Recommendations wanted for a Hydraulic Post Hole Digger

[JonM]

my sa20 is intended for a skidsteer but it works just fine on my 6060. the difference is more about speed which im not that concerned with

 

[McMXi]

The pressure is what the auger requires to turn with the flow rate controlled by the valve (simplified). The maximum pressure (I believe) is limited somewhere. You should find that figure in the work shop manual.

The auger requires sufficient flow rate and sufficient pressure, but the required pressure to run is never mentioned in the literature. 4,000 psi at 1 gpm isn't going to do much, just as 100 psi at 20 gpm isn't going to do much. I suppose the assumption is that there's at least 2,500 psi available.

Obviously, the hydraulic oil is there to convert energy generated by the engine to do work i.e. move dirt and rocks. Chemical energy from the fuel is converted via the engine, hydraulic pump, hydraulic motor on the PHD and auger to do work by moving the mass of the dirt or whatever from point A to point B. It's been many years since I took a fluids class, but the hydraulic oil has momentum because it has mass and velocity, and the more pressure, the more mass you can move and at a higher rate, so the faster you can do work.

I always enjoy threads that make me think about things I've forgotten about or never thought about.