Compressed air of 6 to 7 bar can be used to drive a small air motor to generate hydraulic pressure up to 700 bar.Generating a high hydraulic pressure up to 700 bar by compressed air of 6 to 7 bar and a small air motor. That is the principle of a hydraulic air pump unit. It is an extremely compact, portable power source with the most important advantage being that it can be used any place where compressed air is also available.
The latest Turbo II Air Hydraulic Pump series from Enerpac also offers a wide range of application possibilities in this respect.
Compressed air can be used for more than just pneumatic tools, for pneumatic operation of certain switch operations or simply for cleaning an object.
Compressed air can also be used as the energy source for an air motor, which in turn drives a hydraulic pump.
Due to frequently high weight, in most applications these types of installations are for generating power that is only used in a stationary position.
Mobile source of power - but how often doesn't it happen that somewhere in a company or outdoors some power must be utilised quickly for a short period of time.
For example during maintenance operations, to pull a bushing from an axle, lift something or clamp something down.
High-pressure hydraulics is the most suitable power source for this, for tonnes of power can be brought to bear by this in a very simple way.
Hydraulic tools, however, also have the property that a pump with a drive is also necessary.
A combination you don't carry around everywhere you go.
So in such cases the well-known manual pump as mobile hydraulic power source is a practical resource.
Easy to take anywhere and with sufficient power to carry out the particular operations.
The disadvantage of a hand pump - the name already explains it - is, however, that you need manual power for this and that often many long strokes must be made to build up sufficient pressure.
From a technical occupational health and safety standpoint, this is not exactly the most ideal manner of operation.
The hydraulic air pump offers a better solution in this regard.
After all, compressed air is available at most locations in companies.
The way it works - at first sight the hydraulic air pump is nothing but a small closed container with a foot pedal and connections for compressed air and oil.
But the secret is under the lid, for the container also serves as oil reservoir with a small linear (plunger) air motor with integrated high-pressure hydraulic pump.
By using new technology, the power/weight ratio has been maintained at a favourable level, the entire pump unit thus having a weight that can be carried.
Operation is very easy.
The unit is simply connected to the compressed air system and connected to the Enerpac high-pressure hydraulic tools requlred.
This could be a cylinder, but it could also be a clamp, a nut splitter or a hydraulic bushing puller.
Next, the air motor is put into operation with the foot pedal (or manually) via an air valve and the oil flow ensures that sufficient hydraulic pressure is built up in order to exert the required power.
The hydraulic operating pressure can be adjusted, depending on the model, from 8.5 to 35 Mpa (85 to 350 bar) or from 10 to 70 Mpa (100 to 700 bar).
This is done by means of the air pressure or by the pressure regulator valve built in behind the oil gauge glass.
By releasing the pedal, it will automatically return to the centre position and the hydraulic pressure will be maintained by means of a non-return valve.
This keeps the system under pressure.
Pushing the pedal in reverse direction is sufficient to allow the oil to flow back and restore the single-stroke cylinder to the original position.
The pressure is now released.
For longer hose lengths or for applications where controlled back flow and thus dual-stroke are necessary, a model with a built-in four-way valve is available.
In this case, the four-way valve ensures that the oil flow is reversed to allow the cylinder to return to the original position in a controlled manner.
Advantages - the hydraulic air pump provides important advantages.
It is compact and weighs, depending on the tank volume, no more than 7 kg.
Due to the very low noise level, user fatigue is prevented.
In other words: it is portable, making it possible to generate high power in a simple manner at any random location where compressed air is available.
That is an important advantage for work that must be carried out on site, such as maintenance and installation operations.
Furthermore, many operations involve concentrated application of power and movement to a lesser degree.
Therefore, only a minor oil flow is necessary and a pump drive with little capacity (compressed air) already suffices to generate a pressure of 700 bars and a corresponding power of about 25 tonnes Another important advantage is the high pressure delivered by a hydraulic air pump.
For enormous power can be generated with 70 Mpa (700 bar).
Power for which, normally speaking, sizeable and heavy tools are necessary.
High-pressure tools, on the contrary, are much more compact and thus also lighter.
From a technical occupational health and safety occupational standpoint this is also an interesting positive point.
In addition, working with hydraulics is often much faster and more efficient.
Applications - a hydraulic pump is an especially handy auxiliary tool if (extra) power is needed which is not feasible with hand tools or compressed air tools.
The Turbo principle already allows the pump to operate at an air pressure of approx.
1.5 bars and this creates plenty of application possibilities for maintenance, installations, in production or for quality inspections in this regard: * Brief lifting of heavy objects; * Pressing (e.g axle bearings and bushings); * Pulling bearings; * Splitting nuts; * Clamping down pieces of work to work on them; * Stamping or punching holes in plating; * Cutting cables; * Spreading (pulling apart) of flanges in pipes; * Alignment of steel structures or car bodies; * Assistance with assembly operations.
Limitations - of course, there are also limits to what is possible with the hydraulic air pump.
The fact is that the unit only holds a limited amount of oil (2.5 or 5 litres).
Furthermore, the oil yield and the oil pressure depend on the air pressure available.
Full capacity can only be utilised with a compressed air supply of approx.
0.7 Mpa (7 bar).
The advantage of a larger tank volume (5-litre reservoir) is that more oil is available and that longer or more cylinders can be used.
This may sometimes be necessary during lifting operations, when clamping down pieces of work or for alignment benches.
However, oil yield, pressure and power remain the same.