Hi there,

I'm new to this forum. Our company designs and assembles large gearboxes, mostly for the oil and gas industry. We would like to buy a vibration data collector/analyzer to take some baseline signatures of our new boxes before they leave our site. As well, we would use the analyzer to measure data of noisy boxes on site and possibly out in the field to help with diagnostics. In summary, I guess you could say we are thinking of using the equipment as part of our Quality Assurance program.

A typical application runs at around 1000 - 1800 rpm. The maximum gear mesh frequency would be only at around 2.5 kHz.

We believe that we really only need a BASIC machine. However, we also want something that is USEFUL for analysis. I believe the 3 main capabilities the collector/analyzer should possess would be:
(1) Time Waveform
(2)FFT
(3) Demodulcation

Does anyone have any comments on whether these 3 capabilities are a MUST - ie should be our priority when looking for equipment? Can anyone suggest any particular equipment? I have researched into CSI, SKF, Commtest... the usual suspects. But since I am unsure what even the most BASIC capabilities are, I am finding it difficult to weed out the best euiqpment for us. Has anyone ever had any experience with Vibratel's (International Measurement Solutions)Mini Monitor and AD-LIB software? [I am interested in this company's abilities for longer signal (time waveform) recording for post-analysis with other software).

D.Denny

There have been several posts on this topic. You may want to do a search for some of them.

Oh, I'm sorry. I have spent TONS of time on this forum reading through just about everything in the Vibration Section. I really thought there was nothing on this topic so far. I just did a search on "equipment" and didn't come up with any info to answer my question. I will try other searches.

I was hoping someone could give some tips into the 3 main capabilities they would look for in an analyzer (to be used with gearboxes).

Regards,

D. Denny

Denny,
I have only used CSI brand equipment and am not really qualified to answer your question about other brands, but I will say that from what I have read and heard from other people, all of the brands you mentioned will handle what you want. I believe that your biggest obstacle will be becoming proficient with whatever brand you choose. You may consider choosing several brands and letting the sales vendor come and demonstrate. If they won't come before they have your money, I wouldn't expect much support after they have your money. You may also consider asking for private answers via e-mail. Most people are sensitive to avoid "brand wars."

I found some useful info in the gear book at this site: http://www.vibcons.com/vibration_analysis_books.shtml.

David Eason

You might look into what your customers are using. Showing up with the same equipment that your customers use will build a sense of credibility with them. Going cheap will not help your credibility.

Having said that, you can hardly go wrong with the usual suspects.

Denny,
I've used CSI equipment for @ 8 yrs now. Can't speak about the others but, the ones you mentioned, from what I've heard and read, are also good candidates. The only reason that I mentioned above to do a search is like David said, alot of people on this board try to avoid the ""brand wars". If you'd like my personal opinion on my equipment and soft ware feel free to e-mail me
roy dot gariepy at dorlastan dot com
kind regards,

I've always used CSI equipment and love it and would hate to change--I'm too far along the learning curve now. But it sounds like you're a smaller company with a smaller budget. If I were in [what I perceive to be] your situation, I would stick with the smaller companies you mentioned plus Ludeca's VibScanner, National Reliability Systems has a small handheld, I forget who makes the V-Series line, plus a few more. Check the trade magazines. Seems like the smaller companies include more for the money--dual channel, balancing included, long waveform captures, etc. And that's just in the portable line of equipment. If you just need something in the shop, you could probably build your own system to acquire the data, and, like you said, use different software for the signal processing.

quote:

Going cheap will not help your credibility.

I agree with Steve's comment above. I am always amazed at how little most rotating equipment manufacturers know about vibration analysis. I tend to recommend equipment based on their "apparent" knowledge. For instance, Chicago Blower gets my fan recommendations because they put a lot of thought and material into their bases, and they at least put a sticker on each fan showing the test-stand vibration readings (though they neglect to use a permanent marker, and don't specifiy the vibration units or measurement conditions).

You sound like someone who will have little trouble becoming proficient in the basics of vibration. As Steve said, don't do this "on the cheap"... spend a little extra money, get a good system and the training to go with it. Then impress the heck out of your customers... you will get all their repeat business as well as referals.

Bless you! I appreciate that a company would do such a thing. Most any analyzer would suffice. IRD, CSI, DLI, or most of the newer companies equipment.

If you tied it in with software, and baselined each gearbox, that certainly would be a selling point to me, if the following were known:

-what kind of load did you have it under?
-where did you take the measurements?
-how was the gearbox supported during the time of the test?
-was your calibration known and acceptable?
-were your measurement parameters specified, ie, mils (peak to peak), g's (peak, or RMS), etc.
-would you share this info with your customers?

If you could answer these questions for the customers who perform such tests on their plant's equipment, I think you would hit a home run!

Thanks to everyone for responding with such great information! Very helpful. We are not trying to go cheap here, but, as probably most of you know, vendors will always try to sell you MORE...with all the bells and whistles. I have to give a presentation to the managers/owners on this with a list of features/drawbacks to each equipment. That is tough to do until you start using the equipment. And we are not going into the business of condition monitoring, so we won't be going to our customer's sites all that often...only to service our own boxes. This really will be used as part of our Quality Assurance program.

Thanks again for all your input. I am going to act on many of your suggestions.

D.Denny

Remember when doing this that like Stan said load is critical. So critical that if I were buying one I really wouldn't put a whole lot of value to the readings unless they were done under significant load which will be tough since you make large gearboxes.

I appreciate that there are manufacturers out there who are concientious enough to consider doing this, but I cover some very large gearboxes and when they are running under light or no load they are always nice and quiet but when you speed them up and increase the load, the gearmesh frequencies really jump up.

One thing that would be of help to vibration analysts would be if you performed bump tests on the gear and shaft assemblies and published the data.

Good Luck,

You would be high on my list if you furnished a tag with at least the tooth counts for each gear. I don't think this would be a disclosure of proprietary information and it would really impress any vibration analyst that walked up to your gearbox.

Vendor Warning

Hi Denny

Along with all the other systems that have been listed, you might want to take a look at the MAINTelligence system - our system has interfaces to several vibration data collectors, with all the usual bells and whistles you would expect on the software side.

We also have interfaces to all the western Canadian oil analysis labs for lube oil analysis results - which I think you would be interested in if you are carrying out gearbox analysis.

You might want to attend the local CMVA (Canadian Machine Vibration Association) chapter meeting this Friday (May 6th, 2005) - its at the Richmond Hotel and Convention Centre, 7551 Westminister Hwy, Richmond, BC, V6X 1A3 604-233-3952. For more info, contact
Stephen Richard, BC Chapter President
Ph (250) 640-4256
Fax (250) 561-3985
Stephen_dot_Richard_at_Canfor_dot_com

Regards

Steve Reilly
Design Maintenance Systems
North Vancouver, BC
www.desmaint.com

Hello D., since Steve opened the advertising box, :-) I will add that you can come a long way using a used collector and software. The investment will be a fraction and the report will not reveal the age of the equipment used. You can surf often on e-bay or you can buy from me. I collect used stuff and sell at real cost. Best regards Arne

Denny,
Any day may be will can help you :
www.vibinst.org and www.bentlynevada.com

Denny,

A few weeks ago I was at your same position, needed to buy an instrument to see what happens with some machines. Analize a lot of alternatives and decided to buy ME42 from VIBRATIONSTEKNIK AB. Price and specifications seems to be very good for this kind of services.

I've used CSI 2115, 2120; SKF CMVA60 and CMXA50, Vibrotip, MicroVibe, and others. ME42 is a very solid option and price is very very good.

Regards

Iván Pérez G.


Sponsored by RELIABILITY Magazine & Reliabilityweb.com Join or Manage Your Profile Posting Boards Machinery Condition Monitoring and Predictive Maintenance Posts About vibration/alignment/balance Equipment selection[/quote]

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Vendor Warning

D. Denny, a laptop type system sounds like it would work well for you since you don't plan on going in the field to the customer sites. If you are interested in options other then CSI and SKF, feel free to drop me an email.

To answer your questions, I consider TWF, FFT and demodulation a must. The demodulation will allow you to detect problems before they appear in the raw spectrums and can be an asset in correcting problems before the gearboxes are shipped.

Since this equipment will be used on a test stand, getting something that can continuously monitor the equipment while varying loads would be a big hlep also.

Mike Bensema
FAG Industrial Services
www.fisna.com

D.Denny,

You probably have customers that have several different brands of data collector systems, so trying to get one that is used by a specific customer may not have the desired impact with other customers. I would say that the parameters you described are all usefull tools for the analyst. As described by others, test stand test results cannot reveal all possible defects, due to lack of load, but many manufacturers have been very succesful with using test stand vibration measurements to discover problems before a machine leaves the manufacturing plant causes a problem both for them (warranty issues) and their customer. The gathered information from testing units before they get shipped out will also give you a better understanding of all normal vibration issues that your customers face in the field, and a better footing from which to speak with some intelligence when faced with the inevitable finger pointing (gearbox?/motor?/driven unit?) questions that will arise as to the source of a problem in a field installation.

You may want ot consider a system that is designed for the specific purpose of test stand vibration measurement, yet retains portabilty. As a manufacturer performing test stand vibration checks, your needs differ quite a bit from someone doing condition monitoring routes on rotating machinery in a plant. The signal processing technology is the same and the interpretation of the vibration data the same, but hadling of the data and documentation of the testing done, archiving the data, etc. is quite different. Getting a system with these data handling capabilities, that can be used on a routine basis by someone who is properly trained to acquire the test data, but not a vibration analysis expert, is perhaps more important for your application. Also, for test stand applications speed of data acquisition is often important, so a multichannel simultaneous data acquisition makes a lot of sense for these applications. Place the required transducers, scan a barcode to record model number and serial number info and customer info (in case the customer has any specific test configuration requirements) the system will automatically configure the proper measurements for the gearbox to be tested. The operator pushes the start button for the test stand and when the prescribed test conditions are met the data is acquired and a report printed and stored electronically with the test results and Pass/Fail identified. If a FAIL is flagged, the most probable sources for the defect are listed on the printout.

If there is a failure of one of the tested units in the field later on at a customer location the test data can easily be accessed in the database by customer order number, serial number, model number searches, etc. Meanwhile engineers on your company network can view trends of data and statistical analysis of all similar gearboxes tested with the test stand system. Another advantage of the multichannel test stand system is that it can record other non-vibration data of interest at the same time as it is acquiring the vibration data.

MAARS, Inc. from Knoxville, TN makes a system designed for test stand applications that can be integrated with their portable multichannel analyzer, if ever you need to do vibration analysis away from your manufacturing plant. It has all the feature described above. The local rep for you is Spectrum Instruments, Ltd.

http://www.spectrum-instruments.com/company/

Skip Hartman

Denny, my background includes doing vibration and acoustics work (18 years) on large geardrives for a major manufacturer formerly located in King of Prussia PA.

Gear drives come in all shapes and sizes so one consideration will be the type of transducer you employ for your test work. If you are building drives with primarily fluid film bearings then casing transducers won't permit good qualitative analysis at light and low loads. You will need non-contacting proximity probes. If your drives are rolling element bearings then casing transducers may prove adequate.

Another consideration is the need with your product to do an adequate API 613 test. If you feel that is necessary to do API 613 testing (or will be in the short term) you should bite the bullet and get multi channel capability up front. Otherwise you will be tied to using consultants to do his type of documentation at a cost of about $3000 to $5000 per test.