Hydraulic power pack build

[truckinfouble]

I am eventually building or buying a 60" Brush Cutter for my Mahindra 4540. Don't worry, there will be extensive safety cage work done lol. That being said I need to build a Hydraulic Power Unit for my 3 point to power the cutter since my tractor system would be insufficient. My big question is, while there are many motor options for low flow 16-21 GPM range, and Prince makes a pump that makes 21 GPM @ 2000 psi using the 32 PTO hp my tractor has available, are there any other pumps with a higher PSI or hydraulic motors that are up to mower work at the 2000 psi range? Most commercial mowers I see, even the low flow, still seem to need 3000 psi.

 

[truckinfouble]

Forgot to mention if I build the mower I am planning on the Hydraulic motor connecting to a gearbox. The rotating mass will be around 280 pounds with a tip speed of 11-14000. Any advice on pump or motor type from those experienced with hydraulics will be greatly appreciated. I have seen the Prince PTO pumps as well as one that uses a gearbox to increase PTO speed from 540 up to 1000 and a higher pressure pump.

 

[stuckmotor]

I must have missed something. Is this brush cutter to mount at the front? I don't understand why you don't just buy a rear mount brush cutter and power it with the pto. Maybe I don't understand what you mean by Brush Cutter.

 

[truckinfouble]

Yes front mount. I have a 72" for the rear that does great for small brush and grass, but I want a front mount to push into for the 30 acres that needs mowing between the planted pines. We are in a drought here and control burning in not allowed due to extreme dry conditions. By pushing in I can see better what I'm doing

 

[truckinfouble]

Baumalight mulcher MF760 on tractor loader - YouTube

 

[Farmerford]

I am rusty with pictures and this homemade attachment has been extensively modified since I built it over 10 years ago, but it may give you some ideas.

It is a 48" Bush Hog Squealer on a Kubota Grand L4330. I don't know how your tractor compares, but a 60" mower would be heavier than I would like hanging way out in front like it does. The Prince 4.9 cu in/rev pump transmits about 11 gpm to the Charlynn 4.7 cu in/rev motor; the 4330 pto is about 39 hp so I am not getting nearly the full power to the mower (perhaps 14 hp at best); the motor and pump are smaller because I originally built it for a smaller tractor. It works well enough that I probably will not upgrade until something breaks since a new pump, motor, and larger lines and fittings would be about $2,000.


Two quick pieces of advice.


Use a 48" or 54" mower at most and a lighht duty one at that to keep weight down.


Keep motor and pump about same cu in/rev so that the pump will turn at the same rpm as the pto. That way you will not need an extra speed increasing or decreasing gearbox or pulley.

Send us pictures.

 

[truckinfouble]

Thanks Farmerford. The Mahindra 4540 has a lift capacity of around 2200 pounds. I'm running a 650 pound root rake with no issue so I figure on keeping the mower around the same.

 

[stuckmotor]

Yes front mount. I have a 72" for the rear that does great for small brush and grass, but I want a front mount to push into for the 30 acres that needs mowing between the planted pines. We are in a drought here and control burning in not allowed due to extreme dry conditions. By pushing in I can see better what I'm doing

Makes sense to me. Thanks for clarifying.

 

[Rock knocker]

View attachment 509370

Oh, I see how you mounted the pump. It's a standard PTO pump, and you fixed it to the frame and used a piece of ag spline, held in place on the front by the shaft and detents. The shaft is long enough to go thru the pump and a female spline and bolt keeps the entire assembly in place.

Awesome idea.

 

[truckinfouble]

I think it is a great idea that helps hold the pump more stable. I just need to figure out which hydraulic motor to use now that will supply enough torque