Hydraulic power unit info needed

Hello,
Today I grabbed this hydraulic unit to use for a press project I’m building. My question is can this thing really be this simple? Or am I missing something? I have two ports which I’m assuming are exit and return. Am I correct on this?

Below is a link to pics of the unit
Any help is greatly

31285394-B49-F-43-DB-B125-D2275-D6-FEF3-E — imgbb.com
A6-A22824-543-D-4-F75-8010-87-AC95-D23950 — imgbb.com
DE462-E95-72-D3-4-A5-B-9796-B707446377-FF — imgbb.com

It is pretty simple, but of course you're going to need a control valve and pressure bypass to complete the deal. Unless it's a pressure compensated pump..which it doesn't appear to be, your valve must be center open so fluid is returned to the tank when the valve is OFF. A return filter should be in the plan as well.

Stuart

Thank you atomarc, I was confused by the simplicity of it for sure. And thanks for the info on the valve. Can you elaborate on the center open valve? I’m not that knowledgeable when it comes to hydraulics so excuse my ignorance. I’m assuming your talking about the log splitter style valves?

Does it even work properly ?
The smashed breather vent/fill cap and dirt make it appear to be a "junkyard find".


Pull that motor and see what comes up out of the tank with it.

Digger your not far off. It was picked up for $20. The motor appears to need rebuilding as when you plug it in it barely turns.

Whats the pressure range of th gauge.....unit usually runs at about 1/2 the gauge.....seems a big motor,unit may be high flow ..only needed if your press has 10" bore cylinders.....I would find a two way valve /open centre with around 1/2 to 3/4 NPT ports,as mentioned as these are the most common by far.Both ends of the cylinder will have oil inside,which means you wont need any retracting springs ,and the cylinder wont go rusty ....By all means strip the motor and pump ,and check out before going further......motor barely turning may mean a plugged hydraulic circuit.or maybe grunge inside the motor.Clean the tank too....Be aware the motor may need to turn one way,check that before trying it out...if the pump has a non return ,wrong rotation may bust something,as well as burn out the motor.

The unit appears to be a 120 A.C. volt power unit, if that is the case then it most likely is a lower volume pump unit( gallons per minute)
It probably will push up to 2500 psi, just be careful when test running as if there is oil in the reservoir then you could have quite a mess with oil pumping out the high pressure outlet side of the unit. You can route a hydraulic hose from pressure to tank return for testing.
The motor turning slow could be a bad capacitator. Baldors are great motors.
To answer your question about the open center valve, when the spool in the control valve is moved into a function, example two way hydraulic ram pushing the rod out. The supplied oil is filling the ram cavity and forcing the piston on the ram to travel outward. The same would apply for the ram to retract, when the spool in the control valve is moved into the center closed position (no oil flow to either direction of the ram) then the oil being pumped must go somewhere, it is the open center of this type of spool valve that allows that oil to return to sump/oil reservoir, there is generally a pressure relief valve also built into the control valve to protect the system from over pressure as well, there is more to it but that's the basic idea.

At this point a warning......pressure oil in a fine feathery spray will penetrate the skin and may cause blood poisoning ,or fibrous growth in the affected area......oil penetration is no joke,and if it happens ,you are in deep s***t....so be sensible.

I have repurposed a lot of these types of units.
Pull the pump, clean out the tank and pump strainer, new fluid.
Determine the pump model # and specs before putting it back in.

Seems most of these are set up for 1500psi or less, so you may have to change the pump if you want more pressure.

I have gotten where I hold out for hydraulic units without the integral motor/pump.
The motors have frequently have oddball shafts, the pump specs are hard to find, flimsy plastic intake lines, internal non adjustable pressure relief, other pumps won't bolt up etc..

I like the ones with the motor having a regular C faced mount, lovejoy connection and run of the mill 2 bolt NFPA standardized pump mount.
Far easier to mix and match scrapyard scores.

john.k said:

At this point a warning......pressure oil in a fine feathery spray will penetrate the skin and may cause blood poisoning ,or fibrous growth in the affected area......oil penetration is no joke,and if it happens ,you are in deep s***t....so be sensible.

Click to expand...

No kidding! I spent 10min looking that up once, and gave me a whole new respect for hydraulic safety. Sadly seems like the type of injury that 9 out of 10 people probably brush off as nothing to worry about until it is too late, and parts needs removed...

For symlicity I would use a manual controled valve

Peter

Thank you everyone very much for the information. John thank you for the warning, it is duly noted and will be taken seriously. I’m having the motor rebuilt today by a friend who does that for a living and will get it back tomorrow. I’ll post back once I get the motor reinstalled as I’m sure I’ll still have a question or two lol

I knew a truck driver who put the palm of his hand over a leak in a hose for a truck crane ....fluid penetrated his hand ,and basically turned the hand into something akin to a football....Once the oil penetrates the tissues ,its there for good as its such finely dispersed globules.....He didnt get bloodpoisoning ,just made the hand fibrous and stiff,even after some of the oil was removed.....The feathery spray seems harmless,so light it couldnt even wet with oil,but the oil dripping down shows the leak is considersable.

johfoster said:

No kidding! I spent 10min looking that up once, and gave me a whole new respect for hydraulic safety. Sadly seems like the type of injury that 9 out of 10 people probably brush off as nothing to worry about until it is too late, and parts needs removed...

Click to expand...

That's only if you're lucky. I was on a job last February where a man was killed when a hose broke. Simplex jacks, total capacity 500 tons, hose connecting them broke. 24 year old father of two dead in 2 1/2 hours. This was in a mine with EMTs on site. He didn't last long enough to get to a big hospital, not that it would have helped. This shit's real.