Hydraulics and heat

[roadhunter]

Duplicate

 

[roadhunter]

Info on the flow divider.
Webtec - Hydraulics - 2FV2V (Variable priority flow divider valve)

I'm thinking about adjusting it to see what happens. It appears to be on the max setting.

 

[Tx Jim]

If in fact the attachment is a closed center hyd system, the closed center relief will be on most of the time.

A true closed center control valve doesn't need a relief valve as pressure can only get as high as set by stroke control valve in hyd pump.

 

[Jabonee]

I don't 175 is to hot, I would ask the dealer. I wouldn't be to concerned unless it went over 200

I agree. Rule of thumb is 100 degrees above ambient temp.

 

[Tx Jim]

I agree. Rule of thumb is 100 degrees above ambient temp.

Ditto on 100° above ambient for hyd oil operating temp.

 

[seth350]

This isnt the best drawing, and AutoCAD crashed before I could save to a better format. Does this look like your machine?

View attachment Drawing1.pdf

 

[roadhunter]

This isnt the best drawing, and AutoCAD crashed before I could save to a better format. Does this look like your machine?

View attachment 447857

I believe it is. I'm not familiar with the symbol for the 3rd valve which also goes to a cylinder but I believe the plumbing layout is correct. I appreciate you taking the time to do that.

I am still trying to figure out what to do at this point. I'm considering adding a pto pump, tank and valve to the machine so it has it's own hydraulic system. That way I can get a valve with adjustable flow to hopefully prevent the heat issue since the flow divider that was installed did not have an effect. I tried adjusting the flow divider today with no noticeable difference in oil temp or machine performance. It was only 15 outside and oil was still close to 200 when running the machine with the farmall.

 

[the old grind]

Hmm. It's made to go on a tractor so I just assumed it was open center. I'll have to do some research on that one.

What J_J said. A CC valve properly plumbed into an OC circuit will have the system in bypass when that valve isn't being operated.

CC systems use an 'unloader' to manage flow at full pressure (a pilot operated valve that can 'dump' full flow back to tank when all system valves are 'closed').

IMO, neither an OC's relief valve, a flow divider, or both will necessarily accommodate full pump flow if the operating valves are mismatched. (eg: CC used in OC system) :2cents:

 

[Tx Jim]

CC systems use an 'unloader' to manage flow at full pressure (a pilot operated valve that can 'dump' full flow back to tank when all system valves are 'closed').

CC hyd systems that I'm familiar with(JD) have a stroke control valve that when set pressure(known as stand-by) is reached CC pump simply stops pumping oil IE there is no flow to "dump" back to tank

 

[the old grind]

CC hyd systems that I'm familiar with(JD) have a stroke control valve that when set pressure(known as stand-by) is reached CC pump simply stops pumping oil IE there is no flow to "dump" back to tank

OP has JCB IIRC, if it's the same as JD's setup. (btw, there's is plenty of non-vehicular application out there ..)

I would expect stroke-controlled pump/system to generate the least heat if valves/system are mixed up (no bypass) but I'd still want to be sure they're matched up right.

(Gets confusing if the JCB is OC vs CC ...)

 

[Tx Jim]

JD CC system with high pressure internal leak or when OC valve is installed can generate a lot of heat.

 

[the old grind]

Shootin from the hip, here:

I read back looking for details, and in post #20 the OP said his saw worked on the JCB as set up for OC. If JCB is thus, then I go back to the U/S 1/4" Tee esp w/out knowing where it's situated in any continuous flow path.

A possible restriction in the 'main' still seems troublesome (GPM cap ~50% of 3/8" fittings & existing lines). Are we trying to shove a steady (OC) ~8 gpm thru ~4 gpm bits, and generating heat and pressure by doing so? (IMO the flow divider is rendered ineffective if downstream of the tee, should have been helpful otherwise...)

Any 1/4" plumbing on the Farmall? Tee/gauge added for the peeler?

 

[TomNOh]

The flow divider is doing absolutely nothing to reduce your total flow as plumbed. 8gal/min comes out through 1 hose, 8gal/min returns through 1 hose. If the bypassed fluid was returned to tank via a separate hose, it might help some. As was stated above, you need to be sure that the tractor & machine are both either OC or CC systems. It will not work properly with mixed systems.

 

[muddstopper]

I cant add anything useful to this discussion except to comment on Tomnoh post. My first thoughts where also that the divider valve might not be plumbed correctly so I looked it up here, Webtec - Hydraulics - Downloads - Literature and it appears to be installed correctly. going off the numbers posted for the valve,2FV2V-, it appears it doesnot have a internal relief, but the next valve, RV2FV2V does have a relief. I can only guess the accuratecy of the numbers posted, but in the event the DV in question is in fact a RV2FV2V with internal relief, it could be possible that that relief is set to high and might need some adjustment. Also in the pdf file of the hydraulic circuit, that design doesnt make sense. No relief between pump and control valves, suggesting maybe a closed center system, but all control valves are open center, a relief valve on the return stroke of the last cyl circuit and the installation of a check valve on the return side after the relief. I dont understand the reasoning. I do realize tho that this is not the actual schematic of the machine in question.

 

[TomNOh]

I cant add anything useful to this discussion except to comment on Tomnoh post. My first thoughts where also that the divider valve might not be plumbed correctly so I looked it up here, Webtec - Hydraulics - Downloads - Literature and it appears to be installed correctly. going off the numbers posted for the valve,2FV2V-, it appears it doesnot have a internal relief, but the next valve, RV2FV2V does have a relief. I can only guess the accuratecy of the numbers posted, but in the event the DV in question is in fact a RV2FV2V with internal relief, it could be possible that that relief is set to high and might need some adjustment. Also in the pdf file of the hydraulic circuit, that design doesnt make sense. No relief between pump and control valves, suggesting maybe a closed center system, but all control valves are open center, a relief valve on the return stroke of the last cyl circuit and the installation of a check valve on the return side after the relief. I dont understand the reasoning. I do realize tho that this is not the actual schematic of the machine in question.

I agree, priority flow divider is plumbed as designed, but it is a PRIORITY flow divider valve, meant for another use, not for the intended use in this application. It is meant to assure hydraulic flow to circuit #1 regardless of what circuit #2 does. Circuit #2 gets the portion of flow that circuit #1 does not use. If that is ZERO, then circuit #2 gets ZERO flow. It does NOT just divide flow 50/50.

 

[roadhunter]

Thanks for the replies. I've been doing some research and a fella on heavy equipment forum was kind enough to give me the hydraulic system information.

 

[roadhunter]

I cant add anything useful to this discussion except to comment on Tomnoh post. My first thoughts where also that the divider valve might not be plumbed correctly so I looked it up here, Webtec - Hydraulics - Downloads - Literature and it appears to be installed correctly. going off the numbers posted for the valve,2FV2V-, it appears it doesnot have a internal relief, but the next valve, RV2FV2V does have a relief. I can only guess the accuratecy of the numbers posted, but in the event the DV in question is in fact a RV2FV2V with internal relief, it could be possible that that relief is set to high and might need some adjustment. Also in the pdf file of the hydraulic circuit, that design doesnt make sense. No relief between pump and control valves, suggesting maybe a closed center system, but all control valves are open center, a relief valve on the return stroke of the last cyl circuit and the installation of a check valve on the return side after the relief. I dont understand the reasoning. I do realize tho that this is not the actual schematic of the machine in question.

I believe there is a relief valve in the first circuit as the drive wheels can jam and the tractor does not big down as if a huge load is being applied. There is a dial toad just the wheel speed/flow so I assume it is built into that. Bottom right hand corner in the pic.


The relief valve on the top circuit is designed to make the pressure on the arm adjustable depending on the material being processed.

I believe the check valve is to prevent issues if the hydraulic flow on the tractor was accidentally switched. That was the first thing they had me remove when troubleshooting but it made no difference.

 

[roadhunter]

I agree, priority flow divider is plumbed as designed, but it is a PRIORITY flow divider valve, meant for another use, not for the intended use in this application. It is meant to assure hydraulic flow to circuit #1 regardless of what circuit #2 does. Circuit #2 gets the portion of flow that circuit #1 does not use. If that is ZERO, then circuit #2 gets ZERO flow. It does NOT just divide flow 50/50.

This makes sense. They had it adjusted to the max setting and I turned it down to just over half way but it did not make a difference in temp or machines performance.

 

[roadhunter]

The flow divider is doing absolutely nothing to reduce your total flow as plumbed. 8gal/min comes out through 1 hose, 8gal/min returns through 1 hose. If the bypassed fluid was returned to tank via a separate hose, it might help some. As was stated above, you need to be sure that the tractor & machine are both either OC or CC systems. It will not work properly with mixed systems.

I agree. all goes through 1 hose in and 1 hose out. Tractor and machine are open circuit. Tractor is rated for 19 gpm and the machine requires 8 gpm.

 

[roadhunter]

Was able to get a hydraulic schematic for the machine

View attachment HYDRAULIC SCHEMATIC.pdf