triangular seal without gland 1

[ColinScowen]

I have 2 housings. One housing has a seal pressed into it, to seal a shaft that goes through both housings. Sealing between the housings is done by an o-ring, compressed between the two housings. This causes me problems in assembly, as this o-ring often gets cut or damaged when the two housings are brought together.

Since I have a machined face opposite the shaft seal, in the other housing, I am thinking of getting rid of the o-ring. I want to add a triangular profile around the diameter of the existing seal, to mate with the machined face opposite.

All of the design guides I see are for gland based o-ring seals. Does anyone know a source for design guidelines for triangular seals?

Help would be much appreciated.

 

[CESSNA1]

ColinScowen:
Does the O-ring sit in an O-ring groove in either the seal or other housing? If it just an O-ring on the surfaces you will have problems. O-ring suppliers can give you recommended practices for O-rings. A metal to metal seal that you propose is possible and is used in some instances. A metal to metal seal requires very flat surfaces.

Regards
Dave

 

[ColinScowen]

Dave, no, there is no groove. Sorry, I guess I didn't write the first post very well.
I am not after a metal to metal seal, I want to combine the oring with the existing seal that is pressed into one of the housings, the seal that also seals the shaft.
I would then send the new design seal, incorporating the oring, to the current supplier of the existing seal.

 

[CESSNA1]

COLINSCOWEN: If I understand you want one peice with a shaft seal and a flange seal that you can assemble. If you use an O-ring then a groove is recommended. As an option an RTV seal can be applied to the one flange. I recommend using automatic equipement to do this because the seal must be cery accurately installed. The surface must be clean, dry, and oil free when installed because RTV adhesive properties are poor. Automobile manufactures use thie method on valve covers and oil pans. It works well in that application. Once cured the flange with the shaft seal and the RTV seal can then be assembled to the mating piece. I would still prefer either a gasket or an O-ring groove and O-ring.

That is my two pence

Regards
Dave

 

[Eltron]

You could also put a recession in the hole that your shaft feeds through. Match the diameter of the through-hole to the ID of an o-ring. Match the diamater and the depth of the recession to the recommended gland size for the o-ring. When you compress the the two flanges together it should squeeze the o-ring on the shaft giving you a seal on both the shaft and the flanges.

Having said that, I would recommend that you put a proper shaft seal in place and machine the correct gland for your flange sealing o-ring. It will cost more and take more time, but you will love me for it in the morning...

Hope that helps.

 

[Cockroach]

Use the Parker-Hannifin O-Ring Handbook, ORD 5700 for gland dimensions. You can find this online at their website.

For the shaft seal, be careful you identify the proper gland, static, dynamic (industrial, recipricating) or rotary. Obviously the flange is a Face Seal.

Parker lists the recommend gland geometry and elastomer squeeze in these seal applications. I personally recommend the textbook for ANY elastomer application.

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