Hydraulic drive question

[dfkrug]

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...

Yes, HSTs that use variable displacement pumps are less efficient than
any gear or belt drive. Because of the narrow speed range, they
are supplemented with speed/torque multiplier gear boxes. That's what
we have in our HST tractors.

Many of these free or cheap riding mower final drives have speed
multiplier gearboxes, too. Using a hyd pump/motor to drive the input
shaft (instead of the mower's belt) of these mower drives is a doable project.

 

[AKKAMAAN]

Yes, HSTs that use variable displacement pumps are less efficient than
any gear or belt drive. Because of the narrow speed range, they
are supplemented with speed/torque multiplier gear boxes. That's what
we have in our HST tractors.

Many of these free or cheap riding mower final drives have speed
multiplier gearboxes, too. Using a hyd pump/motor to drive the input
shaft (instead of the mower's belt) of these mower drives is a doable project.

Agree with you dfkrug.....but where do you find a mower drive for a 4000lbs application?

Hydraulics is a lot of fun, but one have to be realistic about "cost", time and money to not say ingenuity, experience and a very good shop.

A 4 seat HST ATV, on a rocky trail, will for sure travel with three empty seats....passengers will walk faster and safer than riding.....

 

[handirifle]

Agree with you dfkrug.....but where do you find a mower drive for a 4000lbs application?

Hydraulics is a lot of fun, but one have to be realistic about "cost", time and money to not say ingenuity, experience and a very good shop.

A 4 seat HST ATV, on a rocky trail, will for sure travel with three empty seats....passengers will walk faster and safer than riding.....

You're not talking aout MY idea are you? Not at 4,000lbs. I figure mine will be in the 1,000lb or less category.

 

[AKKAMAAN]

You're not talking aout MY idea are you? Not at 4,000lbs. I figure mine will be in the 1,000lb or less category.

No I meant the VroomVroom's comment... BUT i still think it is a waste of money, time and fuel energy...compared to a straight mechanical belt variator solution....

 

[J_J]

Here is a hyd driven machine built by Power-Trac, with 6 wheels with 6 hyd motors, and a 25 HP engine, and 2 VSP transmissions. Scroll down to the bottom half of the page for all the particulars and a video. The cost is rather high, but with some scrounging, and a used engine, might bring the cost way down. 16 MPH. It floats, ;and climbs a 60 degree slope with a 1200 lbs load. What else do you need?

UV Class

 

[David Devuono]

You would need straight rubber tracks for use on rocks. This is why I am building my unit, not much out there that will do what I need. I need something that can dump, plow, carry two and be easy on the back. Even the Argo's with track kits are pretty bumpy. Commercial Carriers have no suspension. For me I don't need speed and needed hydraulics for the plow and dump so going all the way. The cost of build is high, 3 separate spool valves, three hydraulic cylinders, big v-twin motor, oil tank,oil cooler, strainer, filter, two hydraulic motors, three relief valves, one flow divider, one flow controller and a ton of hoses and fittings. Tracks alone had 70 feet of belting and 120 feet of steel and about 480 nuts bolts and washers etc.

I won't squawk much next time I see the cost of a set of tracks. If I had to start again I would look at a half-track. Best possible traction with a much simpler design.
Hitch-A-Track

 

[dfkrug]

Agree with you dfkrug.....but where do you find a mower drive for a 4000lbs application?

Hydraulics is a lot of fun, but one have to be realistic about "cost", time and money to not say ingenuity, experience and a very good shop.

Indeed, none of the mower drives are good for a 4000# machine.

A hyd-drive machine completely from scratch? I would consider buying
plans for something like the CADPlans CADTrack articulated loader. But
that's not tracked, as the OP wants.

However, scrounging for an engine, and maybe a set of used mini-ex or
skidsteer tracks, then buying the hyd drive components surplus.....

 

[VroomVroom]

Well, Like David devouno's dumper, there is nothing out there which would work like I want it to. It doesnt have to be hydraulic at all. Im not sure how a rear end out of a truck would work. the problem with those argos and the like is they are solid, they have no suspension, they tried them here and they dont cut it. The are low to the ground, plastic in most cases and the because of the sold nature they break more axles, blow more tires and ruin more axle bearings then any other atv I know. they wouldnt be much faster the the J5 in fact, I wouldnt say they would be any fast on the rocks because of the solid nature. The J5 works well, but slow on the rocks...so I wanted to build something that had a really soft suspension, but with low ground pressure. They need to make an argo of sorts with bigger wheels, and independent suspensions. The rhinos and such can probaly seat 3 or so, but would like at least 4 and they are wider, longer, same engines, and only the same diameter tires as the 4 wheelers....so they will hang up more. I will post a picture or two in the near future when I get the chance for you guys to take a look. Do you think a rear end truck axle would work on such a machine?

 

[handirifle]

Well, Like David devouno's dumper, there is nothing out there which would work like I want it to. It doesnt have to be hydraulic at all. Im not sure how a rear end out of a truck would work. the problem with those argos and the like is they are solid, they have no suspension, they tried them here and they dont cut it. The are low to the ground, plastic in most cases and the because of the sold nature they break more axles, blow more tires and ruin more axle bearings then any other atv I know. they wouldnt be much faster the the J5 in fact, I wouldnt say they would be any fast on the rocks because of the solid nature. The J5 works well, but slow on the rocks...so I wanted to build something that had a really soft suspension, but with low ground pressure. They need to make an argo of sorts with bigger wheels, and independent suspensions. The rhinos and such can probaly seat 3 or so, but would like at least 4 and they are wider, longer, same engines, and only the same diameter tires as the 4 wheelers....so they will hang up more. I will post a picture or two in the near future when I get the chance for you guys to take a look. Do you think a rear end truck axle would work on such a machine?

For your application, I'd look into an old Jeep, set up for off road only. No need to make it go fast, and you could easily gear it down with an axle swap to say 5:13 ratio or lower. With those gears and in low range there'd be very few places it would not go.

My '01 Wrangler had 4:10's and I took it into places that were almost scarry to me. For your app, I would raise it ONLY if necessary to clear your tires. It already comes higher than all the ATV's out there anyway.

Look for a TJ model, as that's when they went to coil springs in the front, much softer ride, on and off road.

 

[David Devuono]

I'd be looking at one of thoses J5's. Put it on a diet and make up some rubber inserts for the tracks and you would be good on the rocks. You could make a 4 seat cab (I know we had three of us in one. make the cab extend over the tracks.