PHD Mod from PTO to Hydraulic - need advice

[J_J]

If you are installing a control valve, it should have relief and a PB port.

The pressure on the 3pt that you read is set up for the 3pt. If you install another valve, you need to set the control valve relief to about 50 to 100 psi below the pumps max pressure.

The 3pt pressure relief can be set equal to the first control valve in the flow path.

 

[dsails380]

Hydraulic oil is not very compressible. Especially at only 1800 PSI. You'll have way less than 1% compression of the fluid.

Very little heat is generated by the pump. The hydraulic motor will heat the system more. Hydraulic motors have efficiency percentages. As a general rule for geroler or duroler motors, use 75%-80%. Spur gear motors will be a little more efficient, around 85%-90%. I'm assuming you have a geroler or duroler motor.

So, if you're providing 4.3 GPM at 1800 PSI to the motor, you are theoretically sending 4.5 horsepower to the motor. You lose the approximately 20% at the motor. That energy is turned into heat (0.9 horsepower of heat generation).

Heat is also generated by restrictions in the system (couplers, hoses, adapters). All of these components have what is referred to as "pressure drop." Pressure drop creates heat as well.

I hope this helps!

Thanks for the explanation, DJNebraska. Based on what you're telling me, 4.5 hp in my opinion isn't worth the expense or headache of doing the conversion. I'd be more apt to pursue it if I had a larger tractor with more flow.

I'll have to get a book on the principals of hydraulics so I can understand the basics better. Glad I have experts like you and JJ to steer me in the right direction.

Thanks for all the help JJ and DJNebraska. I sincerely appreciate it.
Dave K.

 

[J_J]

dsails380,

You can run the auger at any speed up to 99 rpm, and still have the torque. Augers don't need to be fast anyway.

It will depend on the composition of the earth as to what pressure the motor will develop, and therefore the heat. I don't think you will have trouble with heat if you don't force it and let the auger do the work.

4.3 GPM
10 cu in hyd motor
99 rpm

10 GPM
1800 psi
2866 in lbs
238 ft lbs.

 

[Mechanos]

What is your tractor's rated hp at the PTO? If your tractor's implement pump isn't up to the task, you could run a PTO driven hydraulic pump to power the motor for the auger.

 

[J_J]

If he used all of his 18 HP, he could use this pump. 11.4 GPM

Surplus Center - 5.7 CU IN PRINCE HC-PTO-2AC PTO PUMP CI 540 RPM

This one needs 11.9 HP output is 7.1 GPM

Surplus Center - 3.6 CU IN PRINCE HC-PTO-7A PTO PUMP 540 RPM

 

[dsails380]

Hi J.J. and Mechanos.

I like your idea of the Prince 5.7 cu in PTO pump. I have 18.7 hp at the PTO, so this would be an excellent alternative to tapping into the tractor hydraulics, and possibly causing some damage. I also agree the PHD auger should run slow. 99 rpm is more than enough for me.

So if I set up a stand alone hydraulic system for the PHD, I'd use a single DA valve with integral relief, a 4.75 cu in motor and a 5.7 cu in pump? Will I also need a hydraulic reservoir? What size would you recommend?

Thanks guys.
Dave K.

 

[J_J]

Hi J.J. and Mechanos.

I like your idea of the Prince 5.7 cu in PTO pump. I have 18.7 hp at the PTO, so this would be an excellent alternative to tapping into the tractor hydraulics, and possibly causing some damage. I also agree the PHD auger should run slow. 99 rpm is more than enough for me.

So if I set up a stand alone hydraulic system for the PHD, I'd use a single DA valve with integral relief, a 4.75 cu in motor and a 5.7 cu in pump? Will I also need a hydraulic reservoir? What size would you recommend?

Thanks guys.
Dave K.

At least equal to the pump, perhaps 2 times the pump volume.

You might also consider a two spool valve and use the second spool for down pressure.

 

[dsails380]

I found a 10 gallon reservoir, and as I continued looking at the pump specs, I saw a 10 micron filter is needed. I was hopeful that I could mount the valve and reservoir on the PHD, but instead I'll need a small trailer to hold the reservoir, filter, and spool valve. I'll need to do some serious thinking about this modification before I proceed.

I'll be taking off the rose colored glasses now. Thanks.
Dave K.