Hydraulic Motors?

[kdlklm]

I have got 4 hydrostatic motors that have a maximum flow rate of 15.9 GPM at 2030 PSI. To get the maximum performance out of them, would I not need a pump that can put out 63.6 GPM. Or am I misunderstanding the principle of how it works. The reason I'm asking is because the pump that was suggested for me to run these motors is 19.6 GPM at 1250 PSI.

 

[J_J]

Do you have hydraulic pumps are just hyd motors?

Do you mean variable speed pumps?

What is the name and model # ?


You would want the pump to match with the flow of the motor.

 

[J_J]

If they are hyd motors, it will depend on the way you connect them, as in series, parallel, or in a series parallel set up.

The Power-Trac machine that a lot of us have , use a series/parallel setup, using a variable speed pump/hydrostatic pump.

The 3000 psi is dropped across two motors in series on one side, and same for the other two motors.

If you install them in series, the flow in GPM will flow through all of them, and the pressure will be divided between the 4 motors.

If you put them in parallel, you will need about 60 GPM to fully run them at their rated RPM, and at their rated pressure to develop the HP needed.

Each of the motors will develop HP based on the GPM and pressure, and displacement.

The torque is based on the displacement in cuin and pressure.

 

[kdlklm]

I have attached the PDF files with all the specs of the pump and motors.

4 Hydro-gear Model HGM-08P
1 hydro-gear model PW

 

[kdlklm]

It appears now that I look closer at the specs, it will be tandem pumps, each pump will run one side of the machine. So each pump has two motors.

 

[J_J]

So you have both hyd motors and hydroatatic pump.

On the zero turn mowers, there is a pump for each motor.

Are you planning on using one pump and 4 motors?

Can you explain your plan on how you want to use the motor and pump combination.

Essentially what you need to do, is to determine the HP that would be required to power what you want to build. If it takes 4 hyd motors that you have, you need to find a pump that will support the demand as to GPM and pressure.

The hydrostatic pumps have their own valves, so connecting the motors to pump should not be a problem. You then need a tank, and filter system.

The engine that will turn the pump has to be selected based on the potential hp that the pump, can develop. If done correctly, you will need a little extra for the electric part of the machine. What size alternator on the engine or external alternator. Battery size, tire diameter and size, etc. What speed do you want?

These are just some of the things to consider when developing a project.

You might get some good ideas by looking at some of the zero turn mower schematic and parts.

My hyd machine needs about 45 HP to power a pump that will service 4 hyd motors, and a 3 GPM steering/lift pump, and another 13 GPM PTO pump.

 

[J_J]

Another thing to consider is, do you design the pump to power the left front and the right rear. If one pump fails, you can still move if you activate the tow valve on the failed pump.

If one pump feeds two motors on the same side, and one pump fails, can you move or can you get home?

Is all this for work or pleasure.

 

[kdlklm]

The design is to have a tandem pump that runs to hydraulic motors on the left side and to hydraulic motors on the right side. I will attach the spec sheet that was ran by hydro-gear for the system design. I plan to be running a 30 hp gas motor, the system will also use articulated steering requiring one hydraulic ram.

Does your machine use a gear pump or a piston pump. I'm thinking about going with piston pumps, they are a lot more expensive, but are supposed to be a lot more efficient.

The wheels will be 22 to 25 inch, and I'm hoping to get 20 to 25 mi./h out of it.

This machine is for pleasure.

 

[kubotakid USA]

Why do you want to run two hydraulic drive pumps? You can run all 4 motors on 1, So much cheaper, an simple ta boot. I have a small 4x4 road grader, Its got a hyd motor on each wheel, and >1< hydrostatic pump.:thumbsup: Eric

 

[kdlklm]

Why do you want to run two hydraulic drive pumps? You can run all 4 motors on 1, So much cheaper, an simple ta boot. I have a small 4x4 road grader, Its got a hyd motor on each wheel, and >1< hydrostatic pump.:thumbsup: Eric

That sounds interesting, would you be able to post some photos of that machine, or even get me the make and model number so I can look it up. Do you know what size of pump that it's running.