Log splitter pump and valve questions

[phill3003]

Hello new to forum here lots of great projects to look at.
I have build splitters before but not with a axial piston pump this is where i need help from the experts as this is new to me
I am building a log splitter. Here is what I have for parts it will be a heavy duty unit for use in our firewood business
7" x 30" cylinder
68 lbs a foot H beam i think it is 10 wide and 10 high
2.2 L Kubota Diesel for power
will have to run all 1" pressure hoses I am thinking
log lift
box wedge

pump and valve are where I have questions do i need a closed center valve to run this and do I want to run in load sensing mode or pressure compensating mode? This is the pump I just recently won on ebay.
Vickers Pvh740icrf1s10ic31 Hydraulic Pump | eBay axial piston pump model PVH740ICRF1S10IC31 from ebay link to pdf for pump http://www.devcocorp.com/american/vickers_h_series.pdf

I will post a few pictures later this afternoon it is raining cats and dogs out now thank god it is not snow

thanks for any input you might be able to give me:thumbsup:

 

[oldnslo]

The IC control allows several features that you may or may not require. It has D03 mounting pattern so that you can install different control options. Some options are multiple pressure settings via electrical control. Single pressure with unload option for standby or start-up. Drops pressure to around 290 PSI.

Since this is an Industrial pump, pay close attention to the inlet conditions and speed of 1800 RPM max. It will be more sensitive to cold weather operation than a gear pump and It will also require better filtration than a gear pump.

Valves: Closed center and if going to running a lot of functions would also consider load sense for energy savings and less heat generation. Will the valves be manually operated or electrical control. Since you spent the money for an expensive pump you may want to also purchase valves with built in pressure compensation for each section so that the speed of each function does not vary with load changes. Example of valves: Sauer Danfoss PVG, Rexroth M4-12, etc..

Right hand Rotation as viewing the drive shaft. Most mobile pumps are left hand so make sure you also take this into account.

Note: Model should be PVH74 QIC not OIC. The Q is for Quiet Industrial version.

Good luck

 

[phill3003]

Right now I am thinking I will only be running a log lift and the main splitting cylinder but i may add a jib crane to it and a set of tongs in the future
my concern is the log lift will launch logs over my head with out the proper controls on it?
the Kubota is rated 46 hp is off a reefer I plan on turing it up a bit what do you think this will require HP wise
thanks for your input.

 

[oldnslo]

Horse power required is a function of flow and pressure. This pump will theoretically produce 35 GPM at 1800 RPM.

HP formulae is GPM times PSI divided by 1500 which allows for around 85% efficiency

At full flow you could generate around 2000 PSI with 46 HP

Yes you could launch logs at full flow but that is one of features of load sense. You can reduce flow with out burning HP and creating excessive heat.

 

[phill3003]

I finally remember to take some pictures of splitter most if it is tacked up lots to do but need to get after it.
so for a valve to run the main cylinder i need at least 30 gpm I am thinking
and need an additional control of some kind that goes on the do3 mounting plate to control pressure compensation?
I talked to the carrier guy that i received the kubota from and he says we can make a little over 100 hp with pump mod and turbo that looks like it will be needed

 

[oldnslo]

At what RPM does this motor develope 100 HP? My bet is that it is not at 1800 or less. If you over speed a piston pump to much at full stroke bad things do happen.

Valve size I would say you good.

 

[phill3003]

That is at 3200 rpm and around 20 lbs of boost. I have a 2 to 1 speed reduce that could be put into service if it wont work whit factory hp settings. We will try it how it sits first. it is currently set to run at 1800 rpm NA.
the main question I guess is will this pump work as is with a block off plate on the compensator or do I need additional controls I have red the pump info a few times but get more confused the more i go over it thanks for you input oldnslo

 

[oldnslo]

Phill,
You need some form of external relief to limit your max system pressure. Just placing a cover on the compensator will allow the pump to run at infinite pressure and the weak link will break / explode. Page 11 of the data sheet shows a hydraulic diagram for the "IC" control. The outlet port is connected internally to both ends of the compensator and if the spring end is not vented it will never allow the compensator to destroke the pump.

 

[phill3003]

thanks that is what I was wondering so I need an external relief in addition to what i have to make this work properly I will have to call hydraulic guys here in town today and see what I can find out thanks again

 

[oldnslo]

If you want the pump to act as a variable volume pressure compensated you do need a relief for the pilot flow / spring chamber on the compensator. This will be low flow and Sun Hydraulic make relief designed for controlling pilot flow. Some valves sized for higher flows will be unstable at this low flow rate and can cause the pump to become unstable or hunt.