hydraulic post hole digger

[picanoor]

I want to convert my L7300 phd into a hydraulic one which will hook to my jd5310 fel.
I have a hydraulic motor brand Char-lynn 101 1025-009 with 12-14 gpm flow delivering 650-876inch/lbs torque
Does anybody have an idea if this motor gives enough torque and speed to run the post hole digger? JD deliveres 11gpm but i am working on a PTO pump with 21gpm for an other project so the flow should be ok.
the Motor speed is twice the 540 of the tractor so this doubles my torque?

Thanks for the input.
Pete.

motor details:
2.8 cu in CHAR-LYNN 101-1025 HYD MOTOR
Brand new CHAR-LYNN H series motors. Gerotor power element. Interchangeable with the following motor lines: Dynamic BMPH, Danfoss DH, White RS, Parker/Ross MG/TB.

SPECIFICATIONS

* Disp. 2.8 cu. in. / rev.
* Motor Type Gerotor
* Pressure:
1800 PSI cont.
2400 PSI int.
* Torque:
650 in-lbs. cont.
876 in-lbs. int.
* Speed:
969 RPM cont.
1127 RPM int.



* Flow:
12 GPM cont.
14 GPM int.
* Rotation Reversible
* Mount 2 bolt SAE A
* Shaft 1" dia. x 1-3/4" keyed
* Ports 1/2" NPT
* Case Drain N/A
* Size 5-1/4" x 3-5/16" x 3-5/16"
* Shpg. 13 lbs.

 

[Kernopelli]

Using the motor specs of 12 GMP/1800psi continuous and assuming 65% efficiency of the motor, this equaled 8.6 HP. This was per Baum Hydraulics hydraulic motor calculator. Seems like there should be more factors involved to arrive at this conclusion but I have every reason to believe it's correct.

Hydraulic Motor Calculator

 

[DDT]

FYI, If you put the 21GPM pump on a 15 GPM motor you will blow it out quickly. your tractor at 11 GPM will work fine.
I have a Landpride model 5-12 GPM and works fine on my 9.8 GPM tractor.

 

[Brad_Blazer]

The higher motor speed allows you to double torque IF you add a 1:2 reduction gear. It would be simpler to get a bigger displacement motor if you need more torque and drive the PHD head directly. Pick a displacement that matches the displacement of your PTO pump and you will get a 1:1 output speed. Don't worry about max flow and RPM ratings except as values not to exceed.

 

[picanoor]

ok thanks for the info.
i was not planning on running the pto at full 540 rpm anyhow.
I was just trying to find out if the 700 inchlbs torque is enough to run the phd with the 3:1 original gearbox on it.
Any input on this?

 

[wldrbob]

most direct drive post hole augers use 250 to 350 ft lbs yours would put out at max (700 )175 ft lbs after going through the 3 to 1 reduction . for a 6 in hole i think it would be ok . you might have to lift it out and let it clean a few more times.

 

[jenkinsph]

I would rather use a motor with a higher displacement, something in the 300 to 400 rpm range if using the 3:1 gearing, your auger top speed of about 100 rpm or better is plenty fast enough. From my experience somewhere between 50 and 100 rpm's depending on the bit size is about right. You need the augers to turn fast enough to clean the auger but you need to maintain enough torque to power you through it all.

 

[picanoor]

thanks everybody for all the help and useful information.
I found a bracket that fitted on the digger and on the hydraulic motor.
I used Northern tool 1" and 1 1/4" coupling in one i drilled a 3/8" hole in for the pto connector shaft.
Digger works like a charm on my 5310 which gives about 11gpm.
see pictures, the yellow bracket has some plates which act as counterweight for the hydraulic motor.

 

[questrov]

thanks everybody for all the help and useful information.
I found a bracket that fitted on the digger and on the hydraulic motor.
I used Northern tool 1" and 1 1/4" coupling in one i drilled a 3/8" hole in for the pto connector shaft.
Digger works like a charm on my 5310 which gives about 11gpm.
see pictures, the yellow bracket has some plates which act as counterweight for the hydraulic motor.

Just the info and even better pics and details I was looking for! Any chance you remember where you got the bracket that fits both motor and digger?

 

[buickanddeere]

Double the motor displacement and torque.