So I know nothing about hydraulics, I'm thankful I just found you guys.

I am an arborist, and a peice of equipment I own I want to add an hydraulic winch too. Right now the machine has a 1gpm pump, which runs a feed wheel, and lift cylinder. The engine on the machine runs at 3000RPM. The winch I want to buy needs 15gpm to run. I figure I need a 2 stage pump, one to run the current system, and 1 to run a whole new system as I don't want to tap into the original system.

I cannot find a pump with 15gpm on one end, and 1 gpm on the other. I am assuming I can get a pump with 15 gpm, and another with more than 1, and just get some kind of valve that limits the flow?

The winch also needs a open center directional control valve.

Can any help me? If you need more info I can supply what I know.

Thanks,

the newb- Brendon

Try a single stage pump with a priority flow control. Get a 16 GPM pump, then set one for 15 and one for 1.

Thanks.

What size tank should I look into for the winch alone? Here is the link to the winch http://www.ramsey.com/industrial/hd-p8000.html .

Priority divider will work, but they operate by throttling the lightest load to force oil to the other side. Need to be careful as to which load operates most of the time.

While operating the 1 gpm load, the 15 gpm will be creating heat at the pressure required by the 1 gpm load.

conversely, when operating the 15 gpm, the 1 gpm will create heat based on the opeating pressure required by the 15 gpm side.

You could use a gear type divider but I doubt there is a 15:1 ratio available without custom.

If you use the 15 gpm load mostly, and the 1 gpm rarely, a priority divider may be easy with minimal heat loaded.

How about a 15 gpm pump with rear A pad and put a second small pump o the back? more money, less heat. Or, a second pump mounted elsewhere?

Basically, the circuit application defines wasted heat and fuel. How much the system gets used defines if the wasted fuel is cheaper than the complexity of adding separate pumps.


descirbe the application more please. which loads at which times, etc.


kcj

The 1gpm would be used mostly, while the 15gpm might not be used at all that day.

Sounds like you require to power units.

So a 2-stage pump will be the best bet?

Does anyone know a good source for 1 stage 1gpm, and the other stage "around" 15gpm. It's a 5/8 shaft, 9 spline, 4.25 (little less) from center to center on the mounting holes.

Is this setup for a machine that will be used for a long time or only for a short lived project?

hopefully up to 15 yrs

If it was for my use for that longevity, I would use a 15 GPM Load Sense Pessure Compensated pump and two, Pump Flow Blocked Center Directional Control valves. The other Ports configured as needed for the actuator functions.

Place a Pressure Compensated Flow Control at the inlet to the 1 GPM Flow Directional Control valve and none at the 15 GPM valve.

Sense each flow line so the pump never goes to pressure until a load on one of the actuators is required.

This will be more expensive up front but will be a trouble free setup and not require a Heat Exchanger even if it runs continuously.

I agree with bud. more complex and more knowledge required, but if it is used often and long time, with energy costs only going up.....

If the 1 gpm is the main load, the priority divider is not the way to go. Basically, 1/16 efficiency all day long. 1 gpm of work, 15 gpm throttled wasted energy.

What you want is a two section pump, not a two stage one. Although the two stage pump is two different gear sets, the flows are combined or unloaded internally, and there are not two separate outlets, only one. Typically a log splitter or trash compactor pump: high flow, low pressure, then low flow, high pressure.

k

Wow, that sounds crazy complex.

Is there a such thing as taking my current pump, and "stacking" it on the back of another pump?

Hey I'm Carl, helping Brendon with his project.

The plan is to go with a 2 section pump, one with a displacement of around 1.2-1.3 in^3 and the other with a displacement around .10 in^3. I didn't think of simply reusing the original pump, but that makes it easier.

His original pump has an SAE A bolt pattern and a 5/8" 9 spline shaft. I haven't found a suitable front section pump yet that doesn't jump to a B mount and a 7/8" shaft.

Bud, that's a great idea. I'm guessing at least $600 for the pump and another $125 for the valve.

For my own knowledge, I'm familiar with presure compensated pumps being ran on a closed center system, however, the chipper is an open center, with a motor control spool (probably two) controlling the infeed and the other spool controlling the lift/crush on the feed wheel.

How does the pressure compensated flow control sense the position of the open center valve(s) that control the infeed and lift/crush? The winch could be fed off a closed center motor spool, so I see how the pump would do its load sensing, but I'm at a loss how it would sense the main side? Also, what would allow both systems to operate at the same time with varying loads and flows? Or am I correct that the systems would need to be operated individually? That's not a deal breaker but it's also not perfect.

I considered running a variable displacement front section for the winch and a piggy back second section for the main system. Manually stroking the variable section would serve as a lockout for the winch when not in use, but I dismissed the idea because a quick search didn't find a suitable pump and I figured it would be quite expensive, and there is a limited amount of room to mount the pump.

My plan to reduce power consumption and more importantly heat was to run a larger dump valve that would cut the flow to the winch's control valve and route it back to tank. There will need to be a dump valve to prevent inadvertant activation of the winch while chipping, so it serves two purposes. I also considered mounting a thermastat controlled raditor (or thermo controlled fan) on the return line.


Thanks for ya'lls help

Carl

quote:

Bud, that's a great idea. I'm guessing at least $600 for the pump and another $125 for the valve.

You may be close but the prices sound a little low to me. Actually I failed to read anything about price and I offered the informatiom with the disclaimer, "If it was my circuit I would use---." Over the years I have sold components for many circuits that was the highest Bid. That is, of course, after explaining the reason for the higher cost which was often, USING LESS ENERGY, MAKING LESS HEAT, and NOT REQUIRING A HEAT EXCHANGER. However, the payback must be spread over some time to make the higher priced components worth it.

"For my own knowledge, I'm familiar with presure compensated pumps being ran on a closed center system, however, the chipper is an open center, with a motor control spool (probably two) controlling the infeed and the other spool controlling the lift/crush on the feed wheel."

The original question had no stipulation on using present equipment only a need to run 1 or 15 GPM.

How does the pressure compensated flow control sense the position of the open center valve(s) that control the infeed and lift/crush? The winch could be fed off a closed center motor spool, so I see how the pump would do its load sensing, but I'm at a loss how it would sense the main side? Also, what would allow both systems to operate at the same time with varying loads and flows? Or am I correct that the systems would need to be operated individually? That's not a deal breaker but it's also not perfect.

As I stated in my first post, a Load Sense pump always uses valves that block pump flow in the neutral position. That means they only go above 150-200 PSI when a Load is Sensed and that Load is only supplied whatever the controls designate. It is one of the lowest Energy Wasting systems available but probably one of the least understood and used due to lack of knowledge.

Bud, that's a great idea. I'm guessing at least $600 for the pump and another $125 for the valve.

For my own knowledge, I'm familiar with presure compensated pumps being ran on a closed center system, however, the chipper is an open center, with a motor control spool (probably two) controlling the infeed and the other spool controlling the lift/crush on the feed wheel.

How does the pressure compensated flow control sense the position of the open center valve(s) that control the infeed and lift/crush? The winch could be fed off a closed center motor spool, so I see how the pump would do its load sensing, but I'm at a loss how it would sense the main side? Also, what would allow both systems to operate at the same time with varying loads and flows? Or am I correct that the systems would need to be operated individually? That's not a deal breaker but it's also not perfect.
Bud, that's a great idea. I'm guessing at least $600 for the pump and another $125 for the valve.

For my own knowledge, I'm familiar with presure compensated pumps being ran on a closed center system, however, the chipper is an open center, with a motor control spool (probably two) controlling the infeed and the other spool controlling the lift/crush on the feed wheel.

How does the pressure compensated flow control sense the position of the open center valve(s) that control the infeed and lift/crush? The winch could be fed off a closed center motor spool, so I see how the pump would do its load sensing, but I'm at a loss how it would sense the main side? Also, what would allow both systems to operate at the same time with varying loads and flows? Or am I correct that the systems would need to be operated individually? That's not a deal breaker but it's also not perfect.

You can see my explanation of Load Sense Pumps in Chapter 8 in the Basic book at this link.
http://www.hydraulicspneumatics.com/200/eBooks/

I understand how the pump works, what I don't understand is this:

"...Place a Pressure Compensated Flow Control at the inlet to the 1 GPM Flow Directional Control valve and none at the 15 GPM valve.

Sense each flow line so the pump never goes to pressure until a load on one of the actuators is required..."

I understand pressure compensating units sense the load of a closed center system, what I don't understand is how to sense the load in an open center system without changing the 2 open center valves that currently direct the current 1gpm.

Also, you skipped the question regarding if I was missing something or if the system you proposed would only operate one circuit (1gpm or 15gpm) at a time. The way I understand it, the pump would differ to the lessor pressure (unless there is some divider you're thinking of) and would run the other circuit at that pressure (plus the extra 150-300psi) as well.


Thanks again for your time.


Carl