Steering logic.

[blackwell]

All regulatory groups require this, OSHA, Automotive (SAE), MSHA, and others. Steering must take priority, does not mean that other functions can't operate at the same time, but steering must work if all others stop.
As stated before, the steering valve only outputs a fixed flow per rev of the steering wheel, reguardless of the flow to the valve. This is done by a gerator element (a pump) that is turned by the steering wheel dumping oil under pressure equal to the displacement of the gerator. On small PT's that is about 7 cubic inches of fluid per rev on the steering wheel. When the engine is not running, thru a series of checks, you can mussle the wheel to pull oil out of the tank and steer the PT with mussle power.
As stated before, the steering valve is in series with the lift valve which allows the steering to take priority, but when not used, all the flow goes to the lift valve thru the power beyond port of the steering valve. The relief valve protects both valves, since it is the first thing in the circuit.

 

[blackwell]

Yes, still have a 2445 and 2460. Total of seven PT's at all locations.
EB

 

[Charlie_Iliff]

<font color="red">The steering circuit is in front of and in series with the lift and tilt valve, and has priority. I believe this is for safety reasons. </font>
Right - that's how it is now. I was talking about what might happen if someone replumbed the two in parallel instead of series. I think then the steering might only work if you were also lifting or curling - and vice versa -- not exactly the effect desired. /forums/images/graemlins/grin.gif

 

[Spiffy]

OK Dead horse alert on me! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

But the last several posts seem to confirm what I was thinking (even if my communication leaves much to be desired compared to Blackwell, Charlie, and Bob). So, unless I'm stuck in an incorrect assumption (still very possible): the Only way this would be effective would be putting a solenoid in to allow the parallel flow only when desired.

 

[Spiffy]

Am I the only one who found humor in the asumption that an eletrical guy might condsider jj to be either imaginary or negative? /forums/images/graemlins/grin.gif If so, my appologies for the lame attempt at humor. /forums/images/graemlins/crazy.gif

 

[J_J]

Parrallel to me means that each branch would have use of the available fluid. At rest, the fluid would go to tank. If sterring is activated, full force would be applied. If driving straight, full force would be available to the lift circuit. If turning and lifting, both would operate, but at a reduced rate.

 

[Spiffy]

You are right about the parallel, but if both are open center, the "open center" is the path of least resitance, then by plumbing in parallel it will actually flow to [and straight through] which ever one isn't being used.

 

[BobRip]

</font><font color="blue" class="small">( You are right about the parallel, but if both are open center, the "open center" is the path of least resitance, then by plumbing in parallel it will actually flow to [and straight through] which ever one isn't being used. )</font>

I agee. This is the point I was try to say with too many words perhaps.

Bob Rip

 

[J_J]

I just looked at my Hydraulic CD, and came to the conclusion that I only need to use a flow divider valve in place of the tee that I had mentioned earlier. This will isolate both circuits and provide fluid to both, steering and lift/tilt. The steering and lift pump on my 1445 is a 1.5 to 3 gal pump.

 

[cqaigy]

<font color="red">steer the PT with mussle power. </font>

I tried this out and did get it to turn a little, but wow it was pretty hard to turn. Maybe if the PT was moving it might have been easier.