Hydraulics on a lifting platform

What you need:

• Basic terms "physics"

Hydraulics - what is it?

• Hydraulics is the transfer of forces through a fluid system.
• The borrowing of the term "hydraulics" from the Greek, in which "hydor" simply means "water", is first of all Confusing, because in today's hydraulic systems - due to the higher boiling point - almost exclusively oil mixtures are used used.
• Systems such as the lifting platform, which uses oil to transform small forces into large ones in order to lift cars or other loads, therefore belong in the field of hydraulics.
• By the way: In theory, you could also work hydraulically with air. However, air and other gases can be compressed easily, in contrast to liquids, which are almost completely incompressible. Thus, using air would require a lot of useless work to compress the transfer material.

Lift - this is how it works physically

• In principle, the physical principles of a lifting platform are relatively simple if the term "pressure" - physically defined as "force per area" - is used in the explanation.


Pressure calculation in hydraulics - the formula simply explained

In a system based on hydraulics, forces are converted. For the …

• As already indicated, liquids can hardly be compressed, but the individual particles can be moved freely in the liquid.
• So if you have a closed volume of liquid and you exert pressure somewhere, it spreads very quickly in all directions. In simple terms, one could say: Even if the system is set up in such a complicated way, this pressure works in all nooks and crannies; in formulas: p₁ = p₂ with p as pressure.
• However, since pressure is physically defined as force per area, forces can also be transmitted with the hydraulic system. If the surfaces used change, the forces also change (inversely proportional); again in formulas: F₁/ A₁ = F₂/ A₂, where F each represents the forces and A each represents the areas. This formula is also used to calculate the power transmission in hydraulic applications.
• A small force applied on a small area can therefore develop a great force effect on a large area.
• In its simplest form, a (hydraulic) jack makes use of this. There you exert a small force on a small area and lift (with great force) a large load, namely your car. However, lifting the load involves a long commute.
• And the lifting platform that you will find in every car repair shop works no differently. Instead of being driven by hand (as is usual with the jack), this is of course done with a motor. However, the principle remains the same: a heavy load is lifted with little force.