Valve screwing with my head

[Tx Jim]

I've operated farm equipment orbit motors on augers on play/Jane hyd control valves many times with no ill affects. I see no need for the special valve or plumbing. Maybe the industrial application is different.

 

[aczlan]

I've operated farm equipment orbit motors on augers on play/Jane hyd control valves many times with no ill affects. I see no need for the special valve or plumbing. Maybe the industrial application is different.

Its for something that has a lot of inertia (like a bush hog) to let it spin down without blowing a hydraulic line.

Aaron Z

 

[muddstopper]

Jim, Azcan, this valve will be used to control a pair of cylinders on my firewood processor, that I am building. Its previous use is completely not related to this function. Is intended use is to run a hydraulic motor used to run a axle on a 63000lb piece of equipment. The equipment used variable displacement pumps, load sensing, and a bunch of other stuff I dont understand. With variable pumps, its common to use closed center valves, and in this case charge pumps that have a standby pressure of about 600psi to tell the variable pumps to build pressure when the charge pressure drops. What I am trying to do before I invest a lot of money, is determine if this particular valve can be used to control my cylinders while using a positive displacement pump. Even if the valve can be converted to open center use instead of closed center, there is still the part about spool configuration. Since this valve was intended to control a hydraulic motor, it would be possible that fluid could flow from the A work Port, to the B work port to allow the motor to coast in neutral. If this is the case a hydraulic cylinder could retract or extend under load, without the valve spool being shifted. A cylinder in extend position could fall when the valve was placed in center. A cylinder spool valve would have oil flow blocked between the A/B work ports while in the center position. This could act as a brake for a hydrauilc motor, preventing it from float in neutral, or provide a hydraulic lock preventing a cylinder from falling if left in an up position. There is also the option that this valve could have regen capabilities, allowing the oil from one side of the motor or cyl to be returned to the other side to provide simulated more oil flow, but I dont think that option is machined in this particular valve. even buying fittings to test this valve is expensive since the IN port is #20jic and the Out port is #24jic, so I am trying to find out all I can before building and installing the processor this valve it is intended to operate. I intend to pump 60gpm of oil thru this valve.

 

[Tx Jim]

Its for something that has a lot of inertia (like a bush hog) to let it spin down without blowing a hydraulic line.

Aaron Z

OK that makes sense. But to just state an orbit motor requires a special hyd valve isn't exactly a true statement unless one adds an orbit motor with a lot of inertia.

 

[J_J]

Since the valve has PB installed, the flow path is IN port to PB port in neutral.

When you shift the lever to run the motor, you are diverting some or all of the pump flow to a work port.

The flow from the motor is from one of the work ports to the OUT port.

If the spools is a motor spool, the motor will coast in neutral.

If you only use some of the flow for the motor, the rest of the flow passes through the valve PB port.

Will your motor run full speed all the time. Do you have any control of the speed other than the lever on the valve? The lever is probably spring center.

The best valve to control motor speed is something like this.

3/4 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS175-30

 

[muddstopper]

JJ, I dont think you read some of the post. I intend to use the valve to control a pair of cyl's, mounted side by side. I also will have a oil flow of 60gpm. Also, in order fo the motor, or in this instance cyl's, to coast, there would have to be a clear path for oil flow from A port, to cyl/motor, to b port, to tank, with valve in center position. Is this not correct. This valve has the a/b ports blocked to tank when centered, so I am assuming it is cyl spool and not a motor spool.

 

[aczlan]

JJ, I dont think you read some of the post. I intend to use the valve to control a pair of cyl's, mounted side by side. I also will have a oil flow of 60gpm. Also, in order fo the motor, or in this instance cyl's, to coast, there would have to be a clear path for oil flow from A port, to cyl/motor, to b port, to tank, with valve in center position. Is this not correct. This valve has the a/b ports blocked to tank when centered, so I am assuming it is cyl spool and not a motor spool.

Actually, a motor spool has ports a and b connected together when centered.

Aaron Z

 

[muddstopper]

Actually, a motor spool has ports a and b connected together when centered.

Aaron Z

correct, this allows oil to flow, circulate. If, as in the case of this valve, oil is blocked and cant flow between a/b, then this isnt a motor spool. Or thats the way I am thinking this is supposed to work

 

[J_J]

With 60 GPM running through this valve,you are going to have some really fast cyl.

 

[muddstopper]

twin cylinders, 4.5x2.5x30in stroke, so not as fast as one would think. Actual cycle times probably around 7 sec. It will be a 50ton splitter with a 12way adjustable box wedge. Ideal wood size would be 20-24in dia for minimal resplits. Box wedge will accept up to 30in max dia. I have a 27in .404 bar/chain, I bought when I first started this project. I do plan on up sizing the bar/chain after all the testing is complete. I think I have this valve sorted out as to what it is and how it needs to be plumbed for my use. My next problem is trying to figure out how to use the power beyond to supply 30gpm for my saw motor.