hydraulic pump

[godewey]

Hello,

This is my first post. I hope I am in the correct forum.
I have an old homemade woodsplitter. It has a 1972 briggs engine and
a williams machine tool box system, which is a resevoir with the pump
on the inside. I am looking to put on a new engine and a bigger pump.
Is it possible to change out the pump in this resevoir or will I have to
also get a new resevoir? I also have a 48" cylinder on this. It is very slow.
If I want to speed this up Is it better to get the bigger engine and pump
or smaller enginge, smaller pump and smaller cylinder?

Thank you
tim

 

[Iplayfarmer]

I don't know anything about replacing the pump in your system, but I can comment on speeding the splitter up. Go with a bigger engine and pump using the same cylinder. A smaller cylinder will have less force and may not do what you need it to.

 

[godewey]

That's something I didn't even think about. What would you say
16 hp engine, 22gpm pump big enough or do I not need that big of an engine ?

 

[J_J]

Comparison of a 48 in cyl and a 24 in cyl.

You could split two 24 in logs during a complete cycle.

22 GPM 48 in, 4 in cyl, 2 in shaft,

Extend = 7.2 sec

22 GPM = 24 in, 4 in cyl, 2 in shaft

Extend = 3.56sec

Retract will be faster.

The two stage will switch as necessary at the set cross over, usually around 400 to 600 psi.

The 7 GPM and high pressure times will be slower.

What yo will have is a combination of Extend and Retract cycle times.

 

[Iplayfarmer]

That's something I didn't even think about. What would you say
16 hp engine, 22gpm pump big enough or do I not need that big of an engine ?

16hp seems like plenty of engine for a log splitter. What do you have now?

 

[godewey]

Like I said this engine is old. It shows its age. I had to remove a lot of
crud just to find out a model and a year. I really don't know
what it is. My guess is a 10hp or a little smaller.I bought it a few years ago for $200. This thing is a beast. not much to look at but will split everything I put on it. Do you know off hand what the minimum hp is required for a 22gpm pump ?

 

[J_J]

Is the 22 GPM pump a single stage or two stage?

A 22 GPM single stage pump at 3000 psi will take about 45 HP.

Two stage hyd pump will take about 7 HP for 22 GPM at low pressure, and 14 HP for 7 gal at 3000..

 

[Iplayfarmer]

Do you know off hand what the minimum hp is required for a 22gpm pump ?

I came up with 25 hp based on the equation HP = GPM X PSI / 1714 (Wikipedia Horsepower Article). I used 2,000 PSI for the pressure. Higher pressure requires higher horsepower. 3500 PSI would require 45 hp.

Of course none of these numbers account for any transmission losses.

 

[J_J]

This rule of thumb is for the HP needed to drive a pump as in a belt and pulley situation. Using a direct drive, I don't think there would be any loses .

Pumping = 1 Hp = 1 GPM x 1500 Psi
(linear relationship i.e. 2 GPM @ 1500 Psi = 2 Hp)

The formula below is used to compute the HP the pump will develop with no loss.

Hp to drive hydraulic pump = Psi x GPM / 1714

 

[godewey]

It looks like a 14 hp motor with 22 gpm pump and accessories will be about
$1000. A 9hp motor with 16 gpm pump for about $800. This of course does
not count the new resevoir and probably new hoses. So I guess it comes down to how fast do i want it and how much do I want to spend.
Either way i decide I may be back for some help putting this thing together.
Thanks for all the information.