Hydraulic seals

[Nick1911]

I'm going to check around tomorrow, but does anyone happen to know anything about hydraulic seals?

I've got these two that are leaking quite badly.  They go around a piston.  They are off a surface grinder which hasn't been made in a long time.

They are cupped in metal.  Stamped "58 F 24 DBB" and "Universal"

OD is 1.830, ID appears to be 1 inch (metal stamping is 1.018, seal relaxed is about 0.990)  and 0.425 thick.

I'm not even sure what to call these, or how to go about cross referencing them.  Tips are appreciated!

[Jim147]

There was a place in KC that rebuilt our cylinders when I was up there can't think of the name will search for it tomorrow.

My log splitter is pouring out the pump seal need to pull it apart soon to see if I can find a seal for it.

[dogmush]

Those look more like wipers than seals but there can be a lot of variations in seal packs for hydraulic pistons. Look online for your local brick and mortar hydraulic cylinder rebuild place and take them in. The can measure and get you what you need.  There's like three places in Tampa i could get those, not that that helps you too much.

[K Frame]

Damaged seals are not a good thing.

[zahc]

Check McMaster-Carr

[230RN]

I've had a lot of seal and O-ring problems solved by Rocket Seals in Denver.

https://www.rocketseals.com/

Contact form:

https://www.rocketseals.com/contact-us/

"We stock O-Rings, Quad Rings, Hydraulic Seals, Mechanical Seals, Oil Seals, Piston Seals, Rod Wipers, U-cups Loaded, U-cups Unloaded, Hydraulic Packing, Cylinder Kits (Telescoping), Vee Style Packing, Wear Bands, Cordstock, Caplugs and more."

[Jamisjockey]

Hey buddy, looks like you blew a seal....

[K Frame]

Hey buddy, looks like you blew a seal....

Are you sure that's not just vanilla ice cream?

[Jamisjockey]

Are you sure that's not just vanilla ice cream?

 

[Nick1911]

Local hydraulics place stared at me blankly.  Said they didn't have any seals that had metal housings.  Suggested I try a bearing place.

Guy at bearing place, BDI, was very helpful.  He didn't have it in stock, but did work out that Timken part 450040 would be a good candidate. 

I'm going to take a few measurements when I get home, and have him order the part.  I did find the Timken seal catalog that he had online (here), which is also helpful.

[230RN]

Huh-huh-huh, rod wipers.  He said rod wipers.  Huh-huh-huh.

Wipes teenaged snot off upper lip.

On shirt sleeve.

 

[Nick1911]

Well... these two are the only sealing surfaces on the end of the cylinder.  There are no other seals keeping hydraulic pressure in where the piston comes through.

Maybe they are called wipers, though.  Don't know.

[Boomhauer]

Might have to try a better hyd place...find one with a crusty old bastard at the counter. The first seal of a hyd cylinder that keeps dirt and schmoo out is indeed a wiper seal. For us they are typically a douple lip seal with a metal case (and metal cases are indeed common for these kinds of seals) but I haven't seen your kind yet. Maybe those are old school the kind we deal with are much flimsier looking but then our cylinders have a lot more seals to do the sealing work and the wipers are more of an environmental seal than a pressure seal

Sent from my SM-G955U using Tapatalk

[lupinus]

Good luck. Odd are you may have to make something work if you (likely) can't find the right part.

[Triphammer]

Poking around the net I found a picture of this with two additional inner ridges that are obviously worn off yours. They called in an "axial face seal"

[dogmush]

Poking around the net I found a picture of this with two additional inner ridges that are obviously worn off yours. They called in an "axial face seal"

It's not an Axial Face seal.  Among other things, those are used for rotating shafts, not oscillating ones.  This would be completely the wrong application.

Nick, I just looked in the Timken catalog, and a 45 series seal is a radial lip seal, designed for a rotating shaft, and oil pressure in the single digits. (Like up to 7 PSI, if you keep the RPM slow)  If those things are actually holding the Hydraulic pressure in your piston, there's no chance a little lip seal will work.

Are you sure there isn't some kind of ring packing down in the end caps on the cylinder?  Do you have any pics of the piston and end caps?

[dogmush]

FWIW, Here's the Universal Seal Co Catalog.  They're Canadian, and still in business.  I've bought their stuff before. http://www.universal-seal.ca/Catalogue#book5/page1

I still think that's an out of production rod wiper. 

[Nick1911]

It's not an Axial Face seal.  Among other things, those are used for rotating shafts, not oscillating ones.  This would be completely the wrong application.

Nick, I just looked in the Timken catalog, and a 45 series seal is a radial lip seal, designed for a rotating shaft, and oil pressure in the single digits. (Like up to 7 PSI, if you keep the RPM slow)  If those things are actually holding the Hydraulic pressure in your piston, there's no chance a little lip seal will work.

Are you sure there isn't some kind of ring packing down in the end caps on the cylinder?  Do you have any pics of the piston and end caps?

Here's pics of what I have.  I've remove the whole front of the cylinder assembly and pulled the piston from the cylinder.

[Nick1911]

And I just figured it out.  The other pressure port is just on the far side of the brass bushing.  I thought the port in the cast iron piece above was the second pressure port.  I think it's not.  Doesn't make sense that it could be.

The brass busing... is the hydraulic seal.  Then follows a wiper, and a void with a return line cut in, and a final wiper.

The problem here is that the brass busing has opened up over it's 70 year life.  While the piston rod mic's out at 0.968, the bore of the busing is 0.980.

[dogmush]

Does that thing spin too? That almost looks like an oiled bearing and two oil seals. Strange.

What goes in that -AN fitting on the endcap?

[Nick1911]

Does that thing spin too? That almost looks like an oiled bearing and two oil seals. Strange.

What goes in that -AN fitting on the endcap?

It does not.  The brass bearing was pressed into the end cap.  A steel line runs the the AN fitting, and disappears into a large control valve.

At this point, I'm thinking about making up another brass (or maybe bronze?) bushing, bored at... 0.970?

[dogmush]

Does this power in both directions?  Or does it have some kind of spring or gravity return?  I assume it was leaking before you took it apart, or we wouldn't be talking about this.

Are those u-cups or v-seals on the end of the piston, or just wear rings?.

If I were going to the trouble of making something to seal that, and it's under pressure, I'd get a cup seal, and machine the Ned cap to retain it. Maybe  fab a retainer.

Are you paying someone to fab this, or making it yourself? Labor could be cost prohibitive.

ETA: slip fit on the piston will be like .001" or .0005" over.

[Nick1911]

Does this power in both directions?  Or does it have some kind of spring or gravity return?  I assume it was leaking before you took it apart, or we wouldn't be talking about this.

It's powered in both directions, no springs or other return mechanisms.

Are those u-cups or v-seals on the end of the piston, or just wear rings?.

I believe they are called U cups.  I just swapped those out today with a nearly identical product: this.

If I were going to the trouble of making something to seal that, and it's under pressure, I'd get a cup seal, and machine the Ned cap to retain it. Maybe  fab a retainer.

I'm all ears, and I'll definitely look into it.  Any suggestions on parts in particular?

Are you paying someone to fab this, or making it yourself? Labor could be cost prohibitive.

DIY.  It's my surface grinder, and I'll be doing the work in house.  Only cost is materials.

[dogmush]

I'm all ears, and I'll definitely look into it.  Any suggestions on parts in particular?

Get some U cups of the appropriate ID and either turn a cap from steel, or put grooves on the inside of that brass bushing. then install a retainer.  I'd lean towards making a cap or plug and internally thread that end cap, but I'd want to track down what that line and vented disc between the seals was doing.  You might be able to make a cap and just put it on the very end of that cast piece.

Look here: http://www.universal-seal.ca/Catalogue#book5/page30  On the picture of the "rod application" you need to make the end cap.  To be very specific I'd have to fiddle with the machine.  If you're correct that the brass piece WAS the seal, you can just turn a groove in it, put a U cup in, and reinstall everything with new oil seals.  It held the pressure before, it should still hold it.


ETA:  You can see in that picture how, unlike a lip seal, radial seal, or wiper, the U cup is designed so that as the fluid pressure increases, it's pushed harder into the housing and rod, and seals better.  The two on the piston will have to oppose each other.

[Nick1911]

I like it.  I'll see what I can find for a seal, then determine if I have enough meat to put it within the original brass piece.  Ideally, I'd like to keep the spacer and other line as they were.

Thanks for the help!