Tolerancing Double-Tapered Seal Ring
Tolerancing Double-Tapered Seal Ring
(OP)
I need help! I'm making a drawing for a centrally ribbed, double-tapered symmetrical seal ring, and I need advice for specifying geometric controls. The basic geometry is shown in the attached file, but basically its a hollow ring that's tapered on the OD on both ends and that has a rib on the OD centered along the length.
Functionally, the important characteristics are that the tapers be coaxial to each other, that the faces of the rib be parallel, and that the tapers be perpendicular to the rib. My problem stems from this being symmetrical, so there's no preference for one side versus the other being a primary datum, and I have to admit lack of experience dealing with compound datums and such.
Thanks in advance...
Functionally, the important characteristics are that the tapers be coaxial to each other, that the faces of the rib be parallel, and that the tapers be perpendicular to the rib. My problem stems from this being symmetrical, so there's no preference for one side versus the other being a primary datum, and I have to admit lack of experience dealing with compound datums and such.
Thanks in advance...





RE: Tolerancing Double-Tapered Seal Ring
In this case, you could use either face of the rib or either end of the primary cylinder as a datum, depending on how the part is retained and used.
I'm guessing it's made of an elastomer, so you'll probably want another datum comprising a cylinder through the center, with a note about measurements with x dia cylinder through, and resting on datum y.
You'll also need to specify the allowable mismatch at the mold's parting line, and a limit on flash trim.
It may be helpful to scrounge an inspection drawing for an o-ring, a quad ring, or a Greene Tweed T-Seal, for reference.
Mike Halloran
Pembroke Pines, FL, USA
RE: Tolerancing Double-Tapered Seal Ring
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Tolerancing Double-Tapered Seal Ring