Using wheel loader with forestry mulcher.

[Davidov]

Hello.Been watching these skid steer machines with forestry mulchers(drum type) all over internet,it's amazing with such small engine they have (+-100hp) to be able to operate with those mulchers with no issues.My wheel loader have 260hp engine and his gear type hydraulic pump is i think 120 gal/min(450liter/min) capacity at 2700psi(180bar)...I know all skid steers have piston variable pumps,they don't have much flow,but hydraulic pressure is huge with them.I guess in hydraulics more pressure equals more torque ?,and more flow more hp ?.Anyway,could i expect to have large enough hydraulic pump in my wheel loader to run some smaller forestry mulcher ?.

 

[Mike L]

Possibly. But don’t forget that forestry machines are covered in skid plates, guards, large cooling packages, and heavy ply tires. Also most forestry equipment has a dedicated pump for the attachment whether it is a mulcher, felling head, etc.

 

[Tones]

CTL running mulchers have a hi flow setting at upwards 150 litres per minute @ 4500- 5000 psi, dedicated machines much more. Flow= speed, pressure = power then add required hp.
Hydrostatic drive to wheels is an important factor as well. Running a conventional loader transmission at WOT while trying to slow the ground speed ain't going to work.

 

[Davidov]

@Mike L It's not problem to add few removable guards,tyres are no problem ,cooling radiator for hydraulic oil i have bought over a year ago but haven't installed it for now,it's quite large,probably overkill for my loader but it can't do harm.I forgot to mention that i wouldn't do this profesionally,only for my farm fields to keep them clean and maybe some job or two for friends,nothing more.Also bare in mind what i plan to mulch is not thicker than 2 inch,i guess i could use flail mulcher not heavy forestry type idk...Anyway i want to have my machine for this,i want to use it when i want,how i want,for how long i want,i don't like depending on contractors ,also they are very expensive ,i guess because it is very,very,very rare in my area to see some machine,tractor,loader,excavator,anything ,with mulching head.

@Tones Ok so my pump could produce lighting speed due to its enormous flow,could i compensate that huge flow for low pressure ?,btw max working pressure is 3000 psi for my pump,but safety valve is set at 2700 to last longer.I know moving speed might be an issue,but my loader have really slow first gear,on full engine speed he is slower than human walk,grandpa walk.I use 1st gear only when loader is pushing heavy dirt and stone,for anything lighter i am all the time using 2nd gear all day long.As i say,i would not mulch stumps and what not ,just some bushes up to 2 inch thicknes at ground level.

PS,sorry for my broken english .
Based on this site,my hydraulic pump produces over 200 hp,it got to have power to run some middle size mulcher ....or flail mower....

Hydraulic Output Power Calculation, Output Power, Hydraulic Pressure Calculation

This calculator page enables you to calculate three parameters important to designing a hydraulic power pack.

hydraproducts.co.uk

 

[Tones]

The rotor speed on a forestry mulcher only needs to run at 1600rpm. 2 ways of achieving this is by hydraulic motor size and pulley diameters. Hydraulic motor size is the amount of oil required for 1 rotation.
If your loader has only one pump then working any function even steering is going to take oil flow away from the attachment so a priority valve system will be required.

 

[Davidov]

Was planing on adding that,steering and hydraulic distributors have their own pumps,but this main pump will still have to raise and lower mulcher head.But i was maybe thinking to limit oil flow for raising and lowering mulcher,some 10-20 gal/min(40-80l/min) for that operation while loader is paired with mulcher only, with some valves,or idk,i won't need it to lift fast as it does when i am using bucket on loader.So some 100gal/min(400lit/min) would still be available for mulcher.
My main issue is not knowing what size and type of hydraulic motor to search for.If my pump is gear type,should i pick gear type motor or it doesn't matter ?.
I again used that site i posted above to check pump displacement,so this pump i have on loader is somewhere around 15cubic inch/rev ,or 250cc/rev.And if i send part of the pump flow capacity for lifting and lowering mulcher,those numbers would be +- 12-13cubic inch/rev or 210-215cc/rev.

 

[Tones]

A hydraulic motor @ 210- 215 would be revving at the same speed as the engine. Going to a larger hyd motor reduces it's RPM's and increases it's torque, all the same principles as a reduction gearbox. You know the engine speed, figure out what rotor speed is required then with those numbers you can get motor size and pulley diameters to match.

 

[Davidov]

By engine u mean hydraulic pump ?.Ok so my hydraulic pump at 2000 rpm and 215cc/rev,would spin hydraulic motor of same cc at same speed ,ofc ?.
Could i maybe get some example of which model of hydraulic motor to look for ?,or maybe link to it,just to see as example what to look for.
I just search on google 200cc hydraulic motor ,and one of examples is this ...motor displacement is good ,but flow.....i only need almost 8 times that flow ...

BREVINI Motor BGEC 200cc D=25mm G 1/2“ (257BGEC200) - Spare parts for agricultural machinery and tractors.

BREVINI Motor BGEC 200cc D=25mm G 1/2“ - Product of the highest quality available only at www.agropomoc.com Check our offer included the best spare parts for agricultular machinery.

www.agropomoc.com

 

[Tones]

Engine= what drives the loader, hydraulic motor = what receives oil from hydraulic pump.
That motor isn't suitable, it's max RPM is only 305 and no casedrain. Rexroth is a brand name most manufacturers like FAE, Prinoth, Fecon use. Danfoss is another good brand.

 

[Davidov]

Ok,but what about hydraulic motor type ?,does it matter if its gear type or piston type ?.Should it be fixed displacement or variable ?.
My pump is gear type fixed displacement.

 

[Tones]

As far as I know none of the mulcher manufacturers offer a gear type motor. On the variable displacement versus fixed displacement thing, some like fixed displacement, others prefer variable displacement. I'm in the fixed camp. My reason is that if you are working to the maximum ability of the mulcher then it's going to be at maximum displacement. Therefore you're paying for something that's not being used and becomes something else to fix when it breaks.

 

[Davidov]

Yeah i could agree with u also on that one,fixed type it is then.Anyway thanks for helping me out,i have some info now for further work on this,hydraulics are really complicated xd ...or at least to me...

 

[terex herder]

Why do you need to beat the trees to toothpicks? That costs lots of money. Can't you just cut them off and pile them? If the pile is out of the way leave it to rot, or burn it after it drys.

 

[Davidov]

It's not trees i will be mulching,its this bushes like ...they can go up to 10-12 feet in height,but at the ground level they are not thicker than few inches.It's better for soil to mulch this and mix with ground little.And it would be hard to cut that and move to other place because this is all intertwined.Burning is not an option,it's hard to set these on fire,and even if u do,they will remain standing like that for years untill they start to root away or whatever ....beside i don't like fire on my fields,and it is against the law,i could lose subsidies.