linear compressed air feed system

[petedie]

Hello,

I have 20+ carriages on a single 3m gantry that require electrical and pneumatic power. I'll be using main PLC to control slave PLC on each carriage using industrial WIFI signal. I can get the power to each carriage using conductor rails (street car idea) but how can I get compressed air. I don't have room for 20+ cat tracks so I'm looking for a something that can be attached to the carriage linearly... One idea was to purchase a rodless cylinder with extra pistons and port them. Would anyone know of any other product out there for this job?

Thanks
Pete

 

[MikeHalloran]

Or you could festoon the air with a tee on each carriage and a loop to the next carriage. O-ring sealed push-on connectors and nylon tubing should allow the small amount of rotation that's necessary to deal with the loops twisting.

The trick is, the loops have to be long enough that the tee runs are oriented normal to the track, not parallel to it.



Mike Halloran
Pembroke Pines, FL, USA

 

[petedie]

Hello Mike,

unfortunately that won't work as all except for one carriage can be working on one side and then you'll need 3m long loop. It's the same reason why I went with the conductor rails idea for electrical power...

Thanks
Pete

 

[MikeHalloran]

Okay, since you've got the power on each carriage already, you could give each its own compressor.



Mike Halloran
Pembroke Pines, FL, USA

 

[petedie]

Hello Mike,

each carriage is ~3" wide, this is a long gantry with many small carriages that must accelerate extremely fast plus to plan is to run low voltage to achieve the required motion

Pete

 

[MikeHalloran]

Okay, the rodless cylinder with multiple drilled pistons is sounding better, or less awful.
I'm guessing you'll need more than one because of the effective axial length of the seals.
Because of the extra seal band length required to go over all the pistons, you can't just add pistons to a generic cylinder, so you'll have to work with the factory, or buy an extra long cylinder to shorten and hack.





Mike Halloran
Pembroke Pines, FL, USA

 

[ornerynorsk]

A picture is worth a 1000 words. Do you have a sketch or drawing you could upload to better understand the arrangement of your machinery?

A rodless cylinder working as an interim reservoir could work, what kind of stroke do you need to accomodate? Not sure I understand why you don't have room for a festooned airline if there would be sufficient room for a rodless cylinder ???

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[petedie]

I'm actually thinking of ripping the piston out of the cylinder and making my own carriages for each gantry head (carriage). Sorry no picture as this is all in concept/handsketch mode right now... The maximum stroke is 3m and I'm looking at 25mm bore cylinder to supply all the gantry carriages (fed from both sides).

 

[hendersdc]

You might consider a separate air line to each carriage guided by something like an IGUS e-chain.

http://igus.com/wpck/default.aspx?pagename=productoverview_EC

 

[MikeHalloran]

I'd be inclined to just drill a big hole through the regular piston, and attach your carriage in the same way as usual to the carriage that comes with the cylinder.

My point was that the sealing strip rides out and back a bit from its normal plane over 4 or so rollers within the linear cylinder's piston assembly, so you'd need an extra long strip to seal multiple pistons. I don't think it's a generic material that you can buy in bulk, so you'd need the cylinder mfgr to make it for you. If they're going to that much trouble, I'd ask them to also drill and install multiple piston assemblies. That way you can buy the thing as an assembly and just bolt it to your carriages.







Mike Halloran
Pembroke Pines, FL, USA