New to Hydralulics - Dump trailer question

[TwinWillows]

Here's the situation: I have a NHTC40DA w/3 added sets of NH rear remotes. 2 sets are used for the top & tilt leaving one set unused.

Due to the large amounts of material we handle on the farm I'm strongly thinking about getting or making a trailer that can be dumped hydraulically. Several of the dump setups I've seen use 1 hydrauilc culinder w/1 hose. I presume these work by aplying hydraulic fluid behind the cylinder to extend it to dump when the control lever is pulled.

The question I have is how does the cylinder retract to allow the dump bed to lower? Do you push the lever in the opposite direction as to dump? Or is there some other sort of hydraulic control valve (?) needed to somehow allow the fluid to get back into the tractor reservoir??

 

[Bedlam]

Im sure someone will tell you how to set up the plumbing , for a single action piston. But its similiar to a pick-up plow valve. The valve applies pressure to the cylinder, thus extending it. Then when you move the lever to drop the dump, the valve opens and allows the oil to return to the resevour.
I have never had to set up a single acting piston on a tractor, so I shouldnt advise you.You might perhaps have to have a seperate valve that would have a low pressure return line to the resivoir.
Sorry I wasn't much help here.
You might call or email the surlus center, I have been treated good by them, and Ive emailed questions and got good results.
Al

 

[Bedlam]

http://www.surpluscenter.com/sort.asp?UID=2004092217421327&catname=powerTrans&keyword=PRWS

 

[MadReferee]

My CountryMfg dump wagon uses a standard ag 24" stroke double acting tie rod cylinder. I bought a Chief brand from Surplus Center. I don't think you want a single acting cylinder for this type of application and if you use a SA cylinder you will most likely need a SA spool.

To dump simply activate the spool. To retract simply activate the spool in the other direction. No muss, no fuss, no hassle.

 

[Soundguy]

Madref.. you really sure about that?

The last .. few batwing mowers i looked at, at the NH dealer had only SA cylinders on them.. 2 sa cylinders running off a single "T" line that runs to one remote... allowing you to fold up the wings.. and you use forward/float to let it gravity down... same with the tailwheel cyl... power to it lifts mower.. release forward and it lowers by gravity... The NH owners manual has detailed pics in the manual on how to operate the tractor OEM supplied remotes.. or at least my 7610s manual does.. covers 5610, 6610, and 7610.. etc... unless I am completely misunderstanding the situation.. etc..

Soundguy

 

[BarryinMN]

I have a single acting dump trailer. It works fine with standard 2 way valves. You won't need anything special.

One caveat however in that the single ram fills & empties. A large ram takes a lot of oil. My JD A Power Trol only has a 4 quart capacity & a full load on the trailer 6K + lbs will not allow the ram to extend fully.

A 2 way cylinder will have oil on both sides effectively adding oil capacity.

I have converted smaller 2 way cylinders to 1 way by installing a breather in the unneeded cylinder port. About a $5 part that eliminates second hose, connector etc.

Pix of rockpicker with breathers, setup has 2 circuits and a valve with only 2 hoses to tractor. /forums/images/graemlins/grin.gif

 

[MadReferee]

Soundguy,

I guess I never thought it thru. In your case float is the key since in the float position both work ports are connected to tank. With a double acting spool with only 1 hose connected to the SA cylinder, putting the lever in the opposite direction from raising will connect the hose work port to tank and gravity will force fluid out the cylinder and to tank.

I guess it pays to think before typing.

 

[1948berg]

On Massey Fergusons there is a valve you have to close to use a dump trailer with a one hose hydraulic cylinder on the extra hydraulic double acting connetions. Another way to do it is to stop the engine and open the lift valve and let the oil return the way it came.

 

[gates]

TwinWillows,
Are the SCV outlets facory or are they afternmarket. Some of the aftermarket add-on SCV set ups will not work with SA cylinders. They have to be ordered accordingly. They take a different internal cartridge to allow the oil to flow in both directions.

Ron

 

[rambler]

Most spools will work a single acting cylinder.

Some work great.

Some there is a little thumb screw to change between double & single acting.

Others work, but you are pushing oil through the bypass valve as you hold the valve to lower the implement. It still pumps oil through the unused port, & must bypass through the bypass, or relief, valve. Works ok.

Oil volume is a real issue. Some big massive single acting cylinders can use a couple gallons of fluid. In a double acting cylinder, once it is full of oil, the volume only changes by the displacement of the rod. On a single acting, the whole thing fills, then empties.

Now for the safety aspect no one mentioned. If your hinge on the trailer is close to the axle, and there is a lot of overhang of the back of your trailer, you can have a problem with a single acting. There is _nothing_ holding the front of the trailer down with a single acting. Only gravity. If you get a lot of weight on the rear overhang of your box (drive something on it, or while dumping the front goes empty, lot of weight on the back) your dump box will slam down all the way tot he ground, full dump.

A double acting cylinder will hold it's position at all times in both directions.

--->Paul