Conundrum for the collective!

[Paul KempParticipant @paulkemp46892]

This question has no relation to model engineering but I am sure someone on here will know the answer!

I am trying to confirm that the output flange from a Danish produced gearbox conforms to a standard! It has an OD of 225mm and thickness of 25mm, a male spigot of 145mm diameter 5mm high and 12 bolt holes 22.5mm dia on a 190mm PCD.

One commercial source suggests this is a DIN 225 flange but another says it is non standard. Google is no help whatsoever in either delivering a clear set of dimensions for DIN standard power transmission flanges only directing me to manufacturers of shafts where this size does not seem to appear or pipe flange standards which also appear not to conform.

So can anyone tell me what standard this flange may be? Apart from telling me to contact the manufacturer of the gearbox who insist on just sending me a drawing of the flange but failing to comment on any standard! Which leads me to believe it isn't standard and source B is correct although as the gearbox has classification approvals surprises me somewhat.

Thanks,

Paul.

[Paul KempParticipant @paulkemp46892]

[David JuppParticipant @davidjupp51506]

What is the gearbox for? A lot of standard are industry specific. For example DIN(also BS) EN ISO 9409 is from the Robotics/Automation industry – but it doesn't match your dimensions.

Much easier to search for standards if you have some idea of the title, or at least a few words.

[Michael GilliganParticipant @michaelgilligan61133]

The fact that DIN 225 seems to be about fasteners may be relevant to your difficulty: **LINK**

https://www.din.de/en/getting-involved/standards-committees/fmv/wdc-beuth:din21:129254710

You may need another number

MichaelG.

[Paul KempParticipant @paulkemp46892]

Posted by David Jupp on 20/03/2019 14:06:47:

What is the gearbox for? A lot of standard are industry specific. For example DIN(also BS) EN ISO 9409 is from the Robotics/Automation industry – but it doesn't match your dimensions.

Much easier to search for standards if you have some idea of the title, or at least a few words.

It's a marine gearbox transmitting 900HP. I am pretty sure it's not SAE, that is the usual standard for bell housings and flywheels in this application and unlikely to be BS.

Paul.

[Paul KempParticipant @paulkemp46892]

Posted by Michael Gilligan on 20/03/2019 14:09:32:

The fact that DIN 225 seems to be about fasteners may be relevant to your difficulty: **LINK**

https://www.din.de/en/getting-involved/standards-committees/fmv/wdc-beuth:din21:129254710

You may need another number

MichaelG.

Thanks Michael. I have located DIN standard flanges including a 225 (which apparently relates to the diameter of the flange and not the actual DIN std No) that has a matching spigot diameter but only has 8 off 16mm bolt holes. I can't find anything that explains the mechanism for determining flange size, spigot and bolt holes etc for power transmission flanges or a table giving standard dimensions for the relevant options.

Paul.

[Michael GilliganParticipant @michaelgilligan61133]

To add to [or perhaps reinforce] your confusion, Paul, try this: **LINK**

https://mdmetric.com/tech/flangedim.htm

225 is conspicuous by its absence

MichaelG.

[JasonBModerator @jasonb]

That last link is for pipe flanges, I doubt they would use the same for power and they don't have a smaller spigot or recess for same..

Edited By JasonB on 20/03/2019 15:07:46

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 20/03/2019 15:07:03:

That last link is for pipe flanges, I doubt they would use the same for power and they don't have a smaller spigot or recess for same..

.

Thanks, Jason … Yes, I did spot that

As they say in the detective stories: I just wanted to "eliminate from our enquiries".

MichaelG.

[Mike PooleParticipant @mikepoole82104]

Searching for coupling flange May be helpful.

Mike

[Paul KempParticipant @paulkemp46892]

Posted by Michael Gilligan on 20/03/2019 15:01:28:

To add to [or perhaps reinforce] your confusion, Paul, try this: **LINK**

https://mdmetric.com/tech/flangedim.htm

225 is conspicuous by its absence

MichaelG.

Thanks Michael, yes I had seen that and interestingly the DIN 200 does have 12 X 22mm bolts. As Jason says though, no register / spigot for alignment. I am just amazed that a search for something you would think would be so common yields such a load of dross that is nowhere near what you want!

Paul.

[Paul KempParticipant @paulkemp46892]

Posted by Mike Poole on 20/03/2019 17:47:18:

Searching for coupling flange May be helpful.

Mike

Mike, did that too, found loads of stuff and nice pictures and companies touting to make them but no standard! I have in the past found SAE standard flanges with tabulated dimensions against the various SAE numbers but I can't find anything for DIN on shaft couplings – plenty on pipes though! I never did rate the Germans!

Paul.

[SamsarandaParticipant @samsaranda]

Try the website of Drivelines.co.uk.

Dave W

[Paul KempParticipant @paulkemp46892]

Posted by Samsaranda on 20/03/2019 18:26:24:

Try the website of Drivelines.co.uk.

Dave W

Dave, OK, did that but didn't find any specific reference to DIN standards? Do you have a direct link to a page that answers the question? I had a good dig round, they certainly have a lot of info on there, even downloaded their coupling catalogue but it's all for servo motors and torque limiters. I just need to know a DIN 225 coupling will fit the output flange we have! Can't believe this has turned out to be so difficult! Going to have to phone a friend I think!

Paul.

[David JuppParticipant @davidjupp51506]

Is DIN 225 coupling even a real thing? Could it be DN (Nominal Diameter) ? That designation is widely used in piping (which as we've seen uses flanges).

These days most standards are harmonised across Europe – so what is BS EN ISO xxxx in UK is DIN EN ISO xxxx in Germany. Relatively few purely National standards are left – though there are some.

I did a quick search on the BSOL site under Marine Drive – 50 pages of results…. , tried Marine Flange – just piping. Any more suggestions for what they might be called ? Is this main propulsion, or something else?

Can you tell us the manufacturer, or are you trying to make the quiz especially difficult?

Marine stuff could even have a specific Lloyds Register classification…

[RRMBKParticipant @rrmbk]

Hi Paul.

Age may be a relevant factor. Some marine engine builders will have machined the couplings in their own build yards, and bored them to suit the shafts. the hole spacing is then determined by the shaft diameter, being positioned midway between the bore and the OD. That's certainly how we did it when re – engineing some work boats of similar horsepower. Particularly awkward to use a Din or BS standard on a shaft built before they were introduced !

[SamsarandaParticipant @samsaranda]

Hi Paul, sorry but don’t have any link that I can give you, good luck hope you find the info you are looking for, it must be out there somewhere, not immediately obvious where though.

Dave W

[Paul KempParticipant @paulkemp46892]

Ok, age not an issue it is brand new not yet delivered from the factory. Manufacturer really not that important or relevant to the original question I think, I just want to find out if the flange of the sizes mentioned matches any established standard. Yes I am well aware of Classification Societies, their rules and approvals process, it won't be of any particular concern to them that the flange may be an odd ball as long as it can be shown by calculation and testing it meets their requirements. Unit in this case can be DNV approved for appropriate fee.

Had another dig around on the DIn website (Michael G provided a link also) and searching "marine shafts" gives a fair number of links, most interestingly enough seem to be referenced back to SAE standards. I found one I think may be relavent but they want to charge me 32 euro's to read it. Shan't be bothering with that as its not that critical! Been in the marine industry 40 odd years and never come up against this before. I will ask around my peers and if I find an answer I will let you all know.

Thanks,

Paul.

[Paul KempParticipant @paulkemp46892]

Well it seems the flange in question is non standard. Indeed a DIN 225 does exist and it has 12 off holes but only 16mm on a 195 PCD and the spigot diameter is different also. So once again there are established standards but it doesn't mean they are used! The unit in question carries Class approval as well so it obviously doesn't matter to them either! Also seems the only way to view the complete DIN standards is to pay!

Thanks for the suggestions though.

Paul.

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