hydraulic valve

[DDDfarmer]

Hi guys, I have been searching the site in vain for the proper name of a hydraulic valve.

A while back in one of the threads about a processor somebody mentions a valve that would salvage some of the oil from a retracting cylinder to aid or speed up the retraction of the cylinder.  Dad has put together a shear firewood processor but the retraction of the main cylinder seems a little slow. 



  

Anybody remember that thread?

[beenthere]

There are regenerative circuits, that may be what you are referring to here.

A prior thread with a bit of info.
https://forestryforum.com/board/index.php?topic=41052.0

Some bucket curl circuits (as on my JD) use that circuit to execute a faster dump, but think it may depend on some weight of material in the bucket to make it work.
Google has info about the circuits/valve arrangements.

[North River Energy]

More photos of shear, if you please.

[kensfarm]

Air leak when retracking?  More flow needed for that big cylinder?  Pump stats vs cylinder requirements?  If pump is powered by belt pulleys.. change pulleys to get pump going faster.. see if it helps.  Yes.. more pictures.. that's a pretty cool wood chomper.

[Weekend_Sawyer]

I don't know but I would like to see that shear in action! What size engine are you using?

[DDDfarmer]

 

 

pump, max specs at 48gpm/2800rpm requiring 112hp  I think we have it set around 30gpm and tractor runs around 1300rpm.  not sure what the reduction is but it will slow down a 80hp diesel tractor on the max cuts.  almost stopped the neighbours 45hp on some 10" white birch



 

splitter valve, takes the 30 gpm and splits to 2x 15 gpm



 

valves, 2x is for the shear and apron drive  single is for the stand alone wood splitter



 

apron drive



 

apron deck ( wood deck folded over for transport)  hydraulic tank is built into the trailer frame 55 gallons approx.


still a work in progress the 8"x 1/2" I beam we used for the shear frame in now all bent and twisted ( recycled steel, I think it was burnt)  Apron feeder chain was salvaged from an old mill and now that the rust is worked out of it its kinked and doesn't roll over the sprockets right anymore.  work with whatcha have, its proven to work now its worth spending a few dollars on to improve.

[DDDfarmer]

Mostly Dads creation.  I got him the pump, oil, hyd fittings and some of the salvaged steel.  Neighbour gave him the trailer ( he wants to use the creation now lol) many hours debating?  ;D over what will work and what wont.   

[North River Energy]

Bravo on the pictures.
Is the ram actually slower on retract, or does it just seem slower than it should be? 
I have a similar problem with 'apron' chain kinks, and have considered a set of idlers mounted underneath to undo the kink imparted at each end of the infeed assembly.  Meanwhile, it's periodic heat, hammers and lube.

[DDDfarmer]

It just seems slow when you start cutting the smaller stuff 4-10"  BUT  after using this contraption last winter, chainsaws are only used to cut trees down and limb now  ;D  You aren't tired or sore after cutting all day.  Now for a conveyer and better dump trailer

Now that its proven its cut apart at the moment to improve parts.  I was looking at some rollers before the chain feeds onto the idler roller, something like a rock-guard on a excavator or dozer.  Chain doesn't always come off, you can use it for a whole day and it never acts up then the next day its was off every third log.  We only lubed the apron chain to get it moving freely, after that we kept it dry as to not let dirt stick to it.  The roller chains I've been using some crappy chain bar oil for them.

[North River Energy]

That being the case, and assuming the plumbing is up to it, i'd increase the flow to the shear side.  15gpm seems a bit low for that cylinder. Given what you said about the load on the tractor, might be a good application for a 28gpm 2-stage.  Rapid approach, plenty of grunt for the work.  Then again, maybe not...
Maybe check with @Stephen Alford to see what he's using on his shear?
Also some kind of return stroke control for when you have a lot of smaller stock to shear and don't need full return?

[DDDfarmer]

we run the shear cylinder once right from the pump and it was up-down-up-down  almost like there was no in-between  ;D  We have talked about doing that again and adding a second pump for the splitter but don't have a pump to add at the moment.  The return stroke control is all in the operator, there are no detents in the shear/apron valves for safety.

[Stephen Alford]

 

 
Found the safest for me was to control the shear with the knee this keeps both hands free. That comes in handy. Should point out that staying on the back side of the shear is the safest. Its run with a 453...125hp Detroit. Hydraulics run 3 infeeds one conveyor and a splitter that is 2 way or 4 way.