[tommy78]

Hi filks, I have that pomp Hydraulic Hand Pump (700 Bar - 2700 cm3) - EZ-Tools Professional Tools

and when I work it I need to pomp as far as 400bars, I am looking to help myself and make an engine, like removing the hand and installing some fixture that will work itself using electrictity

Any idea what to use and how to make it ?

[handlewanker]

Hi......for a start the pump pressure to the cylinder relies on the force of your arm muscles and the length of the lever handle.......if the pump can go as high as 400 bar then the rest is just construction......I imagine you want to construct a power press for about 3 tons.

A lot depends on the distance the lever moves to pump one stroke.

If it moves in an arc of about 200mm length then you could make a frame to hold the pump body with a wheel and a crank pin set at 100mm from the centre to get a stroke of 100mm for the 200mm handle travel.

The wheel would be driven by an electric motor having a suitable vee pulley reduction to give you the pump rate.

To make a power driven pump working at that pressure you would need to have engineering skills and hydraulic knowledge.
Ian.

[tommy78]

if the pump can go as high as 400 bar then the rest is just construction......I imagine you want to construct a power press for about 3 tons.
.

my pomp is able to make it 700bars, and the press with cylinder as much as 100 tons. to make it 400bars with my muscles I need to work pretty hard.

[handlewanker]

Hi, it's possible to motorise your hand pump.....make the frame to hold the pump body down low in the horizontal plane with the handle on top.

This will enable you to attach a linkage down from the crank pin to the handle.

Calculate how much oil the pump body holds to allow for the full stroke of the press cylinder.

You might have to attach a larger tank to the pump body or remove the pump section and attach it to another tank.

I think you will need a 3 phase motor if you have 3 phase......or a 3 hp single phase but that will make your light go dim when you switch it on.

If you don't have 3 phase you could make a rotary phase converter to get 3 phase from your single phase mains supply.

If the motor runs at 1,420 rpm you will have to have some pulleys with vee belts to get a 1:12 speed .reduction............about 120 strokes per minute to the handle seems OK.
Ian.

[tommy78]

Gosh...why would I need to change the oil tank ??? what is oil tank ? The pomp is one piece I dont thin I can add any "oil tank" to that...

Also why would I need 3 phase? would it be that complicated for the small engine to reach approx 50 kg power so it would be able to move the handle ?

[handlewanker]

Hi.....the device you posted consists of the pump at one end of a round oil container........the cylinder on your press might need more oil than the pump container holds when it's fully extended..........do a test.

The motor is probably the easiest part to do and you'll have to experiment to see how much power you need to work the handle at the stroke rate you need.

If you have mechanical knowledge this will be simple to understand and design.
Ian.

[tommy78]

Cylinder and pomp I bought in one shop, they say it woks fine together, cylinder is quite large it can go as much as 100 tons.Pomp is 700 bars.
Power that I to push the lever with my muscles is what I presume approx 50 kg ( on the pomp it shows 400bars)

So there I have two oprtions - use a motor to move the lever or disconnect the lever and use the motor to move the small cylinder in the pomp ( the cylinder that is now moved by the lever )

[handlewanker]

Hi.......that lever applies a large part of the pump pressure by way of the leverage exerted to the pump plunger.

If you are applying 50Kg to the end of the lever this would probably be a ratio of 20:1 on the pump plunger......that means you need to apply a huge down force directly to the pump plunger.....not very easy to achieve.

In my opinion it would be simpler to make a connecting rod type link to push the handle up and down......I don't know how you could connect the motor to just the pump plunger, but no doubt with a clever bit of designing it can be done, but the force on the plunger would be very large without the handle to apply most of it.

I think maybe a direct connecting rod to the pump plunger attached to a flywheel with a crank throw of about 10mm "could" work with pulleys and vee belts to get the speed reduction........that might work out in the region of 1:100 reduction or more or you could use a bigger motor to pump at the same rate........but I think it will be more complicated to achieve, whereas the handle connection is simple.( uses a smaller motor) as it's already made to work in that way.
Ian.

[inov8r]

Hi.......that lever applies a large part of the pump pressure by way of the leverage exerted to the pump plunger.

If you are applying 50Kg to the end of the lever this would probably be a ratio of 20:1 on the pump plunger......that means you need to apply a huge down force directly to the pump plunger.....not very easy to achieve.

In my opinion it would be simpler to make a connecting rod type link to push the handle up and down......I don't know how you could connect the motor to just the pump plunger, but no doubt with a clever bit of designing it can be done, but the force on the plunger would be very large without the handle to apply most of it.

I think maybe a direct connecting rod to the pump plunger attached to a flywheel with a crank throw of about 10mm "could" work with pulleys and vee belts to get the speed reduction........that might work out in the region of 1:100 reduction or more or you could use a bigger motor to pump at the same rate........but I think it will be more complicated to achieve, whereas the handle connection is simple.( uses a smaller motor) as it's already made to work in that way.
Ian.

Not true. The shorter the lever gets the less the crank shaft has to throw. Shorter throw = more leverage.