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Distance between tapered pins

Distance between tapered pins

Distance between tapered pins

(OP)
Hello. I'm designing a shaft - hub joint with tapered pins. The problem is that the hub is quite short and I have to use two pins due to the high torque. Is there any reccomendation about the minimum distance between pins?

Thanks

RE: Distance between tapered pins

What diameter shaft?
What diameter of the pins?
What diameter of the (pulley) load flange?
What amount of load on the shaft-pulley?
How are you going to "fix" the tapered pins from being vibrated out of their holes?

RE: Distance between tapered pins

(OP)
Hi, is a 200 mm shaft with 2 x 50 mm diameter pins. The torque is 70000 N·m applied with a quarter turn electric actuator.

We use to tag weld all parts under vibration.

I don't know if there's some exact way to calculate the distance between pins. If not I would appreciate some general reccomendations (like the pin diameter should be from 0,2 to 0,3 the shaft diameter or distance between bolts 2,5 times the bolt diameter). Is there something like this for tapered pins?

Thanks in advance.

RE: Distance between tapered pins

Why are the pins tapered? The taper will help the pins to writhe out of the holes.

What is the advantage of this horrible setup over a taperlock or something you'd find in a catalog?

Can you sketch it?

Anyway it is a nice little FEA problem.

Cheers

Greg Locock


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RE: Distance between tapered pins

Rotate one of the Dowel Pins 90 degrees to remove it from the shear plane of the second.  This means you will need to have two holes orthogonal to eachother, Hub & Shaft.

Depending on your exact Dowel Pin, Shaft OD and Hub ID, the distance between centres will be governed by your maximum peek torque input load.  The shaft can be analysed as a stress concentration between holes, classical equations are in Roark's.  I would prefer to do a FEA model on that, then check the output based on the classical model.  You should be within 3% error.

Hope this helps.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

RE: Distance between tapered pins

Does the load reverse?

RE: Distance between tapered pins

Unless it is the design intent to plastically deform something when installing the pins the load will not be distributed between the pins.

The second pin driven will in all likelihood take all the load.

So you might as well just design a single pin connection.

RE: Distance between tapered pins

what material are you using for the pin? Whats it's maximum allowed shear pressure?

NX 7.5
Teamcenter 8

RE: Distance between tapered pins

Cockroach, you really are amazing.

Regards,

Mike

RE: Distance between tapered pins

(OP)
Hi, I would try with a FEM model and the indications from Cockroach (I was amazed) and aslo will check what MintJulep said. If I come to some conclusion I'll let you know. But will have to wait, now I have 4 days off. Feliz vispera de todos los santos (happy halloween for english people).

RE: Distance between tapered pins

WalterKe, on the computation sheet, top, I indicated material as AISI 4140/4130 HRc 18-22.  This is equivalent to L80 alloy steel.

Thanks for you kind words SnTMan & ManoloGalarraga.  I believe this is the whole purpose of the forum, to make it a learning experience and capture from others on a particular problem.

Good luck with the design.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

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