CBR Steering Pumps - OEM Applications?

[Provience]

The TC spool valve seems close enough that it might work but the bypass section is narrow enough that I don't think it would.

I did notice a few items of interest. The tc pump has a stiffer spring on the back side of spool valve. Almost twice as stiff and the pilot circuit port is larger.

I think i solve the mystery of the spool valve needle. I noticed this about the CBR:


With the spool valve pushed tight against the output fitting, the head of the needle is below the pilot orifice. This would create a higher velocity at this point, decreasing pressure on the spring side of the spool valve. In effect causing regulated flow to start at a lower flowrate.

I'm starting to wonder if this pump has a higher displacement, but starts regulating flow down at something like 600rpm. IF that were the case and flowrate point of regulating flow could be raise it would see an increase at idle.

Ways that the flow regulation point could be raised:
-Increasing pilot orifice dia
-Increasing Spool valve spring force
-Decreasing needle head dia

It still doesn't fix why the flow isn't getting to the ram but one hurdle at a time.

just based on the likely displacement of the pump, there is probably little or no idle gain without going to the smaller dia pulley. odds are good that it is flow regulated to whatever the system design originally had as the idle flow.

i'd be more inclined to increase the pilot orifice a couple thou, or maybe even a full 64th" and see what happens from there, and then add the smaller dia pulley

 

[MtnYota]

If it’s 0.67cuin I agree. Based on the range radial dynamic posted of 0.67 to 0.95, and the fact that a diesel with hydro boost is about the highest demand stock application, I am hopeful it’s closer to the 0.95. In which case, there would be an increase at idle if I can increase the rpm that the flow regulation starts.

 

[MtnYota]

Huge improvement. I used a stiffer spring and the flowrate at idle increased to 4gpm. The steering feel is much better and lock to lock is much easier and cycles just above 2secs. Pretty much as fast as I can turn the wheel. After a few minutes of warming up the flowrate is about 3.5gpm, but the steering feel and quickness is still the same.

https://www.youtube.com/watch?v=UU23Uk33CD8

https://www.youtube.com/watch?v=7ZlP5N5em8U

 

[AgitatedPancake]

That's great news! So it was the flow control all along, what a strange contraption. And now hearing your flow numbers near idle with a relatively slow pump RPM at idle, I'm really curious what the displacement of that pump you chose actually is. If it's on the larger end of the scale, I'm extremely intrigued. Not that you plan on tearing the pump apart any time soon, but if you do it would be awesome to measure the diameter of the pump components to compare against the TC and CB stuff.

Just for grins, what did the stiffer spring come out of - the PSC pump you mentioned?

 

[Provience]

Huge improvement. I used a stiffer spring and the flowrate at idle increased to 4gpm. The steering feel is much better and lock to lock is much easier and cycles just above 2secs. Pretty much as fast as I can turn the wheel. After a few minutes of warming up the flowrate is about 3.5gpm, but the steering feel and quickness is still the same.

https://www.youtube.com/watch?v=UU23Uk33CD8

https://www.youtube.com/watch?v=7ZlP5N5em8U

whic spring did you change? the main one or for the little inner piston?

 

[MtnYota]

It was the main spring. The new spring was the same dimensions but about 0.010 thicker wire. That results in almost double the spring rate. So I think that any of the three methods I mentioned above would have helped raise the point of flow regulation.

In playing with AP's spreadsheet it seems to follow a 0.95cuin displacement with Flow regulation at 3.5gpm and a 95% regulation efficiency.

On the issue as to why my cycled time wasn't matching 3gpm, I noticed Eaton lists the gpm flow rating open center as 4-8gpm. I need to look into steering valves more but I may not have had enough flow for the valve at 3 gpm.

 

[Provience]

It was the main spring. The new spring was the same dimensions but about 0.010 thicker wire. That results in almost double the spring rate. So I think that any of the three methods I mentioned above would have helped raise the point of flow regulation.

In playing with AP's spreadsheet it seems to follow a 0.95cuin displacement with Flow regulation at 3.5gpm and a 95% regulation efficiency.

On the issue as to why my cycled time wasn't matching 3gpm, I noticed Eaton lists the gpm flow rating open center as 4-8gpm. I need to look into steering valves more but I may not have had enough flow for the valve at 3 gpm.

awesome

makes sense on the vale