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Discussion Starter · #1 ·
hi, is it possible to run a larger hydraulic cylinder of my eaton 11 hydrostatic drive. like a 2" sylinder with 2' length. what is the pressure of this unit?
I'm going to use it for a dump trailer


Frode
 

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Charge pumps usually only have a flow rate of about 2 gallons per minute at full rpm and a relief pressure setting of about 700 psi. That will take about 10 seconds for a full stroke at full throttle and only 2200 lb of push.

Depending on the geometry of your dump mechanism and the load in the trailer, that may not be enough strength, as well as being slow.

The rise and fall of the oil in the reservoir is a separate issue dependant on the diameter of the cylinder rod, but shouldn't be a concern with a 1" (25 mm) rod.
 

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Ok, lets do the math on this one. A 2" cylinder would work out as follows:

1 (radius of piston for a 2" cylinder) x 3.14(pie) x 700 (pressure) = 2198 lbs of force. It will be slow and I'm not sure that 2200 lbs will work for you.
 

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Discussion Starter · #4 ·
ok. I was hoping for something in the range of 3000 lbs
can I adjust the relief pressure on this unit maybe?
I was thinking of adding a extra tank of oil on the unit to compensate for the cylinder

Frode
 

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ok. I was hoping for something in the range of 3000 lbs
can I adjust the relief pressure on this unit maybe?
I was thinking of adding a extra tank of oil on the unit to compensate for the cylinder

Frode
A 50% increase in relief pressure is not really advisable. The implement lift is not the primary purpose of that pump. It's there to ensure that the main pump has a good supply of oil. The implement lift circuit gets what is left over.

A good power steering pump will do the job for you. I don't know the specs on what you might have available, but over here the General Motors cars and light trucks have an excellent power steering pump that will give you the pressure that you want with a marginally improved speed as a bonus, even at lower throttle settings. A P/S pump with a remote reservoir is best, then you can make a new reservoir with the right capacity.

A separate hydraulic system opens up the way for many options, especially if you go with a larger capacity pump. For your present requirements, 4 gpm actually is a better flow rate and a P/S pump would need to be modified to achieve that flow.

Adding an extra oil tank for your existing set up is also not advisable. The oil level in the extra tank would need to be very close to the same as the level in the primary reservoir with a larger diameter hose between them to prevent the flooding of one and the draining of the other. Starving the pump is not a good thing.
 
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