Hydraulic Motor questions

[cdhd2001]

I have a JD 2520 with the 46 backhoe. I would like to convert my old pto drive post hole digger to be hydraulic drive and mount it to my backhoe. I have been looking at different hydraulic motors in Northern Tools catalog and decided on a 160-300 rpm low speed high torque motor.

http://www.northerntool.com/shop/too...1047_200321047

I was thinking I could install quick connects on the bucket curl cylinder and use the oem joystick to control the forward, reverse and speed of the motor.

Sound feasible?

Motor specs:

Key Specs

Mounting Type
4 boltShaft Dimensions Diameter x L (in.)
1 x 1 3/4Port Size (in.)
1/2 NPTFDisplacement (cu. in.)
17.9Max. RPM
250Max. PSI
1,600Max. Torque (in.-lbs.)
2,890Max. Flow (GPM)
14Manufacturer Warranty
1 year Limited WarrantyShip Weight
16.0 lbsItem#
1007
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[J_J]

Your link is not any good.

Are you sure the pressure for the motor is only 1600 psi, and if so, I would put one of these across the hyd motor.

Surplus Center - 1/2 NPT 30 GPM 1500-3000 PSI HYD CUSHION VALVE

Holding the speed of the hyd motor will be tricky as you will have to feather for low rpm's, and hold the lever.

Another thing, is that if you use all the pump flow for the hyd motor, you will not have any left for the 3pt. You could put a needle valve in the hyd motor line to the digger, and set the rpm by turning the knob. This will limit the flow to the motor, and let you use the 3pt.

 

[oldnslo]

One concern would be what is the system pressure on your 2520? Is this 2520 the CUT or older Ag tractor?

Might want to look at a unit that is rated for tractors operating pressure.

Check to see what pressure the shaft seal is rated to. Running through QD's and long lines plus the DCV may cause some increased back pressure.

If running a fixed displacement pump you will create heat by feathering the DCV to control speed. May work better to vary engine RPM to control max speed and just use the DCV for feathering when starting and stopping.

Do NOT install a needle valve to control speed unless it has a free reverse flow check built in. If you just install the needle and reverse direction you blow the shaft seal on the motor.

Roy

 

[J_J]

This needle valve should do the job.

Surplus Center - 3/4 NPT 25 GPM PRINCE WNV-1200 NEEDLE VALVE


Your tractor pump only has 5 GPM for implements.

With 17.9 cu in, and 5 GPM, the motor speed will be about 65 rpm