Kubota hydraulics kx41-3v

[Paul wetwood]

Hi not sure if this is the correct discussion board.
However I want to buy a forestry muncher here in France
this is what the company is saying and I am not sure if my kx41-3v is compatible
The mini-excavator must be equipped with a double pump: one for hydraulic functions and one for travel.
The head rotor rotates in both directions, so the machine must have a double-acting circuit (pedal or lever).
The pump requires a third drainage hose, which must be connected directly to the tank.
It is equipped with a mounting plate for coupling to the mini-excavator. The pump has three hoses: two for supply and return, and a third for drainage.
is it suitable for my mini digger

 

[V8Druid]

Hi not sure if this is the correct discussion board.
However I want to buy a forestry muncher here in France
this is what the company is saying and I am not sure if my kx41-3v is compatible
The mini-excavator must be equipped with a double pump: one for hydraulic functions and one for travel.
The head rotor rotates in both directions, so the machine must have a double-acting circuit (pedal or lever).
The pump requires a third drainage hose, which must be connected directly to the tank.
It is equipped with a mounting plate for coupling to the mini-excavator. The pump has three hoses: two for supply and return, and a third for drainage.
is it suitable for my mini digger

firstly what they refer to as " the pump " should be 'the motor', which drives the flail head.
not unusual for hydraulic motors to need a case drain, which must return on an open line, directly to your tank (there must be zero back pressure on a case drain line and must therefore be an open direct line to tank and NOT flow through any type of valve).
can not over emphasise the importance of a free to tank return for the case drain as without it, it will blow the motor seals very quickly, as back /case pressure will develop and need to escape PDQ
the case drain caters for leakage within the motor's casing, from the rotors and must be able to free flow without restriction - (it's usually a 1/4" hose/line).

the fact that the flail's drive motor is capable of being driven in both directions is an advantage if you have a double acting circuit supplying it (can reverse to clear blockages).
however, the motor should still be capable of running on a single acting service (one feed, one return) and one can ensure it rotates in the desired direction by making sure the feed and return are connected the suitable way around. reversing this would make the unit run 'backwards' to that desired.
so in theory it is not essential for the machine to have a double acting service to run the flail, but damned convenient - there are ways of making a single acting service reversible without too much faff also

as far as your particular machine is concerned, I have no experience of the model so can't answer that one, but others will be able to.
what you should be more concerned with is whether your machine has sufficient flow to actually run the requirements of the flail's motor?
it is also worth asking if the flail's motor comes equipped with a cross line relief valve, as without one, the motor will want to stop dead, as soon as the oil supply is disconnected, instead of running down slowly, as the CLRV will permit and will give the unit a very hard time.

 

[Paul wetwood]

Thank you for taking the time to answer
Still not sure about doing the free to tank return. Do you know any utube videos that might help
Kind regards paul

 

[V8Druid]

Thank you for taking the time to answer
Still not sure about doing the free to tank return. Do you know any utube videos that might help
Kind regards paul

it's quite simple - you need to run a case drain line from the flail motor's case drain fitting, up the dipper, down the boom and then either connect into the tank, on a spare fitting, into the tank, or find a free/open return to tank, already plumbed into the tank and tee into that. there must be a fitting there already somewhere (and not into the return filter housing - that can induce back pressure - low, but pressure all the same - it MUST BE FREE FLOWING to the tank)

 

[CPS]

Your machine wouldn't be ideal for a forestry mulcher.
What do you want to cut? We always match the flail/mulcher ro the machine.
Id recommend a Femac T1 for that machine