What kind of pump is this one on the picture ?

[MortenHansen]

Hello all fluid pro's !

I have a picture of a hydraulic pump that is used for a
specific application and I need to try to find out what company makes this pump!

Do you by any chance know the manufacturer of the pump on the picture ? Do you know or can you estimate what kind of pump it is (data / specs) ? I dont think its a piston pump, but I am not shure.

In this application two pumps are coupled to a common shaft with splines. Those pumps drive a servo valve in paralell. (This is actually a hydraulic brake in case you wonder why somebody would drive a servovalve straight downstream of the pump. The servovalve applies the load when it is closing).

Here is the picture:

http://www.flyinmiata.com/images/misc_images/rototest/DSCN0238.jpg

Regards
Morten Hansen

 

[unclesyd]

You are looking at a gear pummp. It looks like an Al body. Several years ago I saw a lot of Al body pumps on shrimp boats that were gear coupled to the engine.

 

[kcj]

Now I am curious-is this being used as a brake/dynamometer from the front wheel of the vehicle in background, or is that just coincidental location when picture was taken?

Appears that two pumps are on common shaft, servo valve applies load and oil goes right back to tank. Does this not heat up very rapidly during dyno runs, or is there water to oil heat exchanger cooling not shown?

Any gear pump of similar size and mating SAE flange ports could be adapted.
One larger single pump could do the same thing, but maybe the second pump is another circuit. Are the outputs tied together before going into the servo valve, such that both pumps work as one? Is one pump a fixed load and orifice and the other one a fine tuning orifice loop?

Is the valve a true servo, or a variable pressure relief?

Seeing things outside of my own industries and experience is always an learning experience.

Are you trying to repair this thing, or copy the design to build another one of your own?

kcj

 

[MortenHansen]

Hello KCJ, we are planning to build one for a similar but different application.

Yes, the car in the background is coupled directly to the
pumps via a wheel adapter. The oil is cooled down via some very large oil coolers. The valve is controlled via a sophisticated computer contol system.


Question:
Do you think we can use any type large gearpump for this ?
We are in contact with some Chineese manufactureres that have pumps to a quite low cost compared to European suppliers.

Do you know of any alternative supplier of resonably priced pumps ? (We need to transfer a lot of energu thru the shaft of this pump. Approx 300 BHP per pump or 150 BHP if we use a dual pump setup).

Regards
Morten

 

[kcj]

Do you think we can use any type large gearpump for this ?
I would think so, assuming reasonabl e efficiency. Since you are measuring flow and pressure, increasing leakage through the pum gears as pressure increases means losses you won't measure in your flow meter setup. Although if you have rpm and pressure accurately, you could account for leakage in the calcs.

We are in contact with some Chineese manufactureres that have pumps to a quite low cost compared to European suppliers.
Gear pumps at high pressure does not sound like a place for china copy pumps to me.
where are you located? in US, we have burdens Surplus cCenter in Lincoln Nebraska that sells all sizes of industrial pumps at surplus in small odd lot quantities.

http://www.surpluscenter.com

I think

kcj

 

[MortenHansen]

Hi, we can tolerate leakage as we dont measure the pressure or flow of oil. We do the torque sensing via a strain sensor external to the system mounted on a weight arm.
The rpm of the pump shaft gives the distance per time unit used to calculate power.

Will check out the surpluscenter !
Thanks !!

Regards
Morten

 

[MortenHansen]

Kcj, actually I think I recognized the supplier from one of the surplus listings there. Thanks !!

regars
Morten

 

[EdDanzer]

Morten,
Wouldn’t a wheel torque sensor provide your information more accurately? The system you show will require handling large torque values over a wide enough rpm range that gear and piston motors will not work very well at providing.
If you are interested in obtaining drive cycle torques, both accelerating and decelerating the best choice is to measure between the hub and rim. I’m building a pair of wheel torque sensors for 10 hole truck wheels to measure torque during a garbage truck drive cycle. I had hoped someone could share similar information, but the only thing I found was from a University of Virginia simulation, and their results are very suspect.
The State of Washington has built a brake testing machine for highway trucks using an electric drive, and they are not happy with the results so far.
The pump is probably a Bosch gear pump.

 

[MortenHansen]

Hello EdDanzer, we have looked into the possibility and we think that you might be correct. Using gear or piston pumps are probably not going to work. I have that info from several sources.
We are probably going to cancel the project.

Thank you anyway
Morten

 

[EdDanzer]

Morten,
Could you describe what information you are trying to obtain? One post talked about measuring engine torque at the flywheel. Do you have a budget you must meet?