Hydraulic Motor for Mower Deck?

[muddstopper]

I'm thinking about trying to make a boom/ditch/pond mower from a old 42" mower deck.

My tractor IH 424 only has about 8 GPM of Hydraulic flow would this motor be able to power a 42" mower deck?
Surplus Center - 0.58 cu in MGG20025-BA1B3 HYD MOTOR SIDE PORTS

SPECIFICATIONS
0.58 in.³ disp.
2000 PSI cont
2500 PSI int
3500 RPM max as pump
5000 RPM max as motor
2.51 GPM @ 1000 RPM
Reversible rotation
92 in-lb./ 1000 PSI
SAE AA 2 bolt mount w/2" pilot
Shaft 9/16" x 1-3/8" w/keyway
Ports SAE 10
Side ports
Size 5 1/2" x 3 1/2" x 3 3/8"
Shpg 5 lbs

If it will not does anyone have a recommendation?

Should I look for a smaller deck?

When I first read this, I thought you where talking about a small bushhog type mower. Took me a minute to realize you are talking about a lawnmower deck. I can say pretty positive that the motor listed in your first post most likely wont do what you need. To small and to short a shaft to make mounting easy. Not enough power being another problem.

The 1.cu cross motor that is listed requires 8gpm to run 1800rpms. This max's out your hydraulic capacity, but wont give you the tip speed on your mower blades to give any kind of quality cut. The 42inch deck on my rider is powered by a 20hp twin cyl engine. I havent checked pulley sizes, but I believe the pulley ratio to be 1:1. I have no way of measureing the engine rpms, but full power is probably in the 3000rpm range. Using my current mower setup as a basis, I feel you will either need to find a larger hyd power supply and purchase a hyd motor to match to get the power you need to run the 42in mowerdeck, or stepdown in the size mower deck and still face a lot of cost to get it to work right. I will offer this suggestion and that is, just find a running push mower and mount that to your boom arm. If you want something larger than a normal push mower, then consider one of those tow behind bushhogs like you pull with a ATV and mount that on the boom arm.

Good luck with your project and post pics when you get it finished.

 

[J_J]

For about a couple hundred, you could do this .

 

[jandrew156]

J_J, what RPM's are you getting from that 20" boom mower? Do you have a model# for that motor?
From my calcs, an effective mower tip speed should be around 15-20,000ft/min, which should be an RPM of about 2800-3500 or so.
I'm having a very hard time finding a hydraulic motor to pull that off without gearing (or belting) it up. (and then a pump to power it from the PTO!)
Looks like that works very well though!
I was planning on using a 2-stroke 4HP lawnboy mower for mine, but the banks I'm mowing are almost vertical in some places. The old lawnboy has a bowl carb, so it's starving for fuel.
Thanks!

 

[J_J]

Surplus Center - 0.7 cu in PARKER MGG20030-BA1A3 HYD MOTOR

Surplus Center - 1.61 CU IN CASAPPA PLM20.25S0-49U5-LOC/ HYD MOTOR

Surplus Center - 1 cu in CROSS HYD MOTOR 40MH10DACSC

 

[k0ua]

JJ, can we talk about case drains? I would like to know more about practical applications.. lets say the 1 inch motor to use as a power source to run a large string trimmer head on a FEL sticking out to the side. How much fluid will likely come out of the case drain? Will it need plumbing back to the tank or can you use check valves and route the case drain to the low pressure side of the hydraulic circuit. Example I have and A and B connector on my torque tube which are fed from the Remotes on the rear of the tractor, I have about 10gpm of flow and pressure will be somewhere around 2500 lbs. Do I need a smaller connector and hose to take the case drain to T into the tank connection.? As you can tell, I don't know much about hydraulic motors.

James K0UA

 

[J_J]

Using a hyd motor with case drain, the case drain must go back to tank unimpeded. Back pressure can cause seal failure.

This fluid lubes and cools the hyd motor.

I have all hyd implements for my Power-Trac, and the larger motors have case drains, and the PT has a QD for the drains lines to run everything back to tank. My wheel motors also have case drains.

Here are some excerpts from Hyd Machinery:

Seal Failure
High case pressure results in excessive load on the lip of the shaft seal. This causes the seal lip to wear a groove in the shaft, eventually resulting in leakage past the seal. If case pressure exceeds the shaft sealç—´ design limits, instantaneous failure can occur. The subsequent loss of oil from the case may result in damage through inadequate lubrication.

Mechanical Damage
The effect of high case pressure on axial piston pumps is similar to excessive vacuum at the pump inlet. Both conditions put the piston-ball and slipper-pad socket in tension during inlet (Figure 1). This causes buckling of the piston retaining plate and/or separation of the slipper from the piston, resulting in catastrophic failure.

If you can measure the case frain from a new motor, you can use it as a reference for determining the health of your hyd motor in the future.

The amount of fluid is a design feature, and would be different for different hyd motors.

 

[J_J]

Some more stuff on case drains.

Do not run the lines through a return filter.

Piston pump and motor case drain lines should be returned to the reservoir through dedicated penetrations. These penetrations must be higher than the unit’s case port and be connected to a drop-pipe inside the reservoir that extends below minimum fluid level.

 

[k0ua]

Using a hyd motor with case drain, the case drain must go back to tank unimpeded. Back pressure can cause seal failure.

This fluid lubes and cools the hyd motor.

I have all hyd implements for my Power-Trac, and the larger motors have case drains, and the PT has a QD for the drains lines to run everything back to tank. My wheel motors also have case drains.

Here are some excerpts from Hyd Machinery:

Seal Failure
High case pressure results in excessive load on the lip of the shaft seal. This causes the seal lip to wear a groove in the shaft, eventually resulting in leakage past the seal. If case pressure exceeds the shaft sealç—´ design limits, instantaneous failure can occur. The subsequent loss of oil from the case may result in damage through inadequate lubrication.

Mechanical Damage
The effect of high case pressure on axial piston pumps is similar to excessive vacuum at the pump inlet. Both conditions put the piston-ball and slipper-pad socket in tension during inlet (Figure 1). This causes buckling of the piston retaining plate and/or separation of the slipper from the piston, resulting in catastrophic failure.

If you can measure the case frain from a new motor, you can use it as a reference for determining the health of your hyd motor in the future.

The amount of fluid is a design feature, and would be different for different hyd motors.

Thanks, so there needs to be 3 connections... A B and case drain back to tank. got it.

James K0UA

 

[Kaliburz]

Here is something for reference/ideas....

Mowing Equipment :: Edwards Equipment Company

They have been making this setup for years (30+). I just bought one actually (the smaller mower), used, so I don't have the owners manual to give ya mower motor specs. But the motor they have is a direct drive, w/ case drain as mentioned. They have it set up so that on the return line, there is emergency by pass valve/cartridge going from the supply/pressure line. That's if you hit something and it spikes, the cartridge bleeds off the excess pressure from the shock, then closes when presses return to "normal" (like a blow off valve on a compressor). I'll take a gander and see if I can find a manufacture and or part number on the motor.

I'm in the middle of making a mount to get it on the front of my tractor so I can mow under the grape vine rows/trellis (gonna make something like the double set up in the link, someday.) The one unit w/ arm cost me $3K....

If you were going to use an old PTO mower as a starting point (even if it was like a finishing mower w/ 3 blades driven w/ a belt), you could have used one of those hydraulic motors that have the 540 PTO splines on them (or similar spec). Surplus Center has them. It would just be a matter of making a coupler and torque arm for the motor.

I bought one a while back to convert a PTO auger to hydraulic (never finished the project, bought a dedicated unit at auction). But I matched it so that I was using about 70-75% of my tractor hydraulic flow to get close to 500-530RPMs (I have a JD closed center hydraulic system). When I mow w/ the PTO, I NEVER get to the full 540 PTO and have always liked the cut (if not slow down...) of our old JD 6' field mower.

That picture of a gas powered mower on the end of a boom, been there, done that. Took a buddies old, smoke blowing mower, made a bracket for it and put it on the end of tool bar to get close to the grape row years ago. Was slow, really easy to overload a lawn mower trying to cut tall weeds. Out fit out of NY made a unit for their grape hiller (side mount) years ago before hydraulic power was "mainstream".

 

[Kaliburz]

I looked at my Edwards mower. It uses a Cross motor and it has a case drain. The top has these numbers: 5Z4204 On the side: M10 By the mounting flange: 24 12RD (I think it had more on the flange, will look again, it was dark when I looked).

If I recall, the tractor it was made for had a capacity of 6 or 7 gallon's per min. I'm using a needle valve on mine (Deere w/ a higher flow) to control the motor speed.

The model of mower I bought was the DT5300. I'm actually in the middle of making a different mount to get it working w/ my tractor.