Rear PTO to a mid mount mower idea

[electrycmonk]

so I have been curious... there are several ideas out there but, I have not found one close to what I want to see how costly it will be.

Its a well establish adapter to put a PTO reverser on tractors or Unimogs for snow throwers etc.

This design I find very enlightening because it is talked of with no pictures. A closed loop PTO hydraulic pump and "motor" with 2 hoses and a sealed system?
I'm quoting the post in this other thread for simplicity: from: www.orangetractortalks.com (for just keeping the honesty solid)
***I went to Princess Auto, talked to there hydraulics guy and he paired up a small hydraulic pump that powered a small hydraulic motor. two hoses, so closed loop system( no tank needed). Nice thing was it was totally sealed and zero maintenance. It was easy to make up the mounting , made templates from plywood to get holes just right.This was 10-12 years ago, maybe $300 in parts.***


Now, here is the thread of someones "reverser" for their antique tractor (for continuing the honesty from where i got the data):Is there no "how not to" heading?
this is the 2 pictures of detail I saved from that thread.



NOW, for clarification. Either go the route of that "sealed hydraulic simple system" i cut-n-pasted above OR getting a chain drive multi sprocket system that will mount around the reciever hitch to point a PTO output shaft towards the middle of the belly of the tractor.

I'm about to own an old L2250 Kubota 2WD diesel tractor that needs a serious cleaning. I want to see if I can realistically setup To run a belly mower. I will be acquiring a nearly new belly mower for ~$125 and its at least 60" cutting width and its also a Kubota unit.

there are the facts.
the tractor this idea will be seriously wanting to get a real world cost idea to see *IF* its worthwhile to say i got it done."

 

[alexpops]

I'd be leery of the hydraulic option without a tank especially. You'll have 21?hp at the PTO (540/1000) so at 80-90% efficiency (call it 85%) maybe 18hp from the pump and if the motor efficiency is the same, 15hp at the blades. This assumes you are running at full pto rpm of ~ 2400 at the engine. Add to that the mid pto option was set to run at 1080/2000 (design speed for the mm deck you are getting). So ... without a tank, you'll either starve the pump of oil, or build up pressure/heat & wear out the motor/pump components quickly. At 2400 engine RPM, you're pretty much locked into low range to max of H1 if you have flat terrain with no trees.

Based on input HP from the pto, you're looking at 13.5 GPM pump which I only see in 1000 rpm 21T flavor at Surplus center and only one is in stock. for 6T spline you may need to drop down to 11.4 GPM or go up to 16.6 GPM -- none in stock. Price ==> $500-1150. Add in a 1.5cubic inch high speed motor that'll take the GPM & spin @ 1800-3000 rpm for $330. Another couple hundred for lines/fittings/adapters to attach to the mower deck, & you have a working unit for between $1000 and $1800 that still needs to be tested/tweaked for performance & longevity. If you need a tank & cooler figure another $500 plus a fabbed up carry-all to transport plus more lines. While there, to protect the motor & pump I'd add a filter head & filter. So now you are at 1700-2500 for a one-off system that may or may not be up to your task. This all assumes you have materials & do your own fab/welding for the carry-all. Add those to the kitty if the work is farmed out.

The simple reverser could be done cheaper if you have a lathe and/or mill, but you still need to fab up the mount & figure the cost of bearings/gears/cogs/chain/seals & I'd want some lubrication on the chain/gears so a housing to hold it all in gear oil.

What are you mowing with a 60" deck? pasture? better off with a bush hog or small flail. lawn? zero turn or dedicated garden/mower if you're wed to the idea of a belly mower. either would probably be cheaper than the cost of making a good hydraulic set-up, & either would probably be better for the task than a belly mower.

 

[electrycmonk]

IT was a hobby idea to see if I was able to actually make it work....

as for the hydraulic pump and motor setup ... wow $1000-2500 is a wake up for this idea.

I have a complete system for the 3 point backhoe that i was thinking of using for the testing. its a PTO Pump, inline filter, tank and plenty of hoses but, the "motor" is what i don't have. the "motor" will have the PTO output shaft that the mid mower deck will connect up to with its driveshaft.

as for where? its a 2.5 acre yard on a slight hill. I've been using a Ford 917 Flail mower and enjoy it alot. Have no plan to get rid of it either.

 

[Richard]

I don't expect this to have much value to your conversation but, I happen to use a hydraulic mower on the back of my International 1066.

Mower is a 15' Alamo (originally 'Terrain King' until they were bought by Alamo)

Attached to the PTO on the back is a speed increaser. It takes (depending on the internal gearing that's in there) either the 1,000 PTO or, in my case, it's attached to the 540 PTO.

Multiplies the 540 by a factor of 4 and now, the hydraulic pump hangs off the speed increaser to get the hydraulics up to their needs.

In my case, I've got both PTO's so the bracketry had to be designed to not block the 1,000 PTO.

 

[Richard]

Without recalling exactly, I think this holds 15-25 gallons of hydraulic fluid between the tank, hoses and motors. They actually designed into the folding wings, some internal tanks and these are the cooling tanks. So the oil goes from tank to pump, to Motor 1, then motor 2, goes to cooling tank, back to main tank, back to pump

Or something similar to that.

 

[hiddentacocatneddih]

The power loss on such a small tractor to run the mower hydraulically I figure would limit you to 48inch or so deck. Probably end up with 10-15hp usable at the deck

Then aux equipment needed, tank, cooler probably and such

Shaft drive would be the way to go

 

[electrycmonk]

The power loss on such a small tractor to run the mower hydraulically I figure would limit you to 48inch or so deck. Probably end up with 10-15hp usable at the deck

Then aux equipment needed, tank, cooler probably and such

Shaft drive would be the way to go

this is why i posted the neat pics of the chain driven shaft flipper.

I was figuring either a mototrcycle chain setup or a cam chain setup from like a typical v8 block. snag a couple extra sprockets with sealed bearings and then, drill a few holes in the thick sheet of metal and test it out. granted the chain will need safety shielding and if it works good ... then make a lube shield?

the deck will actually go back to a smaller kubota G5200 or 6200 that is currently dormant that it came from.

This all stemmed from seeing what this bunch of folks had done for these seriously old Farmall tractors with belly decks and snow throwers.

 

[alexpops]

Like I said earlier ... the reverser can be done cheaper and better then the hydraulic set-up, BUT you still have to factor in the speed doubler in your sprocket/gear set-up. As I understand it, the stock mid-mount pto operated at double the speed of the rear pto & if you have a mid-mount mower designed for that speed (1080/2000 rpm), you'll need to factor it in to your set-up. Add in "safety police" concerns for shielding of the pto shaft spinning at those speeds under your butt (if the tractor isn't already set up with them) in case something lets go. Also need to measure your distances to make sure your riding angle on the mid-pto isn't overstressing the u-joints when in operation.

 

[bcp]

Clean, repair, paint, relabel the mid mount mower. Sell it. Buy a rear mower.



Bruce

 

[Vigo327]

First thing.. are you sure the l2250 doesnt already have a mid pto??? It had that option and would seriously simplify things.

If not..

So i have this 54" 3pt belly mower (yes, Three Point Belly Mower) that runs off a normal 540 pto. All it is, is a normal right angle gearbox like you'd find on any bush hog or 3pt finish mower or what's on the mower deck you're talking about, that has a large belt pulley on its output. That belt extends forward to the totally normal mower deck.

Im bringing this up because there is a possibility you could take a mid mount mower with a gearbox on it, such as the Kubota g5200 or whatever deck, and relocate that gearbox to the rear of the tractor, turn it 180 so it faces your PTO shaft, and simply run a much longer belt. You would end up with something that looked similar to the mower above, which is a Continental Belton KTR-54 if you wanted to look into it a bit more. You would have to fabricate a rigid mount from the mower deck to the gearbox, unless you wanted to install a belt tensioner in between that could make up for minor changes in the distance between them as the gearbox stayed fixed to the rear of the tractor, and the deck 'floated' on its hangers a bit.

It looks like the l2250 had 2 spds for the rear pto and 2 speeds for the mid pto, and 'high' gear on the rear pto is similar to 'low' gear on the mid pto, so it's possible you wouldn't have to step up your rear pto rpm at all, although if the G5200 mower deck is designed to run closer to 2000 rpm you would still need a simple set of sprockets (just 2, not 4!) to create that 'step up' ratio before going into the stock mid mount mower gearbox.


It's a lot of fabwork. Mid mount mower decks with gearboxes on them are pretty application-specific if you actually want to use the gearbox. All the gearbox does is drive a belt pulley so there may come a point where it's easier to ditch the gearbox and just get a belt over there, or start with a belt-driven deck to begin with which would basically only need a mule drive like an old garden tractor, Farmall Cub or Lo Boy.