2 stage hyd pump

[Bob B]

Hi all,

Pros or cons on running a 2 stage hydraulic pump for FEL or backhoe on my B6000 ?

Thanks
Bob b

 

[bucktail]

Never done it, so I'll be watching the replies myself. I'm guessing that the controls would be pretty flakey as the pressure went up and down and your pump responded.

 

[2458n]

How are you going to control what you are running. Running a backhoe you usually set it at 540 and go to work. The two speeds would be a mistake plain and simple.

 

[100 td]

What are you trying to achieve, faster cycle time, while you may catch up with faster travel with no load on the sticks, what will you achieve, or will you lose on the lower flow HP cycle?

 

[100 td]

You'll probably get used to it, but having higher speed (let's say double or better) will make it harder to control and more prone to position overshoot, and more erratic when you come off that higher speed. Also when you are working above the lower pressure limit, you will probably limit or slow your travel speed due to lower flow when you just want to work at a moderate rate. Is this conversation because 2 stage Chinese pumps are cheap? Personally I would get a constant flow pump for easy of use and safety, verses increased speed/erratic control at high speed with a two stage pump. YMMV

 

[Dave_eng]

Don't get carried away as your pto HP is limited so it limits the pump and pressure you can drive.

To find the input horsepower requirement for a hydraulic pump,
use this hydraulic pump horsepower formula:

HP = (Flow x Pressure) / 1714

Flow = Gallons Per Minute

Pressure = Pounds per Square Inch

Example: The input horsepower required for a pump that needs to
provide 10 GPM at 2000 psi is:

HP= (10 x 2000) / 1714

Calculated out this gives an input horsepower requirement of
11.67 horsepower. (rounded to the nearest 100th)

From what I see on line for the spec's of a B6,000 pto HP, the pto is rated at 11 hp.

So the first example should be the max in pump spec's you buy.

Also remember with a FEL you need power to move the tractor into a pile of gravel so having a pump which sucks all the engine power to run the hydraulic pump leaves nothing to turn the wheels.

Dave M7040

 

[100 td]

In relation to Dave's post, I don't know what loader or equipment flow rates you require, but a B21 TLB, dedicated tractor/FEL/backhoe combination engine hp and pump flow rate is noted below, your tractor will be different but this just show specs/requirements of a dedicated machine.
[FONT=&quot]Kubota B21 Power:[/FONT]
[FONT=&quot]Engine (gross):[/FONT]
[FONT=&quot]21 hp [15.7 kW] [/FONT]
[FONT=&quot]Engine (net):[/FONT]
[FONT=&quot]19 hp [14.2 kW][/FONT]
[FONT=&quot]Hydraulics:[/FONT]
[FONT=&quot]Type:[/FONT]
[FONT=&quot]open center[/FONT]
[FONT=&quot]Capacity:[/FONT]
[FONT=&quot]7.3 gal [27.6 L] [/FONT]
[FONT=&quot]Pump flow:[/FONT]
[FONT=&quot]7.1 gpm [26.9 lpm] [/FONT]
[FONT=&quot]Total flow:[/FONT]
[FONT=&quot]8.5 gpm [32.2 lpm] [/FONT]
[FONT=&quot]Steering flow:[/FONT]
[FONT=&quot]1.3 gpm [4.9 lpm][/FONT]

 

[Bob B]

Thanks to all that responded to my post.
Bob b