do collection (idle).I am trying to see what other individuals are doing. One of the spindles has 4 heads with up to 32 spindles each. With this time restraint i do not have time to do a formal anaylisis. [ more ]
Registered Member Michael, are you talking about gear drive gearboxes ? if so I am currently checking and verifying my own set-up's but maybe I can help. On 5500 rpm gear driven spindles Im a using 120K fmax and a 5kgSE filter to gather gSE Pk-Pk, I may have to go up to 300k yet but for the next two or three months Im just going to watch. I hope this helps and Thanks, Brad email brad.noel@gm.com in Sunny Spring Hill Tennessee [ more ]
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Bearing Fault Analysis
Registered Member JB, You have a chain of question. Beside the magnetization problem, the rest is best to apply bearing track marking analysis, which can give more specific toward problem. [ more ]
Guest Dear Dataware, Part of our testing is to run white metal bearing motors solo before installation and most of them would hunt magnetic centre.I have discussed it with our fitters and all of them said when they align they find the centres by bump test before aligning.Onsite we found that the ones that have hunting problems tend to have a beat frequency or a pulsating 1X RPM in tha axial direction. I have not checked this for ball bearing motors and find the question interesting as I have come... [ more ]
Guest Dear Dataware, Part of our testing is to run white metal bearing motors solo before installation and most of them would hunt magnetic centre.I have discussed it with our fitters and all of them said when they align they find the centres by bump test before aligning.Onsite we found that the ones that have hunting problems tend to have a beat frequency or a pulsating 1X RPM in tha axial direction. I have not checked this for ball bearing motors and find the question interesting as I have come... [ more ]
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Vibration Measurement Sensor in Spike Energy
Registered Member If you are talking about IRD (Entek/ird) spike energy, then you may use the sensor with 18khz natural freq. The thing to remember is wherever you use that sensor to collect gSe, you must continue to use it there. Your overall reading will vary depending on the resonance freq of the transducer. However, the spectrum will be the same. If you use the same transducer, then you can trend the overall just like you would any other reading. [ more ]
Guest Are you talking about SPM's Measure of Spike Energy? If Yes, then yes you do have to have a special transducer. If not then I don't know [ more ]
Guest Are you talking about SPM's Measure of Spike Energy? If Yes, then yes you do have to have a special transducer. If not then I don't know [ more ]
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Michel tilted pad bearings
Registered Member Hi Tony, I'll try checking for that off-line, but I'm not too sure. The 0.924X peak has sidebands, not 1X. Also, I took current signature analysis data on the motors, which is much more reliable for broken bars. There were no strong PPF peaks around the line frequency. If I get something concrete, I'll post it here. Best regards, Aditya [ more ]
Guest Aditya, I looked at the spectra provided and suggest that the sideband spacing may be related to Pole pass freq around the running speed harmonics. Further investigation of rotor faults may be useful. Hope this Helps. Tony S. Disclaimer: These opinions are my own and not necessarily those of my employer. [ more ]
Guest Aditya, I looked at the spectra provided and suggest that the sideband spacing may be related to Pole pass freq around the running speed harmonics. Further investigation of rotor faults may be useful. Hope this Helps. Tony S. Disclaimer: These opinions are my own and not necessarily those of my employer. [ more ]
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Bearing stress fractures
Registered Member Thanks Graham, I have noticed also that there are striations on the outer races of the coupling bearings, as though there were no retaining pins. If I look at it in the limiting sense, say a bearing WAY too small for the application, then of course the first things to go would be the rollers. Perhaps the bearings might be too small for this application. I am told there was never any problem until just recently however. I will check the runout of the shafts and see if there is some problem... [ more ]
Registered Member Most of the cracked races I have ever seen have been related to overload or shafts and housings being out of round Graham [ more ]
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Asset Condition ManagementPosts About Lubrication and Oil Analysis
Zinc free Hyrdraulic Oil
Registered Member dear ledforph let me know what,s the color of jelly substance and what is the oem recomendation for lubricant and what is the operating temp. [ more ]
Registered Member Hi Ledforph We have used a similiar zinc free hydraulic oil with ashless additves in screw compressors and faced similiar problems .We had taken a lot of samples and on analysis we found that the organic and inorganic acidity were present in most cases . This is due to the additves that are being used (phosphate esters) which normaly gets converted to phosphoric acid which reacts with the oil and causes jell like formation. Please check with your oil supplier for the same. [ more ]
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Asset Condition ManagementPosts About Ultrasound Testing
Condenser Tube Leak
Registered Member What type of fluid in the condenser? Eddy current works well for tube imperfections. If its a refrigerant condenser, a trace amount of refrigerant and nitrogen is the accepted practice. [ more ]
Guest Rafael, I suggest you contact a local supplier of Ultrasonic equipment or services. This typically works well offline and is quicker than boreoscope inspection. Hopes this helps, Tony Sovar. Disclaimer: These opinions are my own and not necessarily those of my employer. [ more ]
Guest Rafael, I suggest you contact a local supplier of Ultrasonic equipment or services. This typically works well offline and is quicker than boreoscope inspection. Hopes this helps, Tony Sovar. Disclaimer: These opinions are my own and not necessarily those of my employer. [ more ]
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How to monitor winders.
Guest Randle, It sounds like you have many problems with the new machinery, a few suggestions. 1. Get the supplier/manufacturer involved to assist with these faults as they should have the most knowledge of the new model. 2. To assist with monitoring of the unit try thermal imaging as well as vibration anlaysis. Install accelerometer in locations which are difficult to access. Thermal imaging may be performed at the end of a production run if access is limited during production. 3. Test your... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
Product Contamination
Guest Patrick, The Root Cause of your failure will be typically within the evidence of the failure. Was there any syrup residue around the motor? Could a syrup leak got to the motor? Are syrup leaks common? What type of seals were on the motor? What condition were they in prior to the failure? What is your greasing program of the motors like? etc. I have noted product entering bearings previously which led to bearing failures, but from the evidence you presented this is only one of many possible... [ more ]
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Asset Condition ManagementPosts About Asset Condition Management
High axial vibration
Registered Member The lack of radial vibration and the sleeve bearing arrangement would indicate the coupling is trying to pull the rotor away from its magnetic centre. Check the magnetic centre and coupling gap/assembly is correct to negate this as the cause of the high axial vibration. To check for soft foot(which is what you are indicating in Q2) do a running check with the motor running by sequentially loosening and retightening each individual hold down bolt in sequence while monitoring live vibration... [ more ]
Registered Member First we need to know the spectra content generating the vibration. What is 1X amplitude. What are the other peak frequencies. Second, a new or reconditioned motor should run 0.05 ips peak setting rubber pads or properly shimmed and bolted down. 0.16 ips axial is very high for a shop test. How was the shop test conducted? Adjusting the shims indicates soft foot which can create or agrivate internal bearing to bearing alignment. Regarding the beat, if you zoom in with high resolution you... [ more ]
Registered Member We use PdMA Motor Tester MCEmax for testing our motors. As you are sure the alignment has been corectly done, you need to check if there is rotor or stator problem. We do Rotor Influnce Check (RIC) using MCEmax to isloate problems to either rotor or sator. As the motor is turned incrementally by hand, a plot of its influence on the ststor coils is developed using inductance measurements. If the influnce on the pole groups is uniform, the effects are caused by the rotor. If the influnce on... [ more ]
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