PTO Pump driven with Jackshaft

[N8ghz]

Leejohn, yours look like you are speed increasing from the PTO.
I am Speed reducing from an engine to a jackshaft-mounted PTO shaft.
This is on a stationary engine, not a tractor.

 

[J_J]

I understand the belt capability thing. You diffidently have to over come that aspect.

What you are not understanding, is that the pump is developing available pressure, at any rpm, so run the engine at 1/4 rpm, and you have some volume with pressure if the lever is in the extend position.

If you are only pushing 8 GPM through the system, the HP necessary to do this would be 11 HP. So, if everything is good and tight, the cyl at full extend should cause the pump to develop the 2000 psi. If not, that means that you are not blocking the fluid sufficiently, the 2000 psi will not develop.

What is the relief pressure in the DO5 subplate?

 

[N8ghz]

This engine is not a Briggs-& Stratton, it is a Wisconsin V465D 4-cylinder 177cu.in 65.9HP @ 3000 RPM, 41.6HP @ 1600 RPM, 47.5HP @ 1800 RPM,etc.

My ratio of choice with the belts is 3.03:1 or 528 Jackshaft/Pump @ 1600 engine. At 1800 RPM engine, pump would be 594 rpm which is the allowable overspeed on the pump according to Prince.

My plan was to keep engine RPM as low as possible to conserve fuel (I am cheap, ha-ha), being that I have plenty of horsepower available.

The Prince pump at 2000 psi needs ~32 HP and is still capable of 21 GPM.

That is what I am after and if I can get it @ 1200 RPM on the Wisconsin....all the better.

The remaining hydraulics on this build do not require all of this PSI and/or GPM.
Biggest demand for GPM on those items is the saw, which I want to run at it's full rated power/speed of 8 GPM @ 2000 PSI.

I will post some pictures as this project progresses beyond the "burning-up belts" stage.

 

[N8ghz]

JJ not to be arguementative, I agree with you to a point on volume/pressure/restriction/relief setting,etc....however if the pump STOPS turning because the belts burnt off at the drive sheave @ 1000 PSI....that's the end of it...there will be no more GPM's or PSI's till we get the pump turning again.

 

[N8ghz]

I understand the belt capability thing. You diffidently have to over come that aspect.

What you are not understanding, is that the pump is developing available pressure, at any rpm, so run the engine at 1/4 rpm, and you have some volume with pressure if the lever is in the extend position.

If you are only pushing 8 GPM through the system, the HP necessary to do this would be 11 HP. So, if everything is good and tight, the cyl at full extend should cause the pump to develop the 2000 psi. If not, that means that you are not blocking the fluid sufficiently, the 2000 psi will not develop.

What is the relief pressure in the DO5 subplate?

Roger....IF it was an 8GPM pump. It is a 21 GPM pump. And being a gear-pump, it is a positive-displacement pump. Remember your example of 1 RPM?

The problem is trying to move 21 GPM. As you & I can see from the Prince chart, as desired PSI goes up, the HP to move 21 GPM and raise the pressure goes up. A little efficiency of GPM is lost as pressure increases due to leakage from the pressure increase, but it stays around 21.0 clear up to 2000 PSI.

If I had used an 8GPM pump, I am sure my belt setup would make 2000 PSI.....what do you think about that?

 

[J_J]

N8ghz

[ If I had used an 8GPM pump, I am sure my belt setup would make 2000 PSI.....what do you think about that? ]

You have an 8 GPM pump. The pump will pump and GPM from 0 to 21 GPM. So run the engine down low.


I am sorry, but the volume or fluid in GPM's on a gear pump is directly related to the rpm of the shaft. The pump may be capable of pumping 21 GPM's, but that is at 540 PTO rpm.

Put the end of the hose in a bucket and see for your self.

 

[J_J]

I am assuming you have this, if not here it is.

http://www.princehyd.com/Portals/0/products/pumps/PtoManual.pdf

I don't think I can add anything further. I am out of ideas.

 

[Leejohn]

I forgot about you going down in RPM's when I posted. With the way your doing is just like hooking to PTO shaft and it well work and should work good. Use the chain as you want or look into gear box. Forget the side load as Roy and I were talking about. My pump is just std. Hyl. pump and it has side load specs.
If you do it with chain, it well not cost a lot and if it doesn't then regroup.
Go for it!!!!

 

[mmurphy]

Possibly guage has been dropped not giving true psi?
Belts also need to make a certain amount of contact around pulleys. Is it possible this may need reviewed?
It does sound strange to me that the 4 belts are not running it any higher then 1100 psi before burning.

 

[N8ghz]

I guess I should have aimed this Q into a 'power transmission' question area?

Obvoiusly in my selection of 3V belts, I didn't research their limits enough.

I now have a PDF from Martin (Sheave,Sprocket co.).

The reason I selected 3V's in the first place, is because the engine came with a 10 groove sheave that is all 3V's. The engine is off of a 4' concrete saw. I figured if 10 belts were sufficient to drive a 4' concrete blade, then 4 may drive this pump? Apparently I was wrong?

I calc'ed my ratio to be 3.03:1 reduction.

The closest example in Martin's literature to this is as follows:

2.93 ratio using 3.65" driver and a 10.6" driven.
(that is close to mine, as I am using the 10.6" driven & driver is close to 3.65)

here is where I fail with this sheave combo:
The chart for this ratio combo starts at 3500 RPM
@3500 rpm 7.46 HP per belt
@1750 rpm 4.15 HP per belt
@1160 rpm 2.88 HP per belt
@ 870 rpm 2.23 HP per belt

These figures are for an electric motor and 3VX belts...I think the VX is better than the V's, but the difference is still anemic for 4 of them.
I am running the 3V's, not the 3VX's.


So it looks to me like, at say.?...1160 engine rpm, I can deliver (2.88x4) HP, or 11.52 HP.

This tells me alot.

Even at 1750 the 4 can only deliver (4.15x4) HP or 16.6 HP.

I never did intend to run the engine to 3000 rpm, I wanted to run it similarly to if it is a tractor PTO....being able to idle down or rev to 540-600 PTO....depending on how fast I felt like working.


No wonder I can't get the pump to make more than 1100 PSI.

I will remake my jackshaft tensioner/mount and try RC80 Chain in a single chain.

If that is a problem, I am now thinking of adapting a final drive setup as used on the high-performance belt-sprocket Harley's or other motorcycles?