Adding Valve to Closed Center Post Pounder

[RickB]

Everyone is overlooking the fact that a Shaver post driver creates a low volume intermittent demand. The lift cylinder is on the order of maybe two and a half inches in diameter. There is no high volume demand and no continuous demand.

 

[Zebrafive]

Tank ? Where is this tank ? Is this the tank ahead of the tractor radiator, under the hood and above the front pump ? I don稚 recall of any mention of a ported transmission filter cover in these conversations.
As for the dealer insisting on an open Center valve. He is either clueless, stubborn or miserable.

the ported filter is designed for applications where there is at least 175psi pressure on the return line . As in a hydraulic motor or return lines from a loader etc .
The oil is returned to a location past the transmission pump discharge but prior to the filter element .
The line to the front pump is usually supplied with what ever oil the transmission pump has left over . After the transmission bearings are lubricated, the high/low clutch and the PTO clutch/brake .
What oil the front pump does not take flows through the oil cooler into the reserve tank . When the reserve tank is full the extra oil is routed back to the transmission case .
During continuous high demand hydraulic loads the transmission pump can not keep up with the demands of the front pump. The gallon or two of oil in the oil cooler and front reserve tank is used to supply the front pump. Then the front pump cavitates.
Retuning hydraulic oil via a ported filter cover vs just dumping the return oil into the transmission case will supply the front pump with all the return oil plus what ever the transmission pump can send .
Otherwise the 23gpm front pump is only going to pump 5-6gpm continuous.

Looks like you knew the answers

 

[buickanddeere]

Everyone is overlooking the fact that a Shaver post driver creates a low volume intermittent demand. The lift cylinder is on the order of maybe two and a half inches in diameter. There is no high volume demand and no continuous demand.

Length of stroke and how long does it take to raise the hydraulic ram?

 

[RickB]

E

Length of stroke and how long does it take to raise the hydraulic ram?

From memory the stroke is in the 48” range and bore is no more than 2”.
Time to raise depends on GPM, as you know.

Edit. I see that I put the cylinder bore at about 2-1/2 inches in a previous response. It certainly isn’t more than that and the 2 inch figure may be closer to the truth.

 

[buickanddeere]

E

From memory the stroke is in the 48” range and bore is no more than 2”.
Time to raise depends on GPM, as you know.

Edit. I see that I put the cylinder bore at about 2-1/2 inches in a previous response. It certainly isn’t more than that and the 2 inch figure may be closer to the truth.

I was running some numbers to figure if the front pump is starting to cavitate in case the front tank and cooler run empty .

 

[RickB]

I was running some numbers to figure if the front pump is starting to cavitate in case the front tank and cooler run empty .

Many moons ago I ran a Shaver HD8 on a 3020 and ran the return into the rear axle housing via the plug to the left (?) of the top link bracket. Never had any cavitation issues. The on,y ported filter cover I ever had was a fabricated one we made for a 4010 when we put a 148 loader on it with an independent CC valve.

 

[Tx Jim]

My knowledge of Shaver post driver hyd's is very limited so I'm not commenting any more.

 

[buickanddeere]

Many moons ago I ran a Shaver HD8 on a 3020 and ran the return into the rear axle housing via the plug to the left (?) of the top link bracket. Never had any cavitation issues. The on,y ported filter cover I ever had was a fabricated one we made for a 4010 when we put a 148 loader on it with an independent CC valve.

. The Waterloo tractors were designed with a higher capacity transmission pump than the Mannheim/Dubuque tractors .

 

[RickB]

. The Waterloo tractors were designed with a higher capacity transmission pump than the Mannheim/Dubuque tractors .

No doubt. The whole idea of the transmission (charge) pump having a fraction of the capacity of the piston pump was a dumb idea looking back.

 

[buickanddeere]

No doubt. The whole idea of the transmission (charge) pump having a fraction of the capacity of the piston pump was a dumb idea looking back.

The engineers either had the ported filter cover in mind from the start of design . Or they figured the oil cooler and front tank would hold enough oil .
In the 1950’s there were not thinking of backhoes , large loaders with hydraulic buckets and hydraulic motors .
Keeping the transmission pump small would save some power and fuel .
I wish that some jobber shop would build high flow transmission pumps for the Dubuque/Mannheim tractors .