Starting Educational Hydraulic / Pump Lab

[profreynoldsuwf]

All,

I have been asked to spec out the equipment necessary to build a small fluid power lab for a mechanical engineering program. I say "fluid power lab" but what was really told to me was "hydraulics/pump lab" but I have interpreted this to mean fluid power. If you believe I am mistaken, please let me know. What I was wondering was this - if you were handed 500k and told to make a decent fluid power lab, what would you buy? I would like to be able to not only teach the basics, but have a platform for some light research. Any ideas? If you have no ideas, do you have a possible referral I can contact?

Thanks for any comments/consideration

 

[hydtools]

Google Parker Hydraulic Training, Bosch Rexroth Hydraulic Training for ideas and training systems. May or may not be suitable for your "light" Hydraulic research.

Ted

 

[profreynoldsuwf]

Thanks for the tip. I was hoping to spec something more general and avoid the canned packages but I do realize that it is an easier solution.

 

[MikeHalloran]

The virtue of the packages is that all the fittings you will need are already there.
Acquiring an inventory of appropriate fittings and adapters to slap together a system at random could get expensive fast.

If I had zero budget, I'd start in a junkyard, and bring home some convertible tops, complete with underlying structure, and an ABS system or two.




Mike Halloran
Pembroke Pines, FL, USA

 

[HPost]

I would suggest that you clarify the requirement first. In the true sense, hydraulics is the study of fluid flow and fluid power is something quite different.

A pump for a hydraulic system could be a low pressure centrifugal pump, or it could be a high pressure axial piston pump. A quick confirmation of the brief could save a great deal of time and potentially, save some embarrassment.

If your brief is to set up a pump lab, as assuming that you really are going to investigate fluid power, I would suggest that you buy as little as possible, instead, try to procure old and worn out pumps. The theory of pump technology can be easily explained in words and pictures, it is only looking at the pumps in detail that will show how they are worn out and damaged by water in oil and other hard and particulate debris in the oil.

In the longer term, if it were my money, I would want to see how the pump degradation affects the performance and economy. Given that power and energy contained in fluid power systems can easily do a great deal of harm to untrained people, it is, to my mind anyway, better to spend the money on getting quality gear that can sample pressure and flow and therefore analogous power and energy at low levels with a scanning frequency. If you can keep the power and energy at low and safe levels, it will allow student to get a more intimate understanding of what is going on.

The relationships between flow, pressure, energy and power...with efficiency gains and losses, apply at all levels and there is nothing to gained from have multiple kilowatts of power in the labs because it is just too dangerous and it becomes prohibitive.

In terms of relative safety...

High flow rate with low pressure = Good

High Pressure and low flow rate = Good

High flow and high pressure = Bad

I could easily spend 500k on good data acquisition and storage with little bit thrown in for procurement of lines fittings and a pump or 2. I would certainly not go to Parker and Bosch Rexroth for a solution.

Those are my thoughts anyway...

Cheers

Adrian

Adrian Wright CEng MIMechE
Engineering Specialist
Hydraulic Systems
Caterpillar (UK) Ltd

 

[profreynoldsuwf]

Adrian,

Thanks so much for your comments. I wish I knew more about what is wanted. I got this from my dean who met with a local company that expressed interest in funding a "hydraulics/pump lab". The message I got was to come up with a proposal for them. We are a new mechanical engineering program (hence I think fluid power) but the company that expressed interest is much more of a civil engineering firm. And our university if getting civil engineering in a few years. There has also been no mention of a proposed dollar amount for this project. I think I am going to try and get a better feel for things. I'm really trying to ask the question "If you had 100k, what would you buy to teach hydraulics and pump systems?" Perhaps that is easier to define. And a follow up "What if you only had 50k"?

 

[profreynoldsuwf]

I got some clarity on this. I was told to "shoot for the moon" and describe a pump lab that would be around 500k. It would teach pumps, hydraulics, and incorporate large pressures and flow rates.

 

[HPost]

Wow, the budget went down pretty quick...

Keep it basic, get a pump, a valve and an actuator. You'll obviously need a motor and some level of motor control, plus some connectors.

The root of what I said before still applies, it needs to be low power so they can get stuck in and really see whats going on.

The fundamental principles are always evident and always apply, the trick is to capture the data. We all know that the basic premise of fluid power is everywhere in nature and any idiot can make a cylinder extend and retract. The real secret is in the control and that is a different story all together.

I would seriously consider hand pumps and plastic valves and actuators to explore the first principles. The fluid dynamics and associated volumetric losses are all going to be there and you can use dyed water to show what going on. Most of what goes on in the inlet of any pump is only up to atmospheric pressure and things can leak pretty well at only slightly higher pressures, so I would certainly look to keep it low pressure.

It is very easy to over do it, but until they have a good understanding of the first principles of fluid power, I wouldn't invest in much more than what you would see in play school or kindergarten, except that is would have some high end data acquisition gear strapped on to capture the important details.

I've designed big, high pressure closed loop systems, with servo control...playing with a water pistol is not much different and it can be much more fun.

Cheers

Adrian

 

[profreynoldsuwf]

Actually once I talked with folks here the budget went up again. I was told to model after Georgia Tech. 500k.

 

[HPost]

Just seen the second comment...that just sounds wasteful to me. Making everything big will not add value. The control we use on modern electro hydraulic systems is about controlling fractions of volumetric flow and just a few Pascals. Shooting for the moon just means that you end up spending half the budget trying to keep the temperature under control.

If the system has too much power, the student wont be able to get near it, they'll make you put it in a cage. The data you capture will just have a few more zeroes at the end...no point there.

Good luck to you...

Cheers

Adrian

 

[profreynoldsuwf]

Thanks for the information. I really appreciate it. I was told to model the lab after something done at Georgia Tech. They use this:

A high pressure, high capacity MTS hydraulic system is distributed throughout the testing bay with modular ports to facilitate quick and flexible testing setup. The main hydraulic pump is a 150 gpm unit with a planned upgrade to 300 gpm. Several smaller pumps, ranging from 21 to 55 gpm capacity also are available for stand-alone testing.

 

[HPost]

From the Georgia Tech website...

Thrusts

The Center's twenty-five research projects and four test beds are clustered into three thrust areas:
Efficiency, led by Dr. Monika Ivantysynova, Purdue University
Compactness, led by Dr. Andrew Alleyne, University of Illinois at Urbana Champaign
Effectiveness, led by Dr. Wayne Book, Georgia Institute of Technology

The three words in bold don't suggest high flow and high pressure

Think low power and high control / instrumentation

for 500K, you could by a Caterpillar Excavator...how would that suit?

 

[profreynoldsuwf]

I agree with you. I think I was looking at the wrong thing. What I posted was for powering hydraulic lifters.

 

[HPost]

Oh well, that would explain the power.

I'm all for power, where it's needed.

If it ain't needed, don't waste it. There is just no need.

 

[hydtools]

I would have a few meetings with the sponsor in order to understand what they have envisioned since they are committing the funds. Then meetings with your dean to find out if the donor's vision matches your institution's mission. Just proposing to spend money on something that meets neither is a waste of time.
Hydraulic fluid power or hydraulic fliud delivery or fluid flow basics in preparation for either.

Ted

 

[MikeHalloran]

We should point out that in the Civil Engineering world, hydraulic engineering is all about rivers and drainage and such, not related to fluid power except for earthmover components and penstocks.

You really need to get aligned with whatever the sponsor is thinking.



Mike Halloran
Pembroke Pines, FL, USA