×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Help understanding this pneumatic connection.

Help understanding this pneumatic connection.

Help understanding this pneumatic connection.

(OP)
Howdy all,

I'm designing the tooling to test a pneumatic motor and I'm stumped by this connection in the pictures below. It's a 2.25" OD with two grooves. The first grove, the larger one I thought was an O-ring gland, but it's a bit narrow at .091 inch and way too deep at .125 inch. The second, smaller groove is just .050 inch wide and .080 inch deep. I designed a connection that "works" using a couple stacked O-rings (size 033) and uses the narrow slot to fit some machined L-angles with bolts to hold the attachment sleeve in place. I'm just not happy with my design and I might make a better connector if I knew how this connector is supposed to work. This is for the pneumatic actuator motor on a 747 leading edge flap drive.

Anyone familiar with the mating connector that matches this port?

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

RE: Help understanding this pneumatic connection.

My guess is that the narrow groove is for a pin or "U"-clip (essentially two pins) to pass through in order to lock the fittings together.

RE: Help understanding this pneumatic connection.

what does the mating a/c part look like ? defined by some hydraulic system part number ?

another day in paradise, or is paradise one day closer ?

RE: Help understanding this pneumatic connection.

(OP)
After fiddling with my parts I came up with a small modification to my design that made it workable. I originally was just going to use these bent clips to hold it in place, but after the machinist gave me the parts (and before I gave it to the tech to use) I tried installing it and there just isn't enough space to screw in the bolts. (green part is a model of the connector.) I slotted two of the holes so I could have the fasteners already installed and then just pivot the brackets into the slot and give the fasteners a quarter turn and it should work.

I think if I was going to do this again I would fab the mating part to receive a flat 'U' shaped bracket that goes in the narrow slot like Compositepro was thinking of.

rb1957,

I wish I knew, that was my original problem. like there's a plan to hook this is up and I don't know what it's supposed to look like. It's 46 psi air.

Thanks all,

-Kirby



Kirby Wilkerson

Remember, first define the problem, then solve it.

RE: Help understanding this pneumatic connection.

We're is the O-ring? How would you assemble the coupling in the coupled case? I meant a U-clip where the pins go through clearance holes in the mating part, parallel with the groove, and perpendicular to the coupling axis. Like the pin on a hand-grenade.

RE: Help understanding this pneumatic connection.

That second narrow ring looks very beaten up though.

The top picture makes it look like the are three rings but the second one only two rings?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Help understanding this pneumatic connection.

The abuse on the edges of these grooves is terrible. These parts may be out of damage limits. Check the SRM/CMM before investing time in making mating pieces if they're already scrap.

The first groove looks too deep for o-rings but the service may be too hot or move too quickly or too little lubrication for O-rings to work there anyway. If it still needs to seal, then something akin to a piston ring may be what you're looking at.

Why the heck don't you know everything about this assembly down to the seals, packers, fasteners and mating parts? Don't you have a CMM? If there is any hope of reassembling this actuator and recertifying the repaired unit, then it should be safe to assume that you're working with a component overhaul shop with the requisite tools and repair data to deal with this. From that, I can infer that somebody is NOT in the dark about how this part works, so you should find them and have a chat.

RE: Help understanding this pneumatic connection.

(OP)
LittleInch,

There are two grooves that you can see in both pictures. The third groove-like feature is just the machined stub of the fitting which in the second picture is mostly covered by weld bead.

WindWright,

This is the part we have in and what we're looking at is the opening where it connects to the aircraft. I don't have the aircraft (a 747), so I can't walk over and look at how this connection works or what the mating part is. I could try and find the AMM which probably has details about installation and removal, but all I have is the CMM which doesn't detail external parts. So my point in posting here is to ask if people are familiar with this type of connection and clue me in as to how it works. This is a new repair part development, so we're learning it.

As to the damaged edges of the groove, I think this groove is used to hold a retaining clip which is why it gets dinged up. The damage is less than .005 inches and we will ensure it meets the CMM airworthyness requirements before we certify it.

Thank you all for your feedback.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

RE: Help understanding this pneumatic connection.

All speculation. Some initial sealing device (tool) to aid in applying sufficient force to allow proper ease of installation of U clip as suggested by Compisitepro. Without tool, I imagine efforts to hammer the locking U clip into position. Removal of U clip under stress requires screwdrivers, punches or chisels. Damaging unit as seen. Good luck

RE: Help understanding this pneumatic connection.

(OP)
Thanks for the sketch moa1. Someone found a mating part that was used for testing on a different stand and it looks like half a V-band clamp that presses against the face with a couple of blocks that clamp around giving a tight fit in the larger slot. See the pictures. This seems like a much better design then what I had. Here's what I came up with.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close