Hydraulic Motor from Aux Hydraulics?

[Aquaele]

I have a NH TC29D that has a set of hydraulic remotes in the back. My question is; if I connect a hydraulic motor to these remotes will the lever that was intended to control the cylinder control the speed of the Hydraulic motor as well?

 

[radman1]

Yes and no. The hydraulic control lever was not designed as a variable flow control. In large part it is either on or off. However, if you move the lever just sligtly, a little flow will occur, move it a little more and more flow. However, it is difficult to maintain the same little movement/ flow without a human hand on the lever. It would be best to open the hydraulic control lever fully and then use an external flow control valve. Most CUTs do not have a detent on the hydraulic lever to maintain constant flow. (Common on ag tractors. Variable flow is also common on ag tractors.) Thus you would have to tie back the lever to the open position. If used a lot, the hydraulic fluid could be come too hot.

Flow control could be like the following:

Surplus Center Item Detail

 

[Farmerford]

radman is correct.

In addition, the typical remote valve closes the work ports in neutral. That means the motor will not freewheel because the fluid into and out of the motor is blocked. If the motor is running and you quickly close the valve, the motor tries to stop immediately. If it is turning a load with substantial inertia, that may cause damage to the motor, drive line, the load device, or the hoses. You can solve that problem with a check valve across the work ports, which allows fluid in the motor to circulate through the hoses so it can coast to a stop when the valve is closed, but then you lose the ability to reverse the motor. A port relief valve gives some of the same protection by limiting pressure in the motor circuit when the control valve is closed, but the motor still stops pretty quickly and, usually, with several jerks.

 

[Aquaele]

Thank you both for the prompt and accurate answers, I had thought that it would not work, but a relative of mine insisted it would. You probably saved me a lot of time and money. Thanks again.

 

[kennyd]

Let us know what the motor will be used for...

Rear remotes power hydraulic post hole diggers and hydraulic motors hooked to snowblower chutes all the time-so they can indeed operate hydraulic motors under some circumstances.

 

[dfkrug]

The hydraulic control lever was not designed as a variable flow control.

True enough.

What you DO have to control the flow rate is the engine speed, of course.
That actually works quite well with the remote valve fully open. That is
how I operate my hyd PHD. Too bad the NH tractors do not supply a
detented OEM remote valve. Kioti provides detented valves for the first
remote. Many tractors use aftermarket remote valves....a detented valve
should be chosen, since it is a very valuable option.

 

[Aquaele]

I was thinking of powering a char-lyn motor that would turn a 1/6 Yard cement mixer via a direct drive on the axel of the mixer. If I remember correctly the motor is a 2.2cu in per rev motor. Does this give you enough information? Thanks for the replies. Aquaele

 

[radman1]

I was thinking of powering a char-lyn motor that would turn a 1/6 Yard cement mixer via a direct drive on the axel of the mixer. If I remember correctly the motor is a 2.2cu in per rev motor. Does this give you enough information? Thanks for the replies. Aquaele

You won't be able to put that size of a motor as a direct drive for the mixer. Most CUTs are in the 4-9 gpm range for flow. Even at idle, you would still have 2-5 gpm. That size of motor displacement at 3 gpm will turn about 315 rpm. At 5 gpm about 525 rpm. Way to fast for a cement mixer. If you use a flow control valve, and very little flow, your torque will be so low it probably won't turn the mixer. You will either need a larger displacement motor or use sprockets/pulleys to slow the down the rpm of the mixer.

 

[kennyd]

Yeah, like Radman said, that is just not going to work...

Take a look this SurplusCenter calculator, at 5gpm/2000psi a 2.2 motor will turn 525rpm with 701 in-lbs of torque. I think you are definitely going to need some gearing to turn a cement mixer.

Edit:
There is also some very good calculators at Baum Hydraulics to help figure out pulley sizes if you want to go that route.

 

[dfkrug]

I was thinking of powering a char-lyn motor that would turn a 1/6 Yard cement mixer via a direct drive on the axel of the mixer.

As others have stated, you need a much lower displacement motor if you
are going direct drive. The good news is you do not need a lot of torque
to run the mixer.

I am planning to convert my 3-pt PTO mixer (Mixer80) to hyd drive. It
uses a chain reduction drive, and it is still too fast at idle speed. I want
to be able to go down to 20-30 RPM.

 

[Aquaele]

Thank you all once again for the input, and especially Kennyd for the excelent rescources for tech data. If I get the time to play with it over the winter I will post some pictures.

 

[J_J]

Power-Trac has this cement mixer for one of the smaller PT. I believe the output of the PTO pump is about 8 gpm. It might work for you, small and light weight.They have two sizes. A 4 cu ft, and a 6 cu ft

 

[radman1]

As others have stated, you need a much lower displacement motor if you
are going direct drive.

I think you meant to say he will need a larger displacement motor. Larger displacement will decrease the rpm of the output shaft for the same flow. Larger displacement will also increase the torque.

 

[dfkrug]

I think you meant to say he will need a larger displacement motor. Larger displacement will decrease the rpm of the output shaft for the same flow. Larger displacement will also increase the torque.

You are correct, I stated it backwards. Although generally torque goes
up with displacement, that does not have to be true. And some common
series (Char-Lynn S for example) tend to be lower pressure/lower torque
vs some other series/brands of the same displacement (E.G. White HB).
I am trying to find a deal on a very high torque motor displacing about 8
ci and a moderate torque motor of 8-10ci. The latter for a concrete mixer,
the former for another hyd PHD. Torque output is also based on the
internal design of the motor.

 

[flusher]

Yes and no. The hydraulic control lever was not designed as a variable flow control. In large part it is either on or off. However, if you move the lever just sligtly, a little flow will occur, move it a little more and more flow. However, it is difficult to maintain the same little movement/ flow without a human hand on the lever. It would be best to open the hydraulic control lever fully and then use an external flow control valve. Most CUTs do not have a detent on the hydraulic lever to maintain constant flow. (Common on ag tractors. Variable flow is also common on ag tractors.) Thus you would have to tie back the lever to the open position. If used a lot, the hydraulic fluid could be come too hot.

Flow control could be like the following:

Surplus Center Item Detail

I agree with what you say about flow control.

You can get detent adapters for the usual bang-bang control valves on tractor remotes that will hold the valve in the ON position. I have one for the Diniol valves on my Mahindra 5525

Need to install it one of these days. Plan to eventually get a hydraulic PHD that mounts on the FEL bucket.