Hydraulic drive question

[handirifle]

Here I go thinking again, I usually end up either embarrassed or confused, but here goes.

Have been toying off and on, about building some sort of vehicle to cruise around on, while on the property. My land isn't big or steep, but I do have a few uses for it. Also being thrifty (spelled cheap) I thought I could build one, if and when the pieces showed up real cheap.

It would be a sort of golf cart UTV type of rig, but before anyone suggests, I am not a fan of golf carts themselves, gas or electric. In my opinion, when I'm about to run out of power, it faster and easier to gas up than to charge up. The gas golf carts that start when you hit the gas, I do not like either. Yea I know, I'm picky, but hey, it's my idea.

What came to my mind, last night, and the reason it's posted here, if wondering how efficient a hydraulic drive would be? I could use a 15-20hp engine, to drive a hydraulic pump, and use that to drive the vehicle. Reverse and forward ought to be a simple affair, but what I do not know is what kind of speed I could expect. I suspect the thing would be easily under 1,000lbs and a top speed of 10-15 would be plenty, I just do not want a crawler.

Thoughts?

 

[J_J]

You might be able to use the hyd transmission on the 20 to 25 HP lawn mowers/tractors. If you increase the tire diameter, it will run faster, but will decrease the torque. If you try to make it up from scratch, you will have to look at engine,tires, load, torque, speed, hyd pump,motor, valve, hoses, etc.

.

 

[dfkrug]

I could use a 15-20hp engine, to drive a hydraulic pump, and use that to drive the vehicle. Reverse and forward ought to be a simple affair, but what I do not know is what kind of speed I could expect. I suspect the thing would be easily under 1,000lbs and a top speed of 10-15 would be plenty, I just do not want a crawler.

I agree with JJ, you can use a transaxle from a hydro or gear riding
mower. If you look around, you can often find a free non-op mower
sitting around in your area. Whether or not you go with hyd drive, the
mower transaxles usually have a differential, reverse, and integrated
brake. Surplus Cntr has a bunch of them new, too. This one is only
$79, plus shipping:
https://www.surpluscenter.com/item.asp?item=13-1471&catname=powerTrans

BTW, I recently sold my 12.5hp JD gear riding mower....it was scary-
fast in 5th gear.

 

[AKKAMAAN]

Speed range is a problem with any hydrostatic drive, HSD. HSD loses a lot of efficiency at higher speed, due to increased mechanical friction at high flow on the variable HS pump. To increase speed range you will need a variable HS motor, but the same problem will still be there...... inefficiency....
You will "kill" your engine at 15mph, if you get into any kind of resistance...

I would say that a v-belt drive like an ATV or snowmobile is the best alternativ....home built HSD is an "expensive hobby" at the most....

2c

 

[wdchyd]

I would say that a v-belt drive like an ATV or snowmobile is the best alternativ....home built HSD is an "expensive hobby" at the most....

2c

X 2......Unless you have another HST Donor Vehicle to scavenge the components the build would not be cost effective to fabricate by the seat of your pants......If you did have a donor vehicle of sorts you could set up the hyd drive motor with chain drive so if the speed/torque ratio's aren't good then changing sprockets is cheaper than changing displacements on components......:2cents:

 

[David Devuono]

With two of those transaxles and a 15hp (verticle shaft) you could build a half track? One axle probably won't support much weight. I am building a hydraulic drive with tracks. I should know in a week or two if it will move. Spending about $4500 bucks!

 

[AKKAMAAN]

With two of those transaxles and a 15hp (verticle shaft) you could build a half track? One axle probably won't support much weight. I am building a hydraulic drive with tracks. I should know in a week or two if it will move. Spending about $4500 bucks!

Hope you are having a lot of fun!!:laughing:

 

[handirifle]

With two of those transaxles and a 15hp (verticle shaft) you could build a half track? One axle probably won't support much weight. I am building a hydraulic drive with tracks. I should know in a week or two if it will move. Spending about $4500 bucks!

WOW that is WAY more than I was hoping this idea would run. As usual there's a million things I didn't consider or was aware of. I had thought before of the mower idea, so maybe I'll go back down that road.

Thanks guys for all the good replies.

 

[VroomVroom]

I often thought of the idea as well as many others. I know a little about hydraulics as I studied in school a couple courses. I thought about making a atv similar to david devunos hydraulic dumper. The overall vehicle wouldnt be a problem, but I'm wondering what they have out there now for devices used for drive system. I would need a drive system with enough power to haul maybe 4 200lb men, with tracks in soft ground, top speed on a hard surface of maybe 20 mph. I currently use and have many J5 bombardier tractors, which has the ruggedness and power needed for the work, but the problem is its slow on rocky terrain. This is where the 4 wheel atv excells. But when we get into the peat moss and bog land, with creeks and deep holes, the rubber tires dont cut it like tracks do. So i thought about making a tracked machine to carry 4 men, for nothing more then to carry personal, with a soft suspension for the rocky trails but with the low ground pressure for the bog lands. when We need the heavy work, I can use the J5. But the Hybred tracked machine would go as fast as an atv on the large bouldered trails and as fast or better on the soft spongy bog land, but capable of carrying 4 men. My probably is, I know how tough a drive system needs to be . Transaxles I have little knowledge, but they look too slight. Whats out there that I can use that would take the heavy drive force of 800 or 1000 lbs in rough terrain over boulders. I would be afraid of some drive motors wouldnt be able to handle the lateral loads. Need some advice.

 

[mmurphy]

If you check out "My Tractor Forum" you may find the type of set up you are talking about. I have seen in the past couple of years different track build set ups that do not use hydrostatic drives.