Does anybody have data for Flender 4-stage gearbox B4SV 18? I need it for a job next tuesday and all I have is a drawing and partlist without any clues for internal ratios/rpm.

Thanks in advance

Arild

AO3100_Flendergir_B4SV_18.pdf (1,092 Kb, 56 downloads)

It may be possible to get some info from the spare part plant in Herne infos@flender-service.com
they have a 24 hour service +49 17228 10 100 have not tried it so I don´t know what info they can or will provide. Since the local contacts was gobbled by Siemens I don´t know what they can find, they refer to adinfo@siemens.no. Olov

In cases like this I print drawing on a good printer - copy / enlarged. Measure the diameters of the gears, and using the overall ratio 126.51 calculate the bevel ratio. This gives r1=1.84, R2=3.929, R3=3.815, R4=4.586. This is enough info (in CSI)to setup the machine. If set up as "variable speed/constant load" you can enter the strobed input speed and you should be close enough. Also enter the bearing numbers which are on the parts list. From the data (rotational sidebands around gearmesh)you can then correct speed and refine set up (since measuring manually will have more inaccuracy than I would want to see). The answer might also be on the parts list - the numbers after the gear description but I have never figured that out properly. Anyone??? Best regards,

This message has been edited. Last edited by: Vibe-Rater,

Measuring the diameters on the drawing is one way to go, gives an estimate on the shaft speeds close enough to set up points (I use SKF Prism4). I have tried to use the numbers after the gear desciption (the last number is the bevel ratio?). Multiplication of the numbers gives a result close to the total ratio 126,51. Maybe this is the answer?
I have also sent a mail to infos@flender-service.com requesting information, but no answer yet.
Just have to use what I have here I think. Thanks for your inputs.

Arild

Ratios_B4SV_18.pdf (97 Kb, 27 downloads)

Have you any vibration data on the gearbox? Have you or can you strobe/tach the input and output shaft? Does the data, if you have any, show any thng that appears to be gearmesh(s) sidebanded by something. If there are gearmesh frequencies present and one knows the input and output speed, sometimes it is possible to get fairly close to the ratios and number of teeth on the gears. With a little luck, these numbers can be calculated right on.

But with you having to know this information by Tuesday, my guess is you have no vibration data, huh?

OMOAICBTW

quote:

......But with you having to know this information by Tuesday, my guess is you have no vibration data, huh?

You are right, no measurements have been done on this gearbox. Still no answer from Flender so I will use the values I have found and set up the measurement points.

Thanks everybody

Arild

The idea of scaling from a print and getting diameters and then working back to a tooth combination can often lead you astray. The cutaway drawings for drives of this nature very often are only "representative" no scale intended. Thus working to a calculated diameter may not work well.

By far the hest way is to get the actual tooth combination. I have also found over the years, unless you have plant contacts, deal with your local sales person. Sending an email to customer service will rarely work.

John from PA

Suppose one were to precisely measure the input-output ratio. The example below shows that one could make a significant error in the ratio if not very precise (I set up a 37/118 example.).

x
x =

0.3135593

-->[n,d]=rat(x,.0001)
d =

118.
n =

37.

-->[n,d]=rat(x,.001)
d =

51.
n =

16.

In the above the function rat produces a rational approximation to the desired accuracy. One answer is correct and the other is not. Add errors to the measured ratio and the results can vary more. You should get the numbers.

You will probably be able to get the high speed gmf right away from the vibration data. Any sidebands will give you another probable shaft speed. The nameplate will give you the exact ratio, so you can get another shaft speed there.

I made a simple spread sheet to calculate all the shaft speeds and gearmesh frequencies that helps me when I have to derive information like this.

Like Bill said, though, get the tooth counts if possible and if you can't, do not considered derived information to be anything more than a good estimate. You can miss a huge defect if you assume that a pinion is 33 teeth instead of 32.

And definitely, do not forget the waveforms. Big defects like broken or cracked teeth may not show up in the spectrum.

Unfortunately no work done today. The plant was shut down due to a small fire (No, not because of the gearbox....)

I agree in what you say about derived information , but what about the numbers in the part list; can they describe the ratios between pinion and wheel? If multiplying the numbers for all the gearpairs the result is close to the overall ratio.
And: I never forget waveforms when analyzing gearboxes

Of course the exact numbers would be the best but ArildF does not have them and would like other suggestions before Tuesday. I guess it wasn't necessary as it is now Friday. I think this is about figuring out the answer without those details being available.

I agree with John from PA that your local Flender rep is the best chance, he/she will have more clout with Flender head office. (and might even get a sale out of it one day)

Drawings from the major gearbox manufacturers these days are all pdf’s from autocad or the like (or scans from hand drawn and it is rare that draughties don’t draw to scale or at the very least write “not to scale” on the drawing.)

I have never had problems coming very very close using this approach in conjunction with high res data, post fine tuning and care and attention. It should of course be kept in mind that there will be an error and missing by one tooth will change the ratio calcs more than the 2 decimal places in the quoted overall. Always perform the overall calcs using the teeth numbers that you think and if it does not come out to match the ratio then you are probably wrong.

And like ArildF I would love to know what those numbers on the parts list mean and more importantly how they relate to the the ratios within. Rgds.

Problem currently until dust settles is that Flender now is squeezed into Siemens and it is hard to find people. I have a friend that used to work with Flender Service so I asked him for the data using his direct contacts but still this way also take time, maybe week(s) but it normally eventually pop up. Olov

Yes Oli,

In searching for my old contact I found out Flender was gobbled by Siemens. Lo and behold same name pops up under Siemens and I have requested the info - see how that goes. As well as hopefully helping AridF it might rekindle my old contact. Will let forum know if anything useful bounces back. In any case if anyone finds out, can they please post ratios to check accuracy of my suggestion earlier. Am hoping to be within 5% on measured diameters alone. Rgds.

This message has been edited. Last edited by: Vibe-Rater,

OLI and Vibe-Rater: Thanks for your help

The job is postponed until monday. If I see something in the spectrums I will post it.

Have a nice week-end

Arild

These are what are termed "catalog" gears most likely, in that you can go to a catalog and using desired transmitted horsepower and overall ratio pick from a list that will do the job. As such, at least here in the States it should be kept in mind that a gear box nameplate ratio can vary by as much as ±5% (depending on drive type) so determination of the exact ratio can only be accomplished by checking actual drawings. Some background information...in 1959, AGMA published information sheet #271.02, "Ratios for Helical and Herringbone Gear Speed Reducers" which listed "standard" ratios based on a (1.5)^0.5 progression. It included a table of "Gear Ratio Tolerances": ± 3, 4, 4 and 4% for single reduction, double, triple and quadruple reduction, respectively. AGMA 420.04 (enclosed drive standard) in 1975 repeated the ratios, but modified the tolerances to 3, 4, 4, and 5%. Current enclosed drive standards (e.g., AGMA 6010 or 6009) have a clause on preferred ratios, but any mention of tolerances has been deleted. The standards only say that ratio is to be indicated on the nameplate, but does not stipulate nominal or exact. Checking Falk, Flender and Hansen websites it is interesting to see what they do in their catalogs. Falk's standard products state the 3-4-4-5% tolerances apply. The other manufacturers indicate they give exact ratios, but only to three or four significant figures. Note, most of this doesn't apply to gearing manufactured to API 613, where the ratio to four significant digits is on the nameplete.

In summary, you even have to use care when you know the nameplate ratio. If doing critical work check with the manufacturer and get the exact ratio. If the machine is shut down you usually can gain access to an inspection port and count out some if not all of the members. Hmmm...if you have a gearbox problem perhaps you should be looking inside anyway, even if only through an inspection port.

Also, on that design, a common mode of failure is the lower bearings on the helical shafts failing. Debris and water tend to collect at the lower end of the shafts causing shortened life.

John from PA

I have the lucky numbers:

Part no Teeth no
100 19
102 34
300 19
302 86
400 21
402 82
500 19
502 76

Did I win? Did you win? What was the prize a Beer? Or a bear? It´s Friday and the kitchen floor is half done! Olov

I think that half done deserves a beer!

What is it, about 4 o'clock for you? It's 5 o'clock just to the east!

Attached are your gear associated frequencies based on OLI tooth combinations and an inout speed of 3000 RPM. Something to note that the final helical reduction has 19 assembly phases so important to match mark the teeth on disassembly so that the go back together with the same teeth indexed. Due to the low frequencies generated in this set it would more likely cause a situation of increased wear than the audible noise commonly encountered.

John from PA

gear_freq.pdf (31 Kb, 15 downloads)

Yep half was around 4, I got some further, got the fridge back now and I will have a beer and leave the rest until tomorrow. Olov

Only half done? You'd better have a couple, your wife is going to be mad.