Hydraulic pump as a brake

[THERMIK]

Hello Gents,

I would like to build a test station that simulate a load acting an an auger (auger for drilling holes in a soil).
The test station will be build of an auger with a motor and system that simulate a load coming from a resistance when an auger drill into soil.
My first idea was to mount at the end of the auger shaft a hydraulic pump. A pump will charge a shaft with a constant increasing load (as in real: when auger go deeper into soil then shaft is more loaded).
What do you think about the idea?
What kind of hydraulic pump do you recommend to use?
What about other hydraulic components in hydraulic system, relieve valves etc.?

Thank you in advance.

 

[HPost]

Yes, you could use a pump to act as a break. You could also use an induction motor with a bank of resistors. In fact, there are many ways to absorb the energy from the auger. The first decision you have to make is how to handle the energy.

If you don't use it, then it will turn into heat that you have to get rid of.

How much energy are your expecting to have to dissipate?

Whether you use some break resistors, or a pump with a relief valve, the unused energy will turn into heat.

Pump wise, you can use any...gear, vane or piston, even centrifugal.

How much energy (power) are you expecting to get out of the auger?

 

[LittleInch]

Agree, I think you will have a lot of issues to solve which the induction motor / generator has already solved...

See

http://www.islandcomponents.com/Precision-Brakes.aspx

for typical options which are probably more controllable, cheaper and don't have issues with temperature rise, pipes, cooling control valves etc

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ScottyUK]

A regenerative drive is your ideal because it returns the majority of the braking power it absorbs back into the electrical supply, so you aren't literally burning up money as heat. A regen drive is a little more expensive than a standard VFD but not massively so. If this is for a production test rig rather than a prototype or one-off then the energy savings would likely justify the additional capital outlay, plus you don't need to spend money on a substantial braking resistor and the means to exhaust the waste heat to the outside world.

 

[Artisi]

Of course the OP didn't specify how many / how long each test was to be, 1 a day, 10 a day or 1 a month - will make a big difference in how to build, design, and select equipment.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[ashtree]

The OP may be confident/capable/qualified with hydraulics and not with electrics and that might be why he/she has suggestted that idea.

Everything you have said is true but the question was about hydraulics.
I don't have specialist knowledge in the area but in a general sense i can't see why it can't be made to work.Energy dissipation will obviously be a major issue.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[hydtools]

The amount of energy to dissipate will not be greater than that put in. A water/oil cooler will work well. An air/oil cooler will work, but would be larger. Controlling the temperature will reduce viscosity change with temperature. An adjustable relief valve will load the pump. Measuring pump pressure and flow will allow you to calculate energy, if you want.

And NO a large reservoir will not control temperature. Just in case somebody would ask.

Ted

 

[THERMIK]

Auger parameters are following: 5000 Nm, 165 rpm, 90 kW. 1-2 h of continuous test. 20%, 40%, 60%, 80% of maximum power.
Yes, I can build a hydraulic system with cooler.

I will start the investigation with hydraulic system. Electrical system will be suspend at this time.

 

[EdStainless]

Thermik, Basically you are building a dynamometer. Do a bit of research on commercially available ones. At this speed a gear pump might be a very good option.
What drives the auger? You could use one of those....

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P.E. Metallurgy, Plymouth Tube

 

[THERMIK]

Auger is driven by a hydraulic motor. But the purpose of the test is to test whole system with a hydraulic motor as well.

 

[EdStainless]

But you now know exactly what size of hydraulic motor to use for loading it.
I presume that you will measure torque with a cell, and speed.
The motor (being used as a pump), a tank, control valve, and heat exchanger and you should be set.

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P.E. Metallurgy, Plymouth Tube