I have a 2 stage logsplitter pump that I would like to drive a hyd motor with for mowing. Is this feasable? What does the knob on the side of the pump do?

Most logsplitter pumps are hi-lo pumps. Depending on the manufacturer of your pump the specifics of your pump will differ. The knob could be an adjustable pressure relief knob. Do you have any identification tags or stampings on your pump? You would have to match displacements between your pump and the motor you want to drive. In other words you want to make sure you have enough flow from your pump to drive your motor the speed you need.

Well, I picked up 3 of these pumps. Definitly 2 stage pumps because thay are twice as long a regular pump. NONE of them have a data plate. One type has a mounting flange for 4 bolts and the other has no flange. It mounts directly to the face of the pump with 2 bolts. Shafts are only 7/16" in both cases. Log splitter pumps are usually around 11gpm, at low pressure. I wonder if they can be adjusted for different output characteristics?

As BillK replied, the pumps are not 2-Stage but Double Pumps and if for a Log Splitter they are Hi-Lo Pumps that give High Volume at reduced pressure and Low Volume at elevated pressure.

Staging is when a pump has two or more pumping sections of the same volume in one housing. The first pumps Inlet is connected to a tank and pumps the oil to the Inlet of the second pump and so on through all Stages.

Each stage may only be capable of 1,000 PSI working pressure but a two stage pump can have an Outlet working pressure of 2,000 PSI without over stressing the pump units.

Presently the only Staged pumps I know of are used to pump low viscosity liquids, such as water, to high pressure, 5,000 PSI, and still maintain a decesnt efficiency.

Understood Bud. I'm learning. I'm digging up terms from Northern Tool and Haldex catalogs and looking for a visual match. The're calling these log splitter pumps 2-stage or 2-stage hi-low pumps. I've disovered the knobby thing on the side is an unloader valve and is adjustable but I won't mess with it until I discover and thoroughly digest its function

quote:

Originally posted by mason252:
Understood Bud. I'm learning. I'm digging up terms from Northern Tool and Haldex catalogs and looking for a visual match. The're calling these log splitter pumps 2-stage or 2-stage hi-low pumps. I've disovered the knobby thing on the side is an unloader valve and is adjustable but I won't mess with it until I discover and thoroughly digest its function

There's a lot of outlets that refer to them like this but it is an incorrect description. Staged pumps are pumps connected in series, not in parallel as these pumps are.

The unloader valve is there to do just that, to unload one of the pumps. Hi-lo pumps used in log splitters are actually two pumps made into one unit that feed a common outlet the combined flow of the two pumps. When the pressure load against that outlet reaches a certain level then the unloader valve will dump the flow from one of the pumps back to the inlet of that pump, effectively removing that pump from the circuit. The full power of the prime mover can then be utilized by the remaining pump to deliver and increased pressure at reduced flow. In this way a smaller engine can be used with a minimal loss of speed.

I would not recommend starting with a pump selection and then trying to build a mower around it. You should begin by determining what your motor requirements are in terms of speed and torque and then selecting a pump that will provide the required flow and pressure to the motor to achieve that. What exactly are you wanting to do with your circuit, propel the mower, turn the blade or both? What torque and speed do you need from the motor for this?