Full hydraulic machine

[IanPNG]

At lunch today my coworkers and I were chatting about making a full hydraulic 6x6 and bypassing the T-20. Anyone ever done this? Our hydraulic mechanic/fabricator figures it would be fairly simple, just put a smallish pump on the gas motor, couple of drive motors and run some lines and valves.

If anyone has tried I'd like to know the results. I'm thinking it could be a fun project some day.

[Bazooo guy]

And an oil tank,filter and cooler.
The pump would need to be at least 20 gpm if you use 2 motors @ 10 gpm each.

[jerseybigfoot]

At lunch today my coworkers and I were chatting about making a full hydraulic 6x6 and bypassing the T-20. Anyone ever done this? Our hydraulic mechanic/fabricator figures it would be fairly simple, just put a smallish pump on the gas motor, couple of drive motors and run some lines and valves.

If anyone has tried I'd like to know the results. I'm thinking it could be a fun project some day.

you are going to build anything as efficient and weight and cost effective as a t-20

There are lots of threads on the subject. As of yet no successes . The only advantage is instant reverse and counter rotation. The t-20 will counter rotate with a split shift but is not instant.

[Trackster]

I would start by looking at some of the full hydro machines you can buy like the terratrack the old tracksters and a couple of the machines that the builders are interviewed in the VIP section.

I agree about the efficiency but if he is doing oilfield work there may be advantages with reliability that you could give up some efficiency for? Not sure about that but he may be thinking about it because of problems he's having.

Nick

[kunzmm137]

Hydraulic machines are typically slower, heavier, and require larger HP engines than a mechanical drive. Maintenance would be minimal, depending on the final drive design. An oil cooler would be needed, heat thins and breaks down the fluid, and can hurt pumps and motors quickly. A hydraulic machine will give a great amount of control, and almost instant torque.

There are advantages and disadvantages to any design, you need to choose based on your needs.

[rednine11]

My LTV KID is Hydrostatic drive. If you want I can take some pics and send you.
It works REAL good. The thing is a tank.

[Bazooo guy]

Can you post some pics if the LTV KID hydraulics.
What size engine is driving the pump?
And what type of pump is used?
Is it setup to counter rotate?

Edit: I checked out the manual and see its a vickers hydrostatic trans.

[mudslinger]

It's already been done, it's called a MuddOx, see it at MuddOx.net.

[rednine11]

The LTV KID uses a Wisconsin 4 cylinder engine and huge vickers drive units.
The mud ox is set up the same way. both machines will zero turn

[rednine11]

Here is the setup in the KID

[chris davison]

I see a lot of chains for being fully hydraulic. if you want a fast powerful fully hydraulic machine You need a big motor and a variable displacement pump with big displacement wheel motors.

[amphibious drew]

I have never looked into a Kid, but the Mud-Ox runs a hydraulic pump on each side of the machine to the chains. So the hydro's act like a transmission and the chain is the final drive. You could do a pump at each wheel, but there would be very little benefit gained and you would ad a lot of weight doing it that way. Not to mention the power it would take to run 6 more hydraulic motors.

[chris davison]

A setup like this would use 6 wheel motors but they would be hosed in series say one 40 gpm pump with a flow divider. Or if you had a tracked vehicle 2 wheel motors 20 gpm each with a dcv and flow control on each. Leave the motor at 2000 rpm and just move the lever on the pump to go from 0 flow to 40 gpm flow for your speed control. To turn move the flow control for each side if one side is getting 20 gpm and the other 10 gpm its gonna turn. O turn move your dcv in opposit directions.( hopefully not at 2000 engine rpm)

[Trackster]

Or you could skip the chains, drive one wheel and run tracks. That is basically what all dedicated tracked vehicles do.

[chris davison]

I still think they have at least one final drive chain to each side. Besides we were talking about how to build a fully hyd. vehicle If I was going to build a tracked vehicle I would use a v6 an automatic trans to a car rearend mounted high in the rear go thru the hull to drive the tracks and just use brakes to steer with. No chains no hydraulics.