Hydraulic Pump Noise... but not always.

[RDSmith]

Once again, please let me thank everyone for their input.

In this case however the blade speed is directly proportional to the diesel engine speed and that can't be changed at random. There is something mechanical (cylinder activated) that moves the blade away from the log and idles the engine during the carriage return. According to another mill owner something can be added to the single valve circuit that controls the motor for carriage travel speed to vary travel speed. I'm worn out just reading that sentence. "flow controller" ?

Just realized I've been misspelling "circuit" in previous posts. Dang.

I now see I can also look for a part number on the inlet plate to find out about the relief valve. Assuming nothing has been changed.
Thanks again for the reference manual for SV valves oldnslo.

 

[KWentling]

I believe Oldnslo is giving you great advice.

 

[RDSmith]

Hey, I'll take any advice and welcome it. Please someone try to explain to me the difference between a relief valve between the pump and say a stacked spool valve and the relief valve that is a part of the stacked spool valve (maybe wrong term)? They don't do the exact same thing?

 

[K5lwq]

Hey, I'll take any advice and welcome it. Please someone try to explain to me the difference between a relief valve between the pump and say a stacked spool valve and the relief valve that is a part of the stacked spool valve (maybe wrong term)? They don't do the exact same thing?

They do the same thing. Relief valves are there to protect the pump or limit the pressure for a certain action. But when valves are in series, the pressure relief on the first valve will be the maximum pressure for the rest of the valves.

Some systems will use a flow divider that will allow fluid from one pump to be split. This is usually adjustable to the amount of flow you need for one valve stack and allows another valve to use the remaining flow at the same time.

In this example, you may would want a pressure relief before the divider that sets maximum pressure for the system. Then each valve could be set to different pressures depending on needs. But if both valves are used at the same time, the main relief would protect the pump.

Hope that makes sense and does not confuse you more. Lol

 

[oldnslo]

K5,
great explanation on relief valves and there purpose in a system.

RD,
If the blade is mechanically driven by the engine do you have to change diesel engine speed to change blade speed or is there different pulley sizes or something used to vary the blade speed? If adjusted by changing the engine speed this will have an equal change on available pump flow presuming the pump is driven by the same engine.

example: If engine at 2000 RPM you get 10 GPM flow, reduce engine to 1800 RPM could give you 8 GPM flow.

On the hydraulic side operation. Do other functions operate while the carriage is moving during sawing?

It appears that most if not all of the valves are mechanically operated so I presume you will be pushing and pulling levers to control functions. Will most of these be an attempt at controlled speed movement or more of a grab and go type operation where you just pull the lever and function moves?

I am just trying to get a feel for how you want this mill to operate so that we - means you can start figuring out the best way to get the mill operating close to your expectations.

 

[Sidney71]

Wondering if anyone has ever had this issue... the hydraulic pump sounds just fine when either a cylinder or hydraulic motor is activated but when neither is activated the pump makes a bad noise and the suction hose vibrates? I'm of course baffled. Any ideas?

Sounds like you have a closed system when you are not using your hydraulics. There should be a bypass that will allow fluid to circulate .

 

[KWentling]

Is this a Woodland MFG saw? Found a couple of Youtube videos that look a lot like it. The one had the Kubota engine running only the blade via a hydraulic motor and a 8 HP Honda running all the other other hydraulic functions. That did appear to be gear pump on the Honda.

 

[greenerdreams]

there is some good troubleshooting going on here but have you started simple and just opened the reservoir after running it to see if the fluid is getting aerated(possible via a suction leak)?

 

[RDSmith]

Please allow me to not include which of you made a suggestion or comment recently. I'm having enough trouble recalling.

Yes, Woodland that went out of business years ago. Not the present Woodland that manufactures mills.

Only one controlled function needed at one time. The engine drives the blade via belts and pulleys. Blade wheel rpm is one forth the rpm of the engine.

There is a mechanical lever that increases rpm when a cylinder moves the blade into a more vertical position for cutting. When the blade is moved away from the log during carriage return the rpms go to idle.

There is some air in the fluid but I'm wondering if that was because all the fittings were tightened when I first used used the hydraulics. Lots of new empty hoses.

Supplier is checking to see if valves can be changed to open circuit.
oldnslo pointed out the issue of the "CC" plugs.

I have to ask Prince support one more question. They gave me a part number but I'm not convinced yet they understood what I was looking for.

Support says option 2 will fit my bill. They are probably right but I'd sure appreciate other's opinions. Remember, if possible I want to take the outlet hose for the first valve stack and connect it to the inlet of the second valve stack making all open circuit.

Now I see oldnslo agrees with support and the part number... sorry about that oldnslo. I'm not clear though if you think it will be needed on both valve stacks. Or which one.

 

[oldnslo]

RD,
I believe that Power beyond fitting would work in either valve stack. You will have to convert both valve stacks to open center and or power beyond. First stack will require power beyond fitting to feed second valve stack. Does the second valve stack need to feed anything else? If yes you will need a power beyond fitting for second valve stack. If no you will need to remove the CC plug and either cut the nose off that CC plug or obtain a #10 SAE plug to install in that hole. By removing the CC plug you have now connected the power beyond flow path to the tank flow path in the valve which makes it an open center valve without power beyond.

NOTE: You will still require a the separate tank line on the power beyond valve stack so do NOT remove that.