PTO Hydraulic Pump

[jcurtisB78]

I'm in the process of completing a backhoe for my Kubota tractor and I have a question regarding a hydraulic pump. At first I considered purchasing a PRINCE HC-PTO-2A but after reviewing the dimensions it looks like it will interfere with the structure around my pto. One way it hits the safety shroud the other the drawbar pin, in addition the side ports would make it difficult to attach hoses. I looked around the Surplus Center site and found two possible alternatives:

First, a 3.179 cu in PRINCE HYD PUMP SP25A52D9H2L with a 1-3/8 6T TO 7/8 BORE SNAP HITCH ADAPTER

Second a 4.46 FENNER HYD PUMP with a 1-3/8 6T TO 1 BORE SNAP HITCH ADAPTER


With the shaft attached, I would avoid clearance problems and using the formula, RPM = 231 x GPM / motor displacement I should get around 7.5 and 10.5 gpm respectively running of my 540 rpm pto. I would also save a few bucks as a bonus :thumbsup:. Are these good options or am I all wet?

Thanks in advance

 

[jfay]

I think you would be better off with a pto hydraulic pump than making up your own. The pto pumps are pretty standard and designed to fit most tractors. It has to contact your drawbar or something to keep it from spinning. Put 90 degree fittings on the ports and you should be fine.

 

[jcurtisB78]

Thanks for the reply, but the width of the pump is around 6 3/8" and the safety shroud is only 7" so even with 90's it is still a no-go.

 

[J_J]

You already have 9.5 GPM total hyd flow, with some of that for steering.

http://www.kubotatractor.org/kubota-b7800-specs.pdf

Do you have 2500 rpm mid PTO?

Use what ever it takes to get the required volume. You probably have more pressure with these pumps, and if you have different tractor PTO rpm, you can get more GPM.

At 2500 psi, it will take about 12 HP to run a 3 cu in pump at 540. At 1000 PTO rpm, you can pump 13 GPM's, and that will take about 22 HP.

You only have 22 PTO HP.

 

[jcurtisB78]

You already have 9.5 GPM total hyd flow, with some of that for steering.

I've gone back and forth about a million times between using the tractors hydraulics and a separate pto pump. I'm currently leaning toward the separate pump just because it seems like a more simple setup and by the time I get all the hoses and fittings made up to plumb into the tractor I'm close to the price of the pump.

Do you have 2500 rpm mid PTO?

Yes I do.

I'm looking to run the hoe at 2000 psi and 7 to 8 gpm so if I use PSI x GPM / 1714 I should be well within the capacity of my 22 hp pto, no?

 

[J_J]

Yes, that is correct.

Which BH valve did you select?

The least expensive and more functional would be this.

One hose from the PB outlet to the back with a QD.

Another hose with QD back to the 3pt.

If using the BH, just plug into these QD's.

When not using the BH, connect a short hose jumper connecting the two QD's at the back.

 

[jcurtisB78]

The bh valve is from Bailey's:
Chief Directional Control Valves (22 Series)

Forgive my ignorance, QD?

 

[jcurtisB78]

Doh! quick disconnects :ashamed:

 

[jcurtisB78]

One hose from the PB outlet to the back with a QD.

Another hose with QD back to the 3pt.

If using the BH, just plug into these QD's.

When not using the BH, connect a short hose jumper connecting the two QD's at the back.

Would I need an additional line to return to the reservoir?

The bh valve has three ports on it marked P,T, and N, with the N being plugged when I received it. I'm reading them as P for pressure, T return to the tank, and the N being the PB. I'm trying to confirm that with Bailey's but no luck so far.

Thanks again for your help

 

[J_J]

You can put air to the valve and confirm the ports by operating the levers, but that seems right.

Yes, the tank /return port has to go to tank/reservoir.