Tractor hydraulics to run skidsteer attachments

[CheckerBill]

What size[if any]Kubota[other brands too] do you have to go to to get hydraulics the same as a Skidsteer Loader? I want to run hydrolic skidsteer atachments

 

[J_J]

Skid-steer attachments use flow rates up around 25 to 45 GPM's. The tractor PTO pumps put out about 21 GPM, at 2000 psi, at PTO rpm of 1000 rpm. 45 GPM, at 3000 psi, takes about 92 HP. 25 GPM at 3000 psi takes about 51 HP. Just look for a tractor that will put out GPM's in the 24 to 45 GPM range. It would be great if you could get the pump driven off the front of the engine. To get that large GPM, and pressure, you would have to have a pump displacement of 5.2 cu in, turning at 2000 rpm. So if that takes 92 HP, then you are looking at a tractor, capable of about 125 to 150 HP.

Some of the attachments are designed for low GPM, and vary in size.

Do you have a particular attachment in mind?

Based on the attachment size/width, and hyd motor, you can determine if a Skid-steer or tractor can handle it.

 

[dfkrug]

What size Kubota do you have to go to to get hydraulics the same as a Skidsteer Loader?

How about this size? The Kubota SVL75 has a 19GPM implement pump, and
runs at 3555psi.

Honestly, you can't expect compact tractors to come close to what
skidsteers or excavators can deliver. Even a mundane Bobcat S185 can
do 17GPM at over 3000psi. You have to go to Kubota's largest
M-series utility tractors to get that kind of flow, and I suspect that they
put out less pressure.

Then, the SS's also offer a "high flow" option.

If you want to run hydraulic implements, you really need to have them
sized for tractors, rather than SS's. That is what I do.

 

[CheckerBill]

JJ
What I have know is a Bobcat 1600[basically a Bobcat 763]is has 15gpm/2200psi@2800rpm. The snow blower is a McKee 3ph converted to hydraulically driven using a CharLynn/Eaton 103-1036-101 hydraulic motor. Using a replacement chart this motor seems to be 5.9cuin 590rpm 1425torque 1840rpm.All the compact tractors and even ones a little larger don't seem to come near this. I have a worn out Ford 2000 now.

What I want is a 4WD Farm Tractor with a demountable FEL so I can mow fields in the summer-FEL really gets in the was mowing-put the FEL on when I need and in the winter put the FEL on and mount the snowblower.

I guess the alternative is to mount a hydraulic pump and tank on the 3pth but then there's a cooling issue

 

[J_J]

CheckerBill,

Turning that motor at 599 rpm, requires 15.3 GPM's, and will develop about 1879 in lbs at 2000 psi. One of the larger PTO pumps can supply that GPM. However if you need to turn that hyd motor at 1840 rpm, then you need about 47 GPM's. That kind of GPM is only found on Skidsteers in high flow, and high powered tractors, and large trucks.

If you have a pump turning 2000 rpm, and a displacement of 5.9 cu in, you can push about 60 GPM's. The design of the pump will determine the operating psi.

If the motor can operate with those specs, then it can develop about 59 HP.

The HP required to drive the hyd pump is about 70 HP

 

[CheckerBill]

Thanx JJ
Turning that motor at 599 rpm, requires 15.3 GPM's, and will develop about 1879 in lbs at 2000 psi.
***So I'm on the money at 15GPM @ 2200PSI with my 1600 BobCat***

One of the larger PTO pumps can supply that GPM.
***were do I find one of these? and how much hydraulic will I need and how to keep it cool***

However if you need to turn that hyd motor at 1840 rpm,
***I see no reason why I would works ok know***
then you need about 47 GPM's. That kind of GPM is only found on Skidsteers in high flow, and high powered tractors, and large trucks.

If the motor can operate with those specs, then it can develop about 59 HP.
The HP required to drive the hyd pump is about 70 HP
***This is the HP I'll need at the PTO to drive a pump to get 15GPM@2200PSI? I sure don't need a tractor that big! I wanted to use a Tractor like a Kubota L4400[36PTO HP] or a BobCat CT440[30PTO HP]***