My FEL is bleeding down

[LD1]

A 2" diameter ram that moves 1/4" will occupy an additional .75 cubic inches inside the cylinder. that same movement inside of a 2.5" diameter cylinder will decrease the volume below the ram by 1.25 cubic inches. so you can only leak .5 cubic inches of oil before the ram can't move anymore, which roughly amount to 1/8" in movement.

That makes no sense.

The ram wont move at all.

Using your numbers, for the ram to collapse 1/4": 1.25 cubic inches of oil needs to leave the base end of the cylinder. But if you only open up 0.5 cubic inches, it aint gonna move at all, cause it never would have begun to move that 1/4" to start with.

You can use smaller numbers down to infinity. It just aint gonna move.

In order for the cylinder rod to collapse 1/4" into the body of the cylinder, that .75 cubic inches of oil HAS TO LEAVE the cylinder. It cannot simply bypass the piston because there IS NO ROOM.

 

[TJP89]

That makes no sense.

The ram wont move at all.

Using your numbers, for the ram to collapse 1/4": 1.25 cubic inches of oil needs to leave the base end of the cylinder. But if you only open up 0.5 cubic inches, it aint gonna move at all, cause it never would have begun to move that 1/4" to start with.

You can use smaller numbers down to infinity. It just aint gonna move.

In order for the cylinder rod to collapse 1/4" into the body of the cylinder, that .75 cubic inches of oil HAS TO LEAVE the cylinder. It cannot simply bypass the piston because there IS NO ROOM.

I don't see why this hard to get, LD1 is right. NATURE ABHORS A VACUUM. Its the principle hydraulics works on. If fluid has to leave the cylinder, either the volume must decrease, or it must be replaced. If neither can happen, nothing moves. Try this. Take a syringe, depress the plunger, place your finger on the narrow end. Pull the plunger back and let go. The plunger will snap back to fill the vacuum. The cylinder on a loader works almost the same way.

 

[arlen4720]

The thread that just keeps giving.....

It seems like 1/2 the people "get it" and half the people don't.
THIS LINK might help the people in the "don't get it" camp.
I've also attached a sketch that I drew awhile back, and actually successfully brought someone over to the "get it" camp.

I still have yet to see anyone of the "don't get it" crowd explain how a 2 inch steel rod can be shoved into a cylinder full of oil without said oil coming out somewhere.

I'll happily debate it for awhile longer, but I will become bored soon with such elementary hydraulics.

 

[k0ua]

The thread that just keeps giving.....

It seems like 1/2 the people "get it" and half the people don't.
THIS LINK might help the people in the "don't get it" camp.
I've also attached a sketch that I drew awhile back, and actually successfully brought someone over to the "get it" camp.

I still have yet to see anyone of the "don't get it" crowd explain how a 2 inch steel rod can be shoved into a cylinder full of oil without said oil coming out somewhere.

I'll happily debate it for awhile longer, but I will become bored soon with such elementary hydraulics.

It is pretty obvious that the extra oil was absorbed into the walls of the cylinder and into the rod correct?

 

[LD1]

I'll happily debate it for awhile longer, but I will become bored soon with such elementary hydraulics.

Ditto.

At least until the next thread where someone perpetuates bad advise and advises cylinder rebuild for drifting front end loader.

 

[TJP89]

It is pretty obvious that the extra oil was absorbed into the walls of the cylinder and into the rod correct?

Of course not, the cylinder rod just underwent spontaneous shrinkage!!!!

 

[Threepoint]

My brain still hurts.

 

[arlen4720]

My brain still hurts.

At least that means you are thinking about it:thumbsup:

 

[RandyT]

That makes no sense.

The ram wont move at all.

Using your numbers, for the ram to collapse 1/4": 1.25 cubic inches of oil needs to leave the base end of the cylinder. But if you only open up 0.5 cubic inches, it aint gonna move at all, cause it never would have begun to move that 1/4" to start with.

You can use smaller numbers down to infinity. It just aint gonna move.

In order for the cylinder rod to collapse 1/4" into the body of the cylinder, that .75 cubic inches of oil HAS TO LEAVE the cylinder. It cannot simply bypass the piston because there IS NO ROOM.

Which basically was the point I was trying to make, if there is equal pressure on both sides of the cylinder seal. If you have lower pressure on one side of the than the other, you can have seepage past the seal to equalize the pressure, but because of the volume displacement would be almost unmeasureable

 

[arlen4720]

Which basically was the point I was trying to make, if there is equal pressure on both sides of the cylinder seal. If you have lower pressure on one side of the than the other, you can have seepage past the seal to equalize the pressure, but because of the volume displacement would be almost unmeasureable

As long as "almost immeasurable" means "zero". The only movement that could happen, would be a result of the steel cylinder stretching and/or the rod seal bulging.