Hydraulic Layout

A hydraulic, hand or other powered pump, and a pair of shut-off valves if the rams are Single Acting.

If you need synchronization or other operating parameters the above may not be sufficient.

Look at this web site for some ideas:

http://www.enerpac.com/

power pac(motor, pump w/ relief valve, hydraulic control valve & reservoir) With pump with GPM rate to move load in time fame needed and pressure rating to move the load. Control valve large enough to handle the flow. Reservoir large enough to store sufficient volume of oil to expand and retract cylinders plus an excess to dissipate heat build up in the oil. Heat build up will be determine by duty cycle. Electrical controls to turn motor on and off and provide hydraulic directional control.

Flow dividers to keep the stroke on all cylinders uniform.

hose and fittings.

What is the temperature range the equipment will be operating in? If freezing or below heaters or heat tape & low viscosity oil may be needed.

Nothing worse than going to startup a hydraulic system and the oil is so cold it won't flow or flows very slowly.

I reommend 10w40 or 20w50 engine oil in systems that operate in temperture extremes. Does a great job in engines and if you look at oil specs on Vickers or Rexroth sites you will see engine oil is OK.

Does'nt thin like hydraulic oil in the summer heat also, so the circut is much more efficient year round.

Please could you direct me to any Rexroth or Vickers site that advocates what you have suggested?

I have strong doubts that engine oil would be of any use in a hydraulic system:-

1. Engine oil does not contain anti-frothing and is not hi-pressure oil.
2. If it is engine oil for diesels it will be a detergent oil, not good for hydraulics.
3. Variable viscosity oil is also not good for hydraulics.

It would be interesting if you are correct though!

My company recommended a hydraulic oil with a pour point of -60 F or lower for winter.

We also recommended to change to a heavier oil in the summer. Having oil with a consistent viscosity in the operating range will make for more consistent results.

The Lighting Reference Handbook has good information in it. Your hydraulic component supplier should be able to get it for you. My copies were always free.

BeeJ

If you have a Vickers Hydraulic catalog, look on page S9 at the recommendations for Hydraulic Fluids.

This Link should take you to a page on the Eaton web site that also shows their recommendations for using Engine Oil or Automtic Transmission Fluid.

http://hydraulics.eaton.com/products/pdfs/03-401.pdf

The 100mm bore is about 4 inches .look for a discarded garbage trusk with a compactor The rams may be usable and what you are looking for. Sounds like you are building one hell of a log splitter or an auto rim crusher to easily remove the tire

Getting all 12 rams to move simultaneously (depending on if you mean precisely synchronized) is not a trivial problem. It's a can of corn to program a controller to actuate all of them at one time. It is a can of worms to get them to all respond the same way. You did not mention the frequency of movement, but that will further complicate the picture.

I agree with enviro man .... not easy..... path of least resistance and all. OMG my wife just told me shes pregnent......... ok back to the problem. First the pressure required to operate one 100ton hyd. jack, is the same as 10 jacks ... or 50 or 100. Just need more fluid and a higher volume pump. You can take a gallon of fluid and pump it into one jack at 1600psi and lift 100tons oh say ... 10 inches just to pick a number. Now pump that same gallon of fluid at the same 1600psi into 10 jacks tied together and all 10 jack will raise 1 inch.....in theory. In reality if the weight on the jacks is not equal all the fluid would go to the jack with the least amount of weight on it. ie, 1 jack with 9 lbs and 9 jacks with 10 lbs, the jack with 9 lbs will rise while the other stay stationery. Might want to try pressure regulators or computer control actuators.

the rams are for davits. i am currently looking at a dual system hydraulic power pack, I have not a clue if this would be sufficient. what other questions can i ask to recommend what is needed for 3 of these rams to operate at same time off of same pack.

- 180 HP diesel cummins engine

1 system- 35 GPM at 3500 PSI

1 system- 25 GPM at 2000 PSI

if i have 6 hydraulic rams with

rod 100mm

stroke 1.5m

motion complete after 8 seconds-time frame needed

1. Do you mean "rod 100mm" or "Bore 100mm"?
2. Why a dual system and different pressures and flows?
3. Why 3 cylinders together? I would have expected two for davits. Or is it 3 pairs of cylinders?
4. Why have you been tasked with the job of designing something so safety critical! You should leave this one in the hands of a hydraulic design company because, when it's got to work, IT'S GOT TO WORK!

We don't want to guess this one. A few more details please.

There are companies that specialize in moving large, fragile, and/or complicated structures. They must move many hydraulic jacks absolutely simultaneously. Lives and property depend on that, so maybe you should contact them (a google search should net some) for advice. As perviously noted, this should be regarded as a critical application.

Here is another pump that might be what you are looking for.

http://www.dynexhydraulics.com/split.htm