Anybody have source for a 540 RPM hyd motor to run tractor attachments on PT?

[m5040]

I would like to fab up a adapter to run tractor 3pt hitch - 540 RPM - attachments. I would think that this should be one of the most used modifications, but a search didn't come up with anything.

The motor would be tractor specific as the psi and flows are different. Just looking for a starting point.

 

[LouNY]

Here you go;
Ag PTO Output Hydraulic Motors | Hydraulic Motors | Hydraulics | www.surpluscenter.com

 

[m5040]

Thanks, has anyone out there tried to use one on a PT?

 

[MossRoad]

You should figure out how many HP your hydraulic PTO can supply before you continue down this path. I think as a group, many years ago, we figured the MAIN PTO on the PT425 will supply something like 11.8HP. I don't have the calculations at hand, but I'd guess some serious searching of TBN could bring up the threads that discussed it.

What 3pt implement are you considering? Just curious.

 

[MossRoad]

I bumped up a thread on the discussion in the PT forums for you. Might give you some ideas.

 

[MossRoad]

There are several folks that did build adapters to use 3pt implements with a splined shaft, and there are several that have have just installed a hydraulic motor directly onto the 3pt implement and eliminated the shaft.

Also consider that any adapters, for example, skid steer quick attach plates and 3pt implement adapters add significant weight to the FEL arms. On these smaller units, every pound counts.

 

[m5040]

For my other tractors, snow blower, rotary cutter 5', finish mower 5', flail 5', Beefco wood chipper, Herd seeder, used to sand driveway, Farmi winch, generator. Since I have them I think it would be nice to be able to use on PT, even if it only works on fair side. I am not buying attachments to use, just trying to make use of what I have. These are plans for a 1430.

 

[m5040]

Roger on the weight, it adds up fast. Especially when going from PT to melrose-Bobcat skid steer type. I have a 3pt to skid steer and it must weigh over 100 lbs by itself, at least that's what he feels like when I am installing it.

 

[MossRoad]

Sounds fun. Keep us posted. :thumbsup:

 

[agjones]

At the full flow and pressure of your 1430, 12gpm@2500psi you have about 20hp that can be applied to a 5.1ci hydraulic motor to yield 540rpm.

Calculations are rounded and from here :
Hydraulic Calculations | Fluid Power | Advanced Fluid Systems

I've converted a few and really prefer to go with a chain sprocket mounted on the hydraulic motor that drives the implement gear box.

Keeps the weight down. It's easy to still power w a tractor (take off the chain) and generally allows the orientation of the tool for safe, effective use.

 

[m5040]

Excellent idea. I will keep it in mind about the chain drive. Right now I only have a PT180 but looking real hard at the PT1430. I do wish I could find a low hour used one. I don't need that new tractor smell.

 

[agjones]

I think you'll find that the geometry of a tractor pto shaft really handcuffs a pt. That's why I went to the chain drive. Your hydraulic system is already protected by relief valves, so the shear pin etc is not necessary.

With the chain drive, I'm not limited to 15 degrees flex under power... I can power at any angle the loader arms can make.

 

[m5040]

At the full flow and pressure of your 1430, 12gpm@2500psi you have about 20hp that can be applied to a 5.1ci hydraulic motor to yield 540rpm.

Calculations are rounded and from here :
Hydraulic Calculations | Fluid Power | Advanced Fluid Systems

I've converted a few and really prefer to go with a chain sprocket mounted on the hydraulic motor that drives the implement gear box.

Keeps the weight down. It's easy to still power w a tractor (take off the chain) and generally allows the orientation of the tool for safe, effective use.

I will have to have a couple cups of coffee before I try that formula. But in your experience what would be the real life difference between the 4.95 motor (which wants 2576 psi and 17.1 gpm) and on the other extreme, the 9.59 motor (which wants 2780 psi and 19.7 gpm) when using the PT1430 PTO at 2500 psi at 12 gpm? Since the PT has insufficient psi and gpm would the larger motor still provide more torque or would the smaller motor due to it being provided with psi/flow closer to it's requirements? {using the surplus center's tractor splined motors at Ag PTO Output Hydraulic Motors | Hydraulic Motors | Hydraulics | www.surpluscenter.com } provided by LouNY.

 

[agjones]

The larger displacement might offer more torque, but it's not much use at less than 300 rpm.

 

[m5040]

OK, I think I got it, the larger motor will be for applications like a rotor tiller or drill head low rpm and high torque. Small motors for high rpm like mower or leaf blower.

 

[agjones]

If you want to power a tractor implement using the existing gearbox, you need a hydraulic motor that can convert your hydraulic flow into 540rpm or pretty close.

If you want to eliminate the 540rpm gearbox then you want a hydraulic motor capable of generating the tool rpms. In a recent chipper conversion, I used a high speed, low torque motor, similar to that on a pt finish mower deck To get 2300rpm to the chipper head. At 30#x2300rpm ,the chipper head mass is what powers through the chipped materials. The hydraulic flow is just maintaining the rpm. Same w other bladed implements.

In the tiller example, it's the torque developed in the motor that powers the next bite of soil, not the rotating mass of the tines.



So yeah, low speed high torque is a good fit for tillers, wheels etc. And small displacement hydraulic motors are a good fit when high rpms are required.

 

[MossRoad]

I like to think of the motor displacement as gearing. Tiny motors are high speed/low torque. Larger motors are medium speed/medium torque. Even larger motors are low speed/high torque.

 

[MossRoad]

Take a look at the different attachment pictures and compare the motors while thinking about speed...

 

[m5040]

Take a look at the different attachment pictures and compare the motors while thinking about speed...

View attachment 622095 View attachment 622096 View attachment 622097

That trencher motor looks pricey.