Regenerative logsplitter valve

[dynasim]

Has anyone every a logsplitter valve such is described below. I am designing a diy logsplitter, and this seems like just the ticket. However, I'd like for someone else to have been the guinea pig!

Just curious

Thanks in advance.
Chris

Prince LSR Rapid Extend Logsplitter Valve - Cylinder Services


High speed performance with a 3 - 4 GPM pump!

Special Regen Position for blazing fast extend stroke
Requires only 3 - 4 gal. reservoir
Can use small tractor hydraulic system
Relief valve adjustable up to 3500 PSI
Handle can be installed "up" or "down"
Pressure-released detent on retract

HOW THE LSR VALVE WORKS:
Just press the handle all the way in for high speed "Rapid-Extend" performance. The cylinder will split many logs in the fast mode, but if it can't, just pull the handle back a little and get the full power of your cylinder to break the split open (about 4 times the force of the high speed mode). This motion will become "natural" after just a few splits. Then shift into the detented retract position and reach for the next log. NOT FOR USE WITH 2-STAGE PUMPS

PART NO.
PRINCE#
DESCRIPTION
PSI
MAX GPM
WT.

20-3060
LSR-3060-3
3/4" work posts, 1/2" in & out
3500
4 in, 25 out
12



TYPICAL PERFORMANCE with a 3 GPM pump, and a 4" bore cylinder with a 2" rod:

Rapid-Extend speed: 3.7" per sec. (24" in 6.5 sec!) Full bore speed: .92" per sec.

Rapid-Extend force: 7,850 lbs @2,500 PSI Full bore force: 31,400 lbs

Retract speed: 1.22" per sec.

 

[kennyd]

I have not seen this!

WOW

I am familiar with how the regen function works in loader valves, so it sure make sense to me how this would work in a logspliiter.

This could almost end the debate over 3PH vs. stand-alone splitters do to speed problems with smaller tractors.

Kudos to Prince for this valve...and @ $90.00 the price is sure right!

 

[Q-Saw]

Yes, I've been looking at the regenerative valve concept. There is an interesting thread that discusses them at the Arborist Site forum:

http://www.arboristsite.com/showthread.php?t=79311
(including an excel spreadsheet hydraulic calculator)

Sun Hydraulics also has an informative information sheet titled "TECHNICAL TIPS: REGENERATIVE VALVES" available as a PDF file at:

www.sunhydraulics.com/PDF%20Files/INT%20Line%20Mount/int_assm_regen.pdf

Remember that these valves only work with single stage pumps.

I have a Wallenstein Splitter that mounts on my 3PH, and I use the hydraulic outlets installed for the backhoe to feed it. So, I'm thinking this will be a nice upgrade for my splitter as my Kubota L3400 doesn't have a huge hydraulic flow (I think 6 or 7 gpm).

If I had known about this valve when I bought my splitter, I would have bought the larger model for more splitting force (tonnage). As it is, I bought a model down from the one I wanted because I was concerned about cycle time. I've been quite pleased with the splitter, however and only had a few large (24"-30" dia) crotch (branch) sections of ash that I had any difficulty with.

Marty

Portable Sawmill in Michigan

 

[rdbrumfield]

want speed with a low volumn pump? How about an accumulater. It charges while you are getting the wood on the knife and releases as soon as you touch the lever. Will be some hesitation if it doesn't split on first contact as the pressure builds back up, of course might be a bit wild, wouldn't have speed control, would have more of a spongy feel and pressure lag after initial release. Keeps body parts well away lol.

I have used this very valve on a dumptruck I built. Liked the idea of having a valve that kicked out when powering down the bed. I know, why power down, just faster is all and I did use it for picking up a few things from time to time. by raising the bed and chaining to what I needed picked, I was able to lift things by powering down.
I have to say about the advertisement of the valve. Nice piece of bs. 3gal a min in a 4 inch ram is 3gal a min in a 4inch ram, doesn't matter how big a valve is. Think about it. When you crack any valve just a bit the oil flow is smaller than when fully engaged. When pressure is at full popoff in the bypass, it is the same no matter how open the valve is.

 

[dynasim]

rdbrumfield,

I think these valves use an eductor to draw, and pressurize, oil from the downstream side of the valve to to make the the flow on the to the cylinder higher.

I don't think their advertising is wrong. I just didn't know if they work, in practice.

qsaw,

The pdf is interesting. I had not thought about the limitation on the amount of oil(because of the volume difference in shaft side vs not).

Thanks to all for the feedback.

Chris

 

[SPYDERLK]

Remember that these valves only work with single stage pumps.

Why wouldnt they work with a 2 stage pump?... Dangerously high speed but they should function.
larry

 

[dynasim]

Spyderlk

I think the eductor(which is just a small, special, orifice) won't allow much more oil than the design rate to pass. They are made to take the full pressure drop at the design rate.

If you attempt to put to much flow to it, the relief valve will pop every time you use the regenerative circuit.

Chris

 

[skidsteer.ca]

Unless I'm misunderstanding this.. the pump would only have to pump enough oil to fill the volume of the cylinder rod to fully stroke the cylinder at low pressure.
The balance of the oil to extend the cylinder would come from the rod end of the cylinder. The rod end oil is normally returned to the reservoir, but in the case of this valve it is being diverted into the base end of the cylinder by the special valve.
So long as the cylinder can move quite easy this will work. The cylinders power would be the same as if its bore was equal to the rod diameter.

Once the pump pressure gets up to a certain level, say 1500 psi, then the valve kick out of "hi flow" mode and returns the rod end oil to the reservoir, the travel speed slows down and the cylinder regains its full pushing force.

This should work great anywhere during the stroke when the cylinder can travel with little resistance. If it was tough going all the way it would be of no benefit
Ken

 

[Steve_Miller]

Regenerative circuits are used mainly in high cycling circuits where multiple functions are going on at the same time and thus allowing the retracting cylinders to recycle their oil rather use pump volume. This allows the hydraulic pumps to be sized smaller as the retracting cylinders oil can be used to aid in its return thus allowing the pressurized oil to be used elsewhere in the system. This type of circuit is only used on cylinders that are retracting without really doing any other work other than retracting to there home position. As the previous poster stated, its of no benefit if you need force in the retracting direction as the regenerative oil has no pressure component to speak off. A wood splitter function is a similar situation as long as it is not a bidirectional splitter. The cylinder is just retracting to then power through the wood again. If there were a log lifting circuit that was taking place as the splitting cylinder was retracting this would be a simple version of a regenerative circuit if designed that way. The retracting cylinder oil can aid its return while not stealing the extra volume from the log lifting cylinder. Make any sense or should I just shut up now.

Steve

 

[dynasim]

On the valve listed, the regenerative circuit is actually on the extend function, and apparently, produces about 500 psi of force. When the it hits the log, I think you are supposed to go to the non-regenerative position.


Chris