Steering logic.

[Spiffy]

I haven't downloaded the manuel yet, but your story may just prove invaluable someday. Thanks, Sedgewood!

Bob, by your definition, afraid "i" plead guilty. /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

If the hour meter lies along R and TBN along i; i'm afraid b>>a [a+bi], in regards to my PT anyway. Of course, all these TBN hours are probably saving many meter hours! /forums/images/graemlins/cool.gif Even if not, it's fun anyway... /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[J_J]

Closed center valves are usually used with varaible displacement pumps, at neutral, there is no flow past the valve. The PT steering and lift pumps are fixed displacement pumps.

 

[J_J]

Check valves in the proper places after the flow divider would work.

 

[J_J]

This is a link to Eatons web site dealing with steering pumps. This is a good description of the system that I believe PT uses in our PT's

http://hydraulics.eaton.com/products/pdfs/C-STOV-MC001-E_part1.pdf



Maybe this will explain everything.

 

[Bob999]

J.J. said: <font color="red"> Check valves in the proper places after the flow divider would work.
</font>

I don't understand how a check valve would solve the problem. The check valve would presumably be installed to allow flow into the circuits--it would presumably prevent backflow. However, as I understand it, backflow is not the problem. Rather I understand the problem to be flow in the path of least resistance and a check valve installed as I understand it would be installed would not stop this flow.

 

[J_J]

Bob, forget the check valves. The flow divider will work to separate the circuit. In an equal flow divider, the amount of fluid through both should be equal to the pump output. The one side going to the steering would have a set amount of fluid governed by the pump output. It will be used by the steering , or go back to tank. The other side will go to lift and tilt, or go back to tank. Say the pump is 6 gpm. each side will get 3 gal of fluid to use or not. I should be able to operate steering at 3 gpm, and lift/tilt at 3 gpm.

I ran my 1445 for about 30 min testing the steering and lift circuits. No steering, full lift/tilt. In a large circle, little steering 50 % , I had average lift. In a very tight circle, 95 % steering, no lockout, lift was very slow. In full turn lockout, no lift.

I have a Davis trencher, that is articulated, and steers by a simple valve. Push left, it turns left. Push right, it turns right.

By the way, the lift and tilt circuits must be in parallel, since they can both operate at the same time. The three spool valve is open center, and fluid is always running through the valve, if the engine is running. Fluid also runs through the steering valve when engine is runing

 

[J_J]

On the matter of steering, does your steering wheel return to center if you let go .

 

[Bob999]

J.J. asked: <font color="red"> On the matter of steering, does your steering wheel return to center if you let go .
</font>

My 1845 does not.

 

[BobRip]

So let me get this straight in the present system you can get upto 10 gallons a minute to steer. With the diverter, you will now have 5 gallons going to each attachment. So when you are steering with this setup the most you will get is 5 gallons. So instead of the steering being slow when you are lifting or tilting it will be slow all of the time. OK /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

Bob Rip

 

[J_J]

No. not really. A larger pump will more than make up the difference of any disparity. The 10 gpm was just a figure for explanation. The pump is actually a 1.5 to 3 gpm Barnes pump to supply the fluid for the steering and lift and tilt, so a 3 gpm to 6 gpm will work fine.

I am so very sorry that I offended your logic, but I have the utmost confidence in my ability to make it happen. So let it rest. OK.