I need a hydraulic wizard

[tuke]

Hi all,

I bought a new hydraulic pump from northern it's a Haldex Hydraulic Pump — 22 GPM, 2-Stage, and of course it has no paper of any kind with it:censored: so I found there website and i found that these and similar pumps come factory set at only 650 psi.? it's rated for 3000 psi. Must be a safety thing, so how do you beef it up where it belongs? i have a pressure gauge that goes to 5000 psi to test with. But would like someone to give me some of there wisdom before i have to learn the hard way.

Thanks Tuke
:greenchainsaw:

 

[mga]

two stage pump...i have the same one.

the pump, at factory settings, will do the trick and more. it hasn't failed me yet. besides, they advise not to tamper with the settings on the pump.

3,000 psi is more than enough to split even the toughest wood.

 

[Chuck Diesel]

I bought the same one for my splitter and right out of the box it should be set at 2250 psi on the push and 650 psi for the detent, depending on your valve settings.

 

[mga]

some info on the pump:

http://www.hbus.haldex.com/products/documents/hi_lo_pg_rev1203.pdf

 

[George G]

Their is no relief valve in the pump. What is set at 650psi is the unloading valve. The unloading valve unloads the hi-vol side of the pump. The hi-psi side continues to supply oil to the cylinder.

 

[drmiller100]

in other words, just use it the way it is without changing anything.

it will work just fine.

 

[tuke]

wisdom

some info on the pump:

http://www.hbus.haldex.com/products/documents/hi_lo_pg_rev1203.pdf

Page 5 is where i read the 650psi, but thanks to you all now i understand what it means. When i read it, it had me wondering.


thanks for the wisdom, guy's,,,tuke :greenchainsaw:

 

[kevin j]

With a gauge, you may be able to increase the 650 psi setting a bit, if you have enough engine hp. The higher the psi, the more hp it takes to turn the pump, but the more force you get at cylinder before it unloads down to low speed. So the higher you can set it, the more wood it will split at high speed.

Keep increasing it until you run out of engine hp. Then back it out a bit.
I've had some set at 900 psi because the engine was big enough. Splits almost everything at high speed, which is REALLY nice.

k

 

[cabinman]

kick down

With a gauge, you may be able to increase the 650 psi setting a bit, if you have enough engine hp. The higher the psi, the more hp it takes to turn the pump, but the more force you get at cylinder before it unloads down to low speed. So the higher you can set it, the more wood it will split at high speed.

Keep increasing it until you run out of engine hp. Then back it out a bit.
I've had some set at 900 psi because the engine was big enough. Splits almost everything at high speed, which is REALLY nice.

k

Kevin Iam lookin at the 28 gpm 2 stage pump, With more power than needed,. My Question is how high can I crank on the kick down screw before I Break sompthing? If I change the spring and go alitle higher? whats gona break first? Do you know of a 2 stage pump higher than the 28 gal? The engine is a 22.5 hp diesel, Equal to about a 35 plus hp gas engine,. Thanks Eric

 

[kevin j]

Eric:

-22 hp diesel is really 22 hp. Gas or diesel, hp is hp. IF both are rated hp at 3600 rpm. maybe one is rated at different rpm though. have to ratio back for the speed difference. Any mfr data on rated speed? might be 3000 rpm or less? then I will give info on how to figure torque.
I am assuming all data is at 3600 rpm for now.

-22 hp would be one sweet package. It would take the 28 gpm pump at 3600 rpm to about 1100 psi for 20 hp. 700 psi is 12 hp, 900 psi is 16 hp.
-Unfortunately as you are finding, when it shiifts down to 7 gpm, and runs to 2500 psi, it is only using 11 hp.

I have the same scenario with my 18 hp. (I will actually run it about 2500 rpm where it is smooth and quiet, then about 20 gpm) I want something that runs 28 gpm, then shifts down to say 12 or 14 gpm, not to 7 gpm. I don't know of anything. The high volume, mass production stuff stops at 28 gpm/7 gpm. I suspect there are other sizes, but so limited in production numbers that are price prohibitive. A pump like this selling for $300 is a deal, due to high numbers built. A similarly complicated gear pump ordered from stock parts in a catalog but in qty of one could be twice the price.

Another scenario that I am looking into is using either two pumps piggy backed (but that is long in length) or a normal two section gear pump, and use a separate external unloading valve. Then I could pick from a wide selection of gear sections, and make up a 28/12 gpm or something like that, to use the full hp in low speed high pressure mode. That is pretty complicated for casual use, and expensive. The pump is 2x the money, and the unloading valve likely $150 or more, plus an external check valve.


SO, realistically, you are stuck with the Haldex 28/7 pump. And to use more psi, you can turn the screw in only to 700 or 900 psi I think. I 'don't think' (caution!) going higher will break something as far as casting strength, or shaft strength. The shaft would be designed for a torque approximating that of the 12 or 16 hp, so I think that is ok. Housing strength for higher psi in the big section, probably ok.

Two issues: physically getting more force on the spring without bottoming or binding, and will it be stable and not buzz or hunt or chatter. Getting another spring may be tough math. Shimming the spring is what I will look at. There still has to be some room for the spool to travel back and forth and if it gets too compressed, it may not work right. There are also stress issues in teh spring, but you could just order a few spare springs to have on hand. If spring failed, it would likely not go pieces anywhere, and it would still work on low speed high pressure mode.

I think it can be done. Is this something you are working on now or soon? I have an older 28 at home that I will use someday. Not sure if same construction, but I could pull the cartridge this weekend and think about it.

I would certainly use the big engine though, crank the unloading pressure as high as it will go, and if it can be tweaked later that is a bonus.

k

 

[drmiller100]

go split some wood.

the kick down is only 5 percent of the time, so changing ti from 650 to 1000 is only going to save you 30 seconds a day or something silly.

one thing you can do is run two pumps. hook one up direct, and then add a pulley to run another pump off a fan belt.

you can make your own auto kick down 2 stage pump. i did it.
i bought a pump that pumps 10 gpm off one stage, and 20 gpm off the other. i set the 20 gpm on a bleed off with a one way valve in the middle of it all.

 

[kevin j]

*****kick down is only 5 percent of the time, so changing ti from 650 to 1000 is only going to save you 30 seconds a day or something silly.


Not in what I split. 4 inch cylinder. Usually dead elm that is not big but very grainy and stringy. Almost every cycle goes to high pressure for several seconds. But what you describe makes sense. Not worth the effort then.



****you can make your own auto kick down 2 stage pump. i did it.
i bought a pump that pumps 10 gpm off one stage, and 20 gpm off the other. i set the 20 gpm on a bleed off with a one way valve in the middle of it all.


Can you add a sketch? I don't understand how you unload the large pump to 0 pressure. Bleed off flow control would have the large pump still at full load pressure. Where did you get the pump? If it's cheap surplus its about the right size for larger motors and what I am looking for.

tks, kcj

 

[ray benson]

With a gauge, you may be able to increase the 650 psi setting a bit, if you have enough engine hp. The higher the psi, the more hp it takes to turn the pump, but the more force you get at cylinder before it unloads down to low speed. So the higher you can set it, the more wood it will split at high speed.

Keep increasing it until you run out of engine hp. Then back it out a bit.
I've had some set at 900 psi because the engine was big enough. Splits almost everything at high speed, which is REALLY nice.

k

My 16 gpm barnes pump unloads about 500lbs. Where is the set screw to adjust the pressure?

 

[046]

good info in this thread!

plans are to upgrade from 16 gpm to either a 22 gpm or 28 gpm two stage pump. driving a 5in cylinder with aprox. 26in stroke.

splitter is speeco 35ton with 12.5 briggs... plans are to upsize hoses to 3/4 in from current 1/2in. valve body has 3/4in outlets.

I've heard both ways... go 22 gpm or 28 gpm and that my 12.5hp briggs will support either pump.

rule of thumb floating around is go 1gpm for every 1/2 HP. since cost difference between 22 to 28 gpm is only $50. much rather go 28 gpm ... if my 12.5 hp briggs can support it.

any input?

 

[triptester]

The long hex cap on ther suction side covers the adjusting screw. Remove cap and then tighten slotted screw 1 turn at a time . Check pressure after each turn. Pressures above 650 psi could cause the engine to stall. Also excessive pressure setting could damage pump.

Haldex recommends contacting factory for settings above 650 psi,1-800-572-7867

 

[cabinman]

Diesel

Eric:

-22 hp diesel is really 22 hp. Gas or diesel, hp is hp. IF both are rated hp at 3600 rpm. maybe one is rated at different rpm though. have to ratio back for the speed difference. Any mfr data on rated speed? might be 3000 rpm or less? then I will give info on how to figure torque.
I am assuming all data is at 3600 rpm for now.

-22 hp would be one sweet package. It would take the 28 gpm pump at 3600 rpm to about 1100 psi for 20 hp. 700 psi is 12 hp, 900 psi is 16 hp.
-Unfortunately as you are finding, when it shiifts down to 7 gpm, and runs to 2500 psi, it is only using 11 hp.

I have the same scenario with my 18 hp. (I will actually run it about 2500 rpm where it is smooth and quiet, then about 20 gpm) I want something that runs 28 gpm, then shifts down to say 12 or 14 gpm, not to 7 gpm. I don't know of anything. The high volume, mass production stuff stops at 28 gpm/7 gpm. I suspect there are other sizes, but so limited in production numbers that are price prohibitive. A pump like this selling for $300 is a deal, due to high numbers built. A similarly complicated gear pump ordered from stock parts in a catalog but in qty of one could be twice the price.

Another scenario that I am looking into is using either two pumps piggy backed (but that is long in length) or a normal two section gear pump, and use a separate external unloading valve. Then I could pick from a wide selection of gear sections, and make up a 28/12 gpm or something like that, to use the full hp in low speed high pressure mode. That is pretty complicated for casual use, and expensive. The pump is 2x the money, and the unloading valve likely $150 or more, plus an external check valve.


SO, realistically, you are stuck with the Haldex 28/7 pump. And to use more psi, you can turn the screw in only to 700 or 900 psi I think. I 'don't think' (caution!) going higher will break something as far as casting strength, or shaft strength. The shaft would be designed for a torque approximating that of the 12 or 16 hp, so I think that is ok. Housing strength for higher psi in the big section, probably ok.

Two issues: physically getting more force on the spring without bottoming or binding, and will it be stable and not buzz or hunt or chatter. Getting another spring may be tough math. Shimming the spring is what I will look at. There still has to be some room for the spool to travel back and forth and if it gets too compressed, it may not work right. There are also stress issues in teh spring, but you could just order a few spare springs to have on hand. If spring failed, it would likely not go pieces anywhere, and it would still work on low speed high pressure mode.

I think it can be done. Is this something you are working on now or soon? I have an older 28 at home that I will use someday. Not sure if same construction, but I could pull the cartridge this weekend and think about it.

I would certainly use the big engine though, crank the unloading pressure as high as it will go, and if it can be tweaked later that is a bonus.

k

I cant agree with the gas,.to .. diesel equsasion,..Take a look at toro grounds master 6 ft cut, The same mower is either a 45 hp ford gas. or a 28 hp mitsubishi diesel,. and they pull the sane weight , and cut the same width,.They are the same unit,..The Diesel has MUCH more torque than the gas,...IVE been there,.Iam not guesing , .So I can screw the KICK down screw tight and go split,.Iam not asking for amy gurantees,.But just your opinion,..Thanks Eric

 

[gtstang462002]

I cant agree with the gas,.to .. diesel equsasion,..Take a look at toro grounds master 6 ft cut, The same mower is either a 45 hp ford gas. or a 28 hp mitsubishi diesel,. and they pull the sane weight , and cut the same width,.They are the same unit,..The Diesel has MUCH more torque than the gas,...IVE been there,.Iam not guesing , .So I can screw the KICK down screw tight and go split,.Iam not asking for amy gurantees,.But just your opinion,..Thanks Eric

HP and torque are 2 complete different measures of power. Torque is ultimatly the number that you want to look at. Too much of it and you are breacking drive shafts that are rated for X horsepower though you can be way under that HP. HP is old school mines bigger than yours addage. I have a 3.5 HP honda running my splitter that will run all day on a tank of gas splitting oak running a 16GPM pump. Rarely does it kick into low gear. My nieghbor has a very similar splitter that has an 8HP briggs on it that burns 4 tanks of gas to my one and is forever kicking into low gear... And on top of that he has to let that motor fully warm up before putting a load against it.

 

[ray benson]

Hard to believe a Honda 3.5hp motor was equal to a Briggs 8 hp motor. And that it had more torque all while getting 4 times the run time. What am I missing?

 

[eric_271]

Hard to believe a Honda 3.5hp motor was equal to a Briggs 8 hp motor. And that it had more torque all while getting 4 times the run time. What am I missing?

If you asked him to let you look under the hood he aint gonna let you cause the honda has been bored, stroked,camd with fuel injection.

 

[gtstang462002]

Hard to believe a Honda 3.5hp motor was equal to a Briggs 8 hp motor. And that it had more torque all while getting 4 times the run time. What am I missing?

I havn't figured out where I am ahead yet, but I damn sure aint gonna complain about it. The worst part is I don't even like honda anything but it was free so I am not going to throw it away... I will run it till it breaks...