help converting pto phd to hyd phd

[ak9]

I'm in the process of fabricating a PHD to be mounted on the thumb of my back hoe .The tractor is 45 hp with a 14gpm hyd pump~2500psi. The back hoe is plumbed by a rear remote with 1/2" lines . This project is twofold being that when the phd is not installed my intent is to use the new hyd lines for the new hydraulics on the thumb( as it is now it is mechanical).

Where I could use some help is picking the right hyd. motor?... would this one supply enough... ?
Pump option
7.63 CU IN PTO DRIVE MOTOR
coupler
1-3/8" 6T SPLINED COUPLING 167-02206
attached to this 8" or 12" auger
Valve ? double solenoid plumbed before the(P/T) hoe's valves with A/B supplying the auger ...?
I look forward to yalls opinions
ak9

 

[oldnslo]

A couple of critical questions are:

How much torque does this size auger require for the ground you will be working in?

What Rpm do you want the auger to operate at?

The answers to these will help dictate the motor size required.

Hydraulic motor RPM is figured by this equation: RPM = (231 times GPM) divided by motor displacement in CIR (cubic inches/revolution)

Hydraulic motor torque is calculated by this equation: In lbs torque = (PSI across motor times CIR of motor) divided by 6.28

The motor you have selected would operate at around 400 RPM @ 14 GPM & develop 2400 in-lbs at 2000 PSI pressure differential. Depending on line losses etc. you may not get this 2000 PSI.

 

[J_J]

Here is a larger PTO hyd motor that has more torque and lower rpm.

http://www.surpluscenter.com/Hydrau...ors/9-59-CU-IN-PTO-DRIVE-MOTOR-9-7368-160.axd

If using an auger head, what is the gear ratio in the auger head? If it is geared down, it will provide more torque.

On this motor, you will have to provide a relief at about 2200 psi.

At 14 GPM and 2208, torque is about 3,372 in lbs. Motor speed 337 rpm

The solenoid valve will only provide full speed unless you use the engine to reduce pump speed.

Will you be doing something like below, or direct hyd motor drive?

 

[ak9]

thanks for the responses oldnslo ,JJ.
I've given some more thought to my design for the hyd. /auger build. Most of the soils here are hard/wet clay with a little shale/sand stone . I like the higher torque motor JJ linked to. (what is the "•Case Drain SAE 4 "connected to ?) If I choose to go with this valve:
1 SPOOL 20 GPM PRINCE RD-2575-M4-EDA1 MOTOR VALVE
as the solenoid valve I have might not be Ideal for this application
I am building something like the danuser JJ linked to ...my power head is a 2:1 ratio reduction. Concerning the final rpm of the auger I'm old & slo also so some where @ 100-200rpm would be acceptable with torque@3000 in lbs. it should be good to go ?
ak9

 

[J_J]

The case drain goes directly to tank, no QD.

 

[ak9]

JJ
I'm putting this on a Back hoe and I'm unsure how I'd plumb the case drain in ? What do /does no "QD" mean?

 

[J_J]

You should have nothing to interfere with the drain flow. It could go into a return line if it goes directly to tank with out QD's. You are looking for min to no back pressure.

QD is abbreviation for Quick Disconnect.

 

[Tx Jim]

Don't these type QH diggers utilize quick disconnects?

 

[J_J]

I am sure most all hyd attachments have QD's.

Some large hyd motors don't even have case drains.

The manufacturers that do make them say to run them straight to drain.

Some of my attachments have case drains, and the drain hoses are QD's but a larger size QD than the hose size. If that drain line is not connected, the case pressure will blow the shaft seal.

From the Deere folks:

The tractor case drain circuit must be less than 25 psi to prevent hydraulic motor seal damage.

Another quote.

Seal Failure
High case pressure results in excessive load on the lip of the shaft seal. This causes the seal lip to wear a groove in the shaft, eventually resulting in leakage past the seal. If case pressure exceeds the shaft seal’s design limits, instantaneous failure can occur. The subsequent loss of oil from the case may result in damage through inadequate lubrication.

http://www.hydraulicsupermarket.com/case-drain-filters.html

 

[ak9]

Thanks
for the read JJ .I've been searching for alternatives (high torque low speed w/ agricultural standard spline shaft without the case drain) . The case drain will become problematic for me later on as I know I'll find other uses for "this motor". I'm assuming the design of motors w/case drains is to provide lubrication to the bearings ... mainly for continuous sustained usage? in the article your post linked to it mentioned "venting " the drain ? If I interpreted this right the case drain effluent is small in volume ...Curios has to how small in volume ?could it just drain out to a catch bottle of sorts ? to be then not reused ? IDK?
I do have an available single acting rear remote on my tractor I wondering if this would be a case drain option to route to ?
The Danuser PHDconvert I wondering which Pump they use.. Does not seem to have a case drain?
Well I"M searching for a possible alternative any help?
ak9

 

[J_J]

You could perhaps run the case drain to the remote valve OUT/return port as that is going to tank. Dont run the drain to a hose that can be closed off.

You could put a low pressure hyd gage in the return hose and see what the pressure is.

From your thumb, run a new case drain hose back with the other hoses for the IN and return.

Other attachments you might use can use the same hose .

Yes, you can look for a larger hyd motor with out a case drain line. The larger the displacement the lower the rpm. , but more torque.

 

[oldnslo]

AK9,
I believe Eaton Char-Lynn corp. offers their Low speed high torque motors with a high pressure shaft seal option on some models. This option removes the need for the case drain as long as the return line pressure stays below the shaft seals rated pressure. I believe their 2000, 4000 , 6000 series all have this option.

Other companies probably offer the same feature, I just am not familiar with their product lines.

 

[bdog]

Case drain is no big deal. Just run a third line to your motor that runs to tank. On my auger I have a 1/4" case drain line. You could probably put a QD on it without problems. They are not recommended because if you forget to hook it up it will be a problem but if you need one you need one.

I can't stress enough to get a big motor. In the last three weeks I have augered nearly 9,000 feet of holes and I can assure you there is nothing more frustrating than an undersized motor. If the motor is too small it will not be able to turn the auger and you will have to drill a few inches, come out of the hole to clean the auger, go back in, etc.

Take a look at this website Drill holes fast with Belltec products -- Belltec Industries, Inc. they list their hydraulic augers and the torque specs. I would design yours to meet or exceed what they have with regards to torque or you will be sorry.

 

[J_J]

Here is a large 14 cu in motor with 5850 in lbs of force. It is expensive.

14.9 cu in CHAR-LYNN 104-1042 HYD MOTOR at $537

487 ft lbs

12.5 cu in CHAR-LYNN 109-1110 HYDRAULIC MOTOR at $249

Those Belltec augers, are up n the 2000 ft lbs and rpm lower than 100 rpm. You can bet they ain't cheap.

Just for comparison. http://compare.ebay.com/like/191037942870

 

[ditzel]

ak9 how did this project turn out for you? I'm toying with the idea of making something like this for the fel on my Mahindra.