Hydraulic pump and motor questions

[Pooh_Bear]

I have a vertical shaft engine.
Can a hydraulic pump be mounted vertically to this engine.
Should it be direct driven or can it be belt driven.

I have a 46 inch mower deck.
What size hydraulic motor would it take to run it.

And finally, I want to mount this all on a frame
and use a hydraulic motor to propel it.
What should the specs be on this motor.

If you haven't guessed already I'm thinking of building
a riding lawn mower with everything powered hydraulically.

My big question for now is, can a hydraulic pump be mounted vertically.

Thanks.

Pooh Bear

 

[bobodu]

I mount them upright all the time. Pump don't care as long as it's filled with oil.
I also like to run them off a belt. It gives some measure of protection like a shear pin and allows me to change a pulley it I want more flow or pressure.
Now before someone points out the pressure thing...I mean I have had pumps that would slip the belt before getting the pressure up to where I wanted it. A larger pulley on the pump solved this.

Take a look at your deck and see what kind of reduction the present pulleys provide as to speed needed for the deck. Most small engines run in the 3200 to 3600 rpm range. Be prepared to spend a lot on oil and carry it all around as well as some way to cool it. This is another can of worms but figure on 15 gallons or more.

 

[tanglefoot]

Bob,
I'm wondering why you would need so much hydraulic fluid on one of these small machines. The reservoir on my Ford 4500 fel has only a 5 gallon capacity with its 23 gpm pump. It works quite well.
Butch

 

[Opti-Mist]

Consider the load cycle. On the 4500 it is intermittant where on the mower it will be continuous. Load = heat.

 

[bobodu]

Yep...heat. Add another motor to move the thing and you'll be up to frying temp in no time.
Although I have never stopped to look at one,I imagine the golf course mowers have some pretty big oil coolers. The highway bank mowers have a big tank on the left side of the cab and that also acts as a counter-weight.

Oh...forgot all about this....another reason to run the pump off a belt on a mower is that if you hit something with the deck and that motor turns into a pump....you won't bust a crank on the engine. Ideally, you might wanna consider a shear pin or something like it on the deck.

 

[westcliffe01]

Get a gear pump for powering the hydraulic motor on the mower. Take a careful look at the maximum rpm for both the pump and motor. The mower spindles typically turn pretty fast. Many pumps are rated to turn at 3600rpm. You will need a high rpm hydraulic motor like these listed here:https://www.surpluscenter.com/sort.asp?UID=2009081921305432&catname=hydraulic&keyword=HMHS

And the previous poster was right that you would need a substantial oil cooler with an electric fan to move air through it since ground speed is typically low.

 

[Pooh_Bear]

Wow, a lot to think about. Didn't consider the heat issue.
Glad to know I can run it using belts and pulleys. Simplifies things.
It will still end up being bigger than a regular lawn tractor.
Mite as well add some extra capabilities while I'm at it.

Still haven't figured out how to get the variable speed to drive it.
All I can think of is one of those variable flow controllers.
Need to be able to just creep along, or as much as 10mph.

Pooh Bear

 

[mjncad]

Be sure to post pictures, this sounds fascinating.

 

[bobodu]

You're also gonna need either a rotary flow divider,a double pump or two pumps of you want to run the drive hydraulically.

 

[RPW]

You might want to get some specifics from the people on the hydraulic board. Wayne comes to mind at the moment. I found (but don't remember where) that you typically want 1 gallon of resivoir for each gpm of pump. This also serves to allow micro bubbles to work there way out of the oil (prevents foaming). I've found that working with hydraulics is pretty straight forward and interesting but v-e-r-y messy.

 

[jas67]

I have a vertical shaft engine.
Can a hydraulic pump be mounted vertically to this engine.
Should it be direct driven or can it be belt driven.

I have a 46 inch mower deck.
What size hydraulic motor would it take to run it.

And finally, I want to mount this all on a frame
and use a hydraulic motor to propel it.
What should the specs be on this motor.

If you haven't guessed already I'm thinking of building
a riding lawn mower with everything powered hydraulically.

My big question for now is, can a hydraulic pump be mounted vertically.

Thanks.

Pooh Bear

Find your self a Case 44x series tractor (442,444,446,448), or one of the newer series 40xx.

These are fully hydraulically driven with hydraulically implements. They can also probably be had for less than it will cost to build one.

 

[J_J]

Pooh_Bear,

Just how serious are you about the hydraulic driven machine? There is a whole lot to think about. Which end are you going to start from? If you start with the engine, the HP available will determine the pump or pumps that you use, and that will determine the size of the motor, and what the deck size will be, and how many blades, etc. . You really need variable speed pump, and hydraulic motors, or a hydrostatic transmission, and wheel assemblies. Filters, reservoir, fluids. Maybe brakes. It would probably be easier to modify something. There are thousands of hydrostatic tractors out there, but very few have a hydraulic driven deck. A hydraulic motor increases the cost of the deck about $200.00.

If you start with a certain size deck in mind, then you have to compute the required HP to drive the deck, and that will determine the size of the hyd motor, and back that up some more to the pump size, then to the engine, plus the Hp necessary to drive the machine. Consider the size of the tires/rims. If you can hunt down all the parts, you can build one for about 1/2 of a new machine. If you are a good scrounger, the cost would be less than that.

The adapter below is what you would use to mount a pump to a motor, and can be used horizontally or vertical.

 

[Pooh_Bear]

What I've got is an MTD lawn tractor with a good 20 hp engine and a 46 inch deck and a broken rear axle. I could look for another axle to replace the broken one. But I was thinking, why not make a machine that is more useful. Something a little bigger and that I could put a small FEL on it to load dirt on a trailer.

I was just thinking and dreaming.
Probably just find a good used lawn tractor and buy that.
That's shaping up to be the cheapest of the options.

Pooh Bear

 

[dodge85rc]

An MTD lawn mower will never stand to have a loader put on it. It will break in 1/2.

 

[Pooh_Bear]

That's why I was thinking of building something beefier.

Probably just get a used lawn tractor to mow where the 8N can't
and keep saving for a bigger tractor with a FEL already on it.

I've got another similar mower but it only has a 12.5 hp motor on it.
The 12.5 hp motor is bad. Wonder if the 20 hp motor will fit.
Another thing to add to my to-do list.

Thanks.

Pooh Bear

 

[Kernopelli]

When you say you broke the rear axle, I assume it is the transaxle that is broken? If so, you may want to look at surpluscenter.com they have a number of inexpensive transaxles that may work.