O-Rings: How do you mate them into an assembly?

[tommo]

Folks,

I have generated o-rings using the SWEEP function and want to mate them into my assembly.

As mates can only be generated on a planar, cylindrical, spherical, conical surfaces - what tricks do you guys use to locate o-rings in assemblies?

I know this sounds like an assignment question - be assured it's not!

Thanks

 

[darnell]

We create ours with a circle, centerline and revolve. We mate them with the axis and planes

 

[Heckler]

Did you make the o-ring in its compressed state? I would take Darnell's approach and insert a reference plane and axis.

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 2.0 & Pro/E 2001
Dell Precision 370
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Do you trust your intuition or go with the flow?

 

[mike57]

I just inserted an o-ring into my assembly. What I used this time was a distance mate from the origin which I positioned in the center of the o-ring to the side of the groove and a distance mate from the origin to the cylidrical surface below. I made the o-ring the same way that you did using the sweep function.

Mike Elias
Wellstream International Ltd.

 

[MElam]

Where is the origin of the o-ring?

A few best-practice tips:

Create the o-ring centered on the origin (in a sweep, that's the path, not the profile). This will place the origin and reference planes in a perfect location for mating without needing distance mates. Every time you locate something using a dimension, that's one more variable to change if the design changes. I try to only use distance mates if the distance is an important, driving dimension.

Create the o-ring as a revolve instead of a sweep (unless it's not circular!). Revolves rebuild faster than sweeps.

 

[CorBlimeyLimey]

If your O-ring has configurations, place a Parallel Plane at Point, using a main plane & a tangential point in the sketched circle, used to create the revolved section. Name this new plane "Seating Plane" or similar & use it to mate the O-ring to a face in the part. This way if you change the x-section size (configuration) of the O-ring, the seating plane will remain "tangential" to the x-section.


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[macduff]

I have our companies in a compressed state per Parker standards. I created 3 part files with design tables and compounds (Military no.'s) for 070, 103 and 139 cross sections and have them loaded through the toolbox browser. Just drag and drop into an assembly and mate with concentricity and a tangency against the gland. I know I could of created one part file, but it’s easier for maintenance.





Macduff
Meggitt Airdynamics Inc.
Senior Designer/Checker
Dell Precision 370
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[CorBlimeyLimey]

I used to use the Concentric/Tangent combnation, but found the Tangency to be too flakey. I switched to using the parallel plane above & have never had a problem since. It's much easier to select as well ... can all be done from the FM tree ... no more zooming in to select the curved surface.


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[tommo]

Thanks for the replies folks.

Making the o-ring using the sweep function isn't "the way to go"

Can't believe I went to all that trouble when a revolve was the obvious answer.

What a great site - you are never on your own!

Pat

 

[meintsi]

O-rings are best modeled with a configuration for each type of application. (male gland, female gland, etc...)

We start with a very small dia. revolve sized to be inside each configuration to use as a base. Then the relaxed state revolve is added over the base revolve. Each additional configuration then adds a new revolved sketch which mimics the shape of which they are to be inserted into.

O-Rings in a working/compressed state will always have at least one flat surface (if ever so small) (kinda like a rectangle with rounded edges in the simplest case) that we use for mating purposes. That way, one concentric and one coincident mate takes care of everything.

Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]

 

[btcoutermash]

Do not forget that you can also use sketch entities and intersection points of sketch entities to mate parts in assy.