Jerky project cylinder action

[J_J]

I am assuming the two spool valve is used for the motors. It depends on the lever position as to how much fluid is going to the motors.

The fluid not gong to the motors is passing through the first valve and flows from the PB port to the cyl valve.

So the available fluid for the ram/cyl is the left over fluid not used by the motors.

If the hyd motors are not using the fluid, then the full pump flow is going to the cyl valve.

If you then move the lever to operate the ram, it will move very fast and then the relief will try and relieve. It may not be able to relieve 16 GPM flow, and the engine will start to complain.

When you move the lever a little, some fluid is going to a work port and works the cyl at some pressure based on resistance or load. The rest of the flow is passing on through the valve to tank.

I think if you split or divide the flow, you can manage the motors and the cyl flow.

For instance, if the pump flow were to go into a FIXED FLOW PRIORITY DIVIDER WITH PRIORITY PRESSURE RELIEF with a 3/30 split as posted above, the cyl circuit would always get 3 GPM, and the hyd motors would get the remainder of the pump flow.

Assuming a 16 GPM flow.

3 GPM goes to cyl valve.

13 GPM goes to the hyd motors.

The OUT ports from both valves are teed together and goes to tank.

You could then remove the PB adapter and plug the PB port.

If you have a 16 GPM pump at 1500 psi, it will take about 16 HP to do the job.

If that pump is a 1.8 cu in displacement, and turning at 3600 rpm, then it can pump about 28 GPM.

Some things are not adding up.

 

[yarg]

JJ
I am following your info pretty well.
The stall situation you relate is what I had come to understand:
All excess flow has to go through the relief valve and in a shock thus stalling the engine which is under powered but still enough for the drilling and hoist needs.
The ram needs almost no flow but gets the full flow though the power beyond fitting.
Is there proportioning valve designed for splitting the flow as you speak of?
My estimated fix is just an idea to date.

 

[wdchyd]

Yes correct, I have not had great sucess with counterbalance valves. A lot of chattering when cold. The adjustable flow control has been the best for me in this case. We also build a "fuse" wich is just a orfice to control cyls in case of a line failure. CJ

velocity fuse..??

Do work for a manufacturer or distributor..?? or a custom thing

 

[J_J]

yarg: You said

All excess flow has to go through the relief valve and in a shock thus stalling the engine which is under powered but still enough for the drilling and hoist needs.


No, not exactly.

No matter what the flow in GPM, the lever only lets fluid in to the work ports based on lever lposition.

Say you had a 10 GPM flow, and you wanted to move the cyl slow.

The lever moves the spool so fluid is flowing to the work port, a small amount, say about 3 GPM of fluid flows in to the cyl and the cyl starts to move. When the 3 GPM has extended the cyl, the 3 GPM flow begins to be relieved, and goes to tank, and the rest of the pump flow is passed through the valve, not the relief.

A condition when all pump fluid try's to flow through the relief valve is in a deadhead situation where the fluid has no path to tank except the relief valve. If the relief valve can not handle the flow, the engine may stall or something may burst, be it a hose, valve , fitting.

Are the hyd motors running part time, or full time?

When do you use the ram? In conjunction with a motor running, or both motors running.

Do you have to hold the lever to run the motors? Do you use full lever to run the motors.

If they are running full time, then there is probably not enough fluid for the ram The used fluid from the hyd motors will flow through the OUT port of the two spool valve to tank.

 

[J_J]

yarg,

Can you give us an operating scenario in drilling , from start to finish.

Such as

setup rig

connect water

load pipe stem with drill head using ram

start water

start hyd motor to turn drill

start down pressure

etc

 

[yarg]

JJ,
Here are the answers to you questions:
Normal use the motors are not used during ram use therefore all the flow goes to the ram spool.
There is between 10 and 15 gpm of flow at engine speed while not drilling.
The ram takes at most .3 gal to fill so in reality the ram spool has to divert nearly all the rest to the relief valve then on to the return line.
I have to hold the levers to run the motors for safety purposes.
The motors only run when spool valves pulled.

From what I have determined to this point:
I have to fill the ram at an altra slow pace to eliminate the speed and thus jerky motion.
When filling the ram, 99.9% of the fluid has to go through the releif valve which has a pre assure setting that is so hi that it stalls the engine.
Possible solution is the meter the cram flow with a needle valve and get a lower pressuer relief cartridge into the spool valve in hopes that the lower pressuer will not stall the engine?
Gray

 

[yarg]

Set unit

Start engine and raise mast using ram.

Lift head up to drill pipe mounting height using hoist motor.

Install drill pipe.

Begin ti drill using drill motor and slowly use hoist motor to lower drill head, both motors on occasion may be used.

When drill pipe is at it's end use, using drill motor and hoist motor, repeat the sequence until well is drilled.

After exctarcting the drill pipe , lower mast with ram.

That is about it?

 

[J_J]

Using the ram, if you only apply a little lever, most of the pump flow is going directly to tank.

If you keep applying fluid to the ram cyl, when the cyl is full, the small amount of flow is now forced through the relief valve.

All pump flow does NOT go through the relief valve. Just the flow the cyl can not use after it is full.

Pressure is only developed when the ram is working a load, and may not develop very much pressure.

A pressure gage will keep you informed.

 

[yarg]

JJ,
You found me looking for input on the project posts.
Yes, I ask many questions of many to discover things.
I ran out of gas last night while trying the two options for ram flow. One, the very careful levering of the valve keeping the bulk of the flow bypassing the relief and two running the motor while doing the ram thereby bypassing most of the fluid.
I will try today?
It is five miles away so it is not like just stepping out to try.
Thanks for hanging in this with me.

 

[yarg]

JJ,
Bad weather stopped my test plan but I checked the pump and motor specs.
Pump: max psi 2300 at max gpm of 24 at 3600 rpm. Rated 16 gpm at 2200 rpm.
Motors: max psi 1550 and 23 gpm at 181 rpm. Continuous is 1450 psi and 16 gpm at 150 rpm.
The engine ISVs bit under powered like about 25% but good for one motor at a time for full output?
Gray