Hydro Lift Cyl.

[MalMac 1,331]

Ok all Hydraulic exsperts, Was thinking or wondering if you can tap into a Eaton 1100 to run hydro lines back to a lift cyl. on a dump trailer and still use the same lift valve.. I am leaving this to all you hydraulic guys and gals out there, because I am not all that fa miler with the workings of the Eaton or Sunstrand for that matter.

[wallfish 17,084]

I'm no hydraulics expert but they do make a selector valve which will connect 2 circuits to one valve. Installed after the valve, it will allow you to select which circuit to operate. By installing quick couplers to the trailer circuit, this would allow you to easily disconnect the hoses to the trailer when not in use.

You may be able to find a smaller one but this is what I'm referring to.

  http://www.surpluscenter.com/Hydraulics/Hydraulic-Valves/Selector-Valves/1-2-NPT-20-GPM-DOUBLE-SELECTOR-VALVE-9-4128.axd

 

 

Quick couplers

http://www.surpluscenter.com/Hydraulics/Hydraulic-Adapters-Fittings/Hydraulic-Quick-Couplers/Quick-Coupler-Pairs/

 

I'm just not sure if the trans reservoir handles enough fluid to add a larger cylinder for the trailer dump.

[MalMac 1,331]

I was wondering the same thing, on if there is enough fluid. After the lines, and cylinder was filled would that make a difference. It also might depend on whether the cylinder was double acting or just single. Not knowing a whole lot about it. Seems double acting would not require anymore fluid once filled. Like said I may not know what in the heck I am talking about.

[wallfish 17,084]

You are close but a double acting cylinder will change the amount of fluid by the volume of space taken up by the rod. The opposite side of the rod end will use a larger volume of fluid because there is no rod taking up that volume of space inside the cylinder. If you do the math to figure out the volume of the rod you plan to use, that will give you the volume of fluid difference when the cylinder is completely closed and completely extended. There are many charts and calculators on the net to use for this which make it simple to change the sizes. This should help calculate what size you can safely use.

 

If I were to guess, the trans should be able to handle a 1" rod cylinder but will depend on the length. The shorter the better but you give up some mechanical advantage because the rod will need to be connected closer to the pivot point in order to make a full dump cycle. Guess it depends on how much force you need for what you plan to use it for. 

[bmsgaffer 2,045]

Personally as much flexing as a trailer would do at the joint, and the constant connecting and disconnecting... I would go with an electric linear actuator. You can make it easy to attach and detach and don't have to worry about fluid levels or activating it accidentally when its not plugged in.

 

And its a lot less messy. All you would need is to wire it to the battery (with a fuse) and a three position switch.

[Madcat 9]

I've done this and it works great. Modified 520H Eaton by adding 4-way selector valve, cylinder and plumbing to provide a 2 point hitch.  Modified C120 Sunstrand to

build a dump truck with hydraulic lift by adding a spool valve and cylinder and plumbing in series with existing valve and cylinder. The dump truck hydraulics are fast acting

and show no affect on the operation of the transmission or existing mid mount cylinder. The truck is not complete, due to darn cold weather and it's buried in snow outside. 

 

[wallfish 17,084]

By adding a second valve, you could use the power beyond port. Instead of sending the fluid back to the reservoir, it will continue on to operate your existing valve. 

http://www.surpluscenter.com/Hydraulics/Hydraulic-Valves/Directional-Control-Valves/1-SPOOL-8-GPM-PRINCE-MB11B5C1-DA-VALVE-9-7861.axd

you would need to order the P-beyond / closed center plug. Should show up in the upper right on the page posted.

[MalMac 1,331]

Alright I'll ask, what and where is hne power beyon port.

[wallfish 17,084]

Power beyond port is just another port on the valve to send fluid to a second circuit. Normally your return line would not be under high pressure but this port will allow you to connect it to a second valve.

 

http://www.insidersecretstohydraulics.com/power-beyond.html

[MalMac 1,331]

I kinda thought that but needed it confirmed by someone who knows. Just need to figure what size of cylinder to use. Needs to by able to lift 1500lbs. I have to do some measurements to check on the length and throw. Still don't know if single action or double. Single will work fine, as the weight of the bed will bring it down. It's a 4 wheeled wagon with a dump bed.

[bmsgaffer 2,045]

I kinda thought that but needed it confirmed by someone who knows. Just need to figure what size of cylinder to use. Needs to by able to lift 1500lbs. I have to do some measurements to check on the length and throw. Still don't know if single action or double. Single will work fine, as the weight of the bed will bring it down. It's a 4 wheeled wagon with a dump bed.

 

I'm going to preface this by saying I am NOT a hydraulics expert, and its kinda just a brain dump, but here it goes:

 

The tractor can only output 700psi, so you need to make sure that your hydraulic cylinder has more than 2 square inches of piston surface. Is the pivot at the very back of the dump cart? I am assuming so because of the back wheels. If you could pivot the load closer to the center you wouldn't have to lift all 1500lbs due to mechanical advantage.

 

I don't think the small amount of oil in the system could push a piston as long as you would need to dump a cart without draining itself completely out. If you put the ram right at the front edge of the wagon you will probably have to lift several feet to dump.

 

Thinking out loud though, you could use a large double acting cylinder and attach it closer to the back. It would not have to lift as high, but will have to lift 2 to 3 times the weight in the cart.

 

I would definitely go with double acting because at least the back side of the cylinder will hold some extra oil when its down. If you did single acting, there is a chance you would drain the transmission completely while extending.

[wallfish 17,084]

Oh, the beauty of the net! It makes the math stuff like this so much easier.

http://knighthawksupply.com/calccylforce1.htm

 

a 2" cylinder will push over 2000 lbs using 700 psi.

[MalMac 1,331]

Gona have to do dome thinking on this. Right now there is a bottle jack lifting it. There is some mechanical lifting in there so the jack only has to extend about 5 inches worth. Going have to plan this one out.

[bmsgaffer 2,045]

Oh, the beauty of the net! It makes the math stuff like this so much easier.

http://knighthawksupply.com/calccylforce1.htm

 

a 2" cylinder will push over 2000 lbs using 700 psi.

 

Aha! The net IS wonderful. So a 2 in cylinder would be more than Now our only other concern with this is the volume of fluid that will be required to lift the cylinder to the appropriate height and comparing that with the available fluid in the transmission (especially when the onboard lift cylinder is extended too).

 

Also have to make sure that when all the cylinders are retracted that you don't flood the transmission.

[MalMac 1,331]

Well in theory and a perfect world and correct me if I am wrong here. Once the oil lines are filled and the cylinder is filled, using a double acting cylinder. The only oil that would be changing the level of the transmission would be the volume of the what the ram/push rod itself would take up. With that said, with the cylinder pulled all the way in and the transmission oil at the full mark, Then when it's extended it would be low. Staring to sound like too much a risk and a big headache to boot.

[bmsgaffer 2,045]

So I used that page that John listed above and google unit conversion and came up with this:

 

As an example using a 2" bore ram with 1.125" rod and 6" stroke (you would have to mount this towards the back of the cart but it can lift 2100+lbs @ 700psi):

 

Volume of oil needed when retracted: 0.223124 US quarts

Volume of oil needed when extended: 0.326399 US quarts

 

so you will need to add an extra 1/4 quart of oil (plus hydraulic lines) to fill the system and the level of oil will drop by 0.11 quarts when fully extended.

 

The eaton 11 holds 5 quarts of oil, so my first guess is to say that this should be no problem at all. But I could be totally off base

[MalMac 1,331]

Very interesting calculations. An extra 1/4 quart added maybe too much. I know the Eaton's do not like to over filled. On the other side If you don't add, will that drop the oil level down too much and cause damage. Defiantly getting into a area I do not know anything about.

[bmsgaffer 2,045]

Very interesting calculations. An extra 1/4 quart added maybe too much. I know the Eaton's do not like to over filled. On the other side If you don't add, will that drop the oil level down too much and cause damage. Defiantly getting into a area I do not know anything about.

 

The extra 1/4 quart would have to be added just to fill the system the first time.

 

How I see it happening:

1. Install and plumb all hydraulic lines valves and cylinder.
2. Make sure your eaton is at the full mark, not above
3. Run system, engaging new valve and cylinder in both directions causing them to fill with hydraulic oil
4. shut down system with all cylinders in retracted position
5. Oil level should be now about 1/4 quart low since it filled the lines and cylinder
6. top up oil level to be "full"

Then whenever you run the system your oil level will drop a little when extending but will never over fill. The oil stays in the new cylinder and lines.

 

There may be something about purging the system of air that I dont know about, so dont try what I said without talking to a more knowledgeable person first.

 

I personally hate the idea of dis-connectable hydro lines. I have them on a Toro Dingo and they are just a filthy mess and hard to deal with, so I would still choose electric for the dump cart even though hydro would be stronger and faster.

[wallfish 17,084]

Quick calculation

A 1 1/8" rod with a stroke of 8" = 7.9 cubic inches 

7.9in³ - US gal lqd =  0.27 US pt lqd

Just a tad more than 1/4 of a pint would be the total volume of fluid change using this size. Less with a smaller rod or less stroke. To put it in perspective, it's 1/2 of one of those little milk cartons we all drank in grade school.

I don't know the amount of fluid the hydro trans uses or the area measurements of the transmission it fills but I would guess that .25 of a pint might only adjust the fluid level on the dipstick 1/8" or less. That's another math question for the net to figure out if you get those area numbers. The existing lift cylinder volume is hardly any concern, since it's so small, but should be added to the total once all the actual numbers are determined.

 

It would certainly be much easier and possibly less expensive to go with an electric actuator. You will sacrifice power and speed but much less complicated. Now you need an electrical guru to make sure your tractor's electrical charging system can handle the load of it.

 

  I built a tilt bed which was 3' x 5' and used an actuator to power it. The pivot point of the bed was close to the center so lifting the bed when full took less power to lift it. This set up would dump a full 3'W x 5'L x 15"D load of dirt and rocks with no problem at all. More strain when completely down and starting the lift but once it moved a little, was good to go. 

http://myoldmachine.com/topic/81-tilt-bed-ariens-tractor/

That little 1/2" rod you can see was changed to 3/4"