Articulating 4X4 design

[sawdustdad]

Originally Posted by samckitt

Hadn't got that far into it. But if using ported rears, is that not enough to power the steering?

I think the ported pump is fine, was wondering about the steering gear box--or I guess it's a circular valve...what ever they call the hydraulic device that directs fluid to the steering cylinder.

If anyone knows what the proper term is for the steering "valve" used to actuate the steering hydraulic cylinder.

This is one off a cyclops I think. This would work to actuate the articulating cylinder, right?

[sawdustdad]

So here is what I am thinking about, not to hijack Samckitt's thread, but to elaborate on the ideas.

Sam's articulator uses hydraulic pump and motors since it's got Case axles. Most other articulators I see have the engine hanging out front, over the front axle. The do that to get the power off the backside of the engine (which is actually the "front" of the engine per Kohler). and they drive the rear axle with a U-jointed drive shaft.

I'm thinking about 4wd with an entire hydro axle assembly mounted up front, under the engine, that steers (centrally mounted pivoting arrangement), that is driven by a hydraulic pump/motor arrangement. If the pump were driven off the PTO, then it could be engaged as needed. Steering by power steering cylinder. Would need beefy steering and the front axle would need to pivot left/right (to steer) and up/down to accommodate terrain. Moving a lot of iron in that front axle, though. Could even remove the hydro and drive the axle with the hydraulic motor directly, rather than having a pump, drive a motor, driving a pump, driving a motor, driving the axle...except you lose the trunion/swash plate speed control and have more issues with syncing the two axles...Two hydros could by synched by a flex shaft arrangement that would accommodate the axle movement.

Might be easier just to put a couple hydraulic motors on each of the existing two front wheels...?? Open to thoughts...

[cooperino]

Originally Posted by sawdustdad

I think the ported pump is fine, was wondering about the steering gear box--or I guess it's a circular valve...what ever they call the hydraulic device that directs fluid to the steering cylinder.

If anyone knows what the proper term is for the steering "valve" used to actuate the steering hydraulic cylinder.

This is one off a cyclops I think. This would work to actuate the articulating cylinder, right?

As far as I know "I have replaced a bunch of these" called a steer motor or steer valve. I would think anything articulating would use 2 cylinders. The valve on most wheel loaders have 4 ports. I would think a system with one cylinder would use just 2 ports. The steer valves are easy enough to come by. US made ones run 250$ and up. I have gotten china ones for around 100$

[IHinIN]

They’re also called Orbital Valves.

[Alvy]

Originally Posted by IHinIN

They’re also called Orbital Valves.

X2, orbital valve

I like your ideas Frank. Have you done any rpm calculations to see if the hydraulic motors hooked directly will be fast enough?

[sawdustdad]

Originally Posted by Alvy

X2, orbital valve

I like your ideas Frank. Have you done any rpm calculations to see if the hydraulic motors hooked directly will be fast enough?

Yes, back of the envelope. I've looked at a 11 gpm pump driving a matching motor, per the formulas provided by the mfg, it's almost a 1:1 drive ratio--the speed of the motor basically matches the speed of the pump, if directly connected.

Orbital valve. I thought I had read that somewhere, but was thinking circular valve.

My one concern with the rear axle up front steering, is clearance for the tires when steering. Might need spacers to widen the tread. Or live with a larger steering radius.

[Oak]

Go look at some Steiner machines. They use one cylinder for the steering and like Sam's design they have a motor on each axle. The motors are plumbed in series.
DSCN0947.jpg DSCN0950.jpg