PTO Pump driven with Jackshaft

[N8ghz]

Hello. I am trying to drive a Prince PTO pump (540rpm-21gpm), via a jackshaft off of a 65hp Wisconsin V465D Engine. I acquired this pump mainly for it's GPM for speed on a log-splitter/mini firewood processor I am building.
I so far have built a pulley drive using (4) 3v belts from the crankshaft to a 10.6" jackshaft sheave. The ratio is 3.03:1 which should be about 528 PTO @ 1600 engine or 594 PTO @ 1800 engine.

The problem is getting pressure. Belts squeel badly and it don't look like I will be able to get over 1100 psi no matter how tight I draw the belts. I do have a gauge on a test valve to the splitter cyl (4").

I am now going to change the jackshaft to chain....RC80.....13 into 38 teeth.

According to Prince specs, even 1500 psi will require 23.8 hp, while getting to 2000 psi needs 32.1.

I may make the 23.8 with the RC80 chain if I stay under 1100 RPM, but HP drops off rapidly above that with a 13 tooth driver.

I have (10) 3v steps on the crank pulley now, but even using all of them for belts seems futile.

Any ideas?....

Maybe I should forget using this pump? or maybe move to a 5" cylinder and
live with the lower PSI....the remaining hydraulic functions do not need this GPM or PSI.

 

[J_J]

SPECIFICATIONS
9.9 Cu. In. displ.
2,250 PSI max.
1,000 RPM input max.
Max output @ 1,000 RPM input: 40 GPM @ 2,000 PSI & 58.8 Hp input
Max output @ 540 RPM input: 21 GPM @ 2,000 PSI & 32.1 Hp input

You have to keep the rpm at max, for the figures quoted for the pump.

Is this a new pump? The pressure doesn't seem right. How did you set the system to measure the pressure.

Did you max out the cyl for the pressure reading?

What is the relief setting on the valve?

You should be able to run that pump with that
engine.

In order to get the volume and pressure, you need to change the ratios and use max engine rpm.

You are simply running out of HP at lower engine rpm. In the specs, you need 540 to get the 21 GPM's, but you should reduce the 3600 engine rpm down to the 540 or 1000 PTO rpm.

Your pump doesn't like the ratios, or the rpms.

Your highest pressure will be determined by the resistance to the fluid, and that is usually achieved
by holding the lever on the valve to full fwd or rev.

The relief valve will activate when doing this, now read the system pressure.

If you can't get the specified pressure, that means that the pump may be worn, or the relief on the valve is not set correctly.

Rpm's on the pump will dictate GPM's.

Using full HP on the engine, and a good pump, you should see 21 GPM at 540 rpm, and 40 GPM's at 1000 PTO speed.

Do you have a good return filter in the system?

What kind of valve are you using, and can it take the 21 and 40 GPM's?

You will have some fast times on the cyl.

For 1000 PTO rpm, you need a 3.6 ratio, and at 540 PTO rpm, you need a 6.66 ratio.

 

[N8ghz]

The pump is almost new....the problem is driving it.
(4) 3v5300's actually STOP at near 1100 psi with cylinder at end of stroke.
The D05 Vickers valve (open-center) is on a Damon subplate which has a max-2000psi relief in it.

When I said HP drops off....i meant the capability of the belts or even a chain (RC80 single) drops off...not the engine. The engine has plenty of HP....40 some at 1600. The belts smoke way before that.

I will try the chain.
The chain should deliver 25hp up to about 1200 rpm....then it looses capability.
The pump needs 23 for 1500 PSI and 32 for 2000 PSI.
The problem is delivering those Hp's to the pump via a jackshaft.

I guess I could use a truck-rear differential with a 3.0 ratio directly driven off the Wisonsin crank via coupling if the RC80 can't do it?

Sorry for confusion on the HP

 

[oldnslo]

Are you putting side load on the pump shaft? If yes you might to check to see that this pump is rated for side loads. Some are and some aren't.

Roy

 

[J_J]

Where are you getting the specs for the pressure. A pump is rated for the max pressure it can develop safely. If the pump manufacturer says it can develop 2000 psi, then that is what the pump will try to do, at any speed.

The specs for that pump is in post #2

The HP needed to run that pump is based on pressure and GPM's.

So from 1 rpm up to the max driven rpm, it is putting out potential pressure. That pressure is developed by the resistance to the flow. If you should happen to block off all pressure from the pump, the pressure will develop to 2000 psi or above, the pump , hose, other parts will probably self destruct.

If you use a valve to control the flow, and extend the cyl to max, the valve PRV will provide some pressure relief.

 

[Leejohn]

This is how I hooked mine up. Its right at 3 to 1 and my pump did have a side load that was somewher between 8 and 12 oclock. I made a chain adjuster and you might be able to see it, its a bolt that moves the pump.

 

[J_J]

About the only real way to measure the pressure and flow , is with a pressure gage and flow meter.

If you can only get 1100 or 1200 psi, then something is wrong. Pump is not working to specs, valve PRV set to 1100 psi, cyl leaking fluid internally.

If your pump can not develop the pressure, you can not measure and set the PRV.

Where is your hyd gage installed?

 

[J_J]

You mentioned subplates, are you using solenoid valves for the control, and if so, how do you have the cyl's timed to extend and return?

 

[N8ghz]

On the Q about side-loading:

No more than if it was on a PTO on a tractor. The Jackshaft is supported by 2 flange bearings on each side of the sheave. The PTO shaft simply sticks out with the pump slid on it, and then I have the outrigger to hold pump from trying to rotate.....same as if on a tractor.

The sheave base,bearings,etc are adjustable for steering & tensioning the belts (4).

On JJ's points:

The pump is a Prince HC-PTO-1A. The data I am going by is from Prince's data sheet. The pump is for 540 PTO RPM only (allowable over speed of 10%).

The one you mention is the Rear-ported is the HC-P-K11, which is not what I have.

Here are Princes Specs directly from their sheets:
HC-PTO-1A or HC-PTO-1AC (difference being Alum or Cast-Iron Center section)

540 RPM
8.4HP for 500 psi 21.4 gpm
16.1HP for 1000 psi 21.0 gpm
23.8HP for 1500 psi 21.0 gpm
32.1HP for 2000 psi 21.0 gpm

What you are not getting is that the 4 belts CANNOT deliver enough HP for the pump to put out over ~1000 psi....they slip.

I can run the engine to 1800 RPM as long as the GPM is going thru an open-center valve. But if I run the cylinder to either extreme in or out, I never get the relief to relieve (it IS a 2000 psi relief). The reason is not the pump. The pump STOPS because the belts are slipping/burning-up....kabish?

This occurs with gauge showing around 1100 psi while cylinder is fully extended or retracted or against a log,etc.

It's sorta like the irresistable force vs. the immovable object. The belts cannot deliver 23 or 32 HP and actually from some belt charts, I am surprised that they are delivering the HP to get to ~1000 psi.

 

[N8ghz]

The valve is a Vickers D05 series open-center...all ports. It is good for 25GPM.
The valve is on a subplate that has a cartridge Relief in it. It is adjustable to 2000 psi. This subplate has a P & T on both ends, just like a manifold. The extra P&T's had SAE plugs, but I put a gauge on the P. The other P goes to the pump. One T is plugged and one goes to the Tank.

Timing the cylinders?.....no idea what that means.
You mean with a stop-watch?

I can calculate speed OUT and speed in if need-be. But it is plenty fast both ways. That is not the problem.

 

[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?