Let Hydraulics Stop Your Car!
Hydraulics is a branch of engineering science which is concerned
with the mechanical properties of liquids and the general power
of fluids.
It is also focused mainly on the engineering uses of fluid
properties. Hydraulics, therefore, derived its theoretical
foundation fluid mechanics. Hydraulics spans a vast scope of
topics, ranging from science to engineering disciplines.
Among the concepts it covers include dam designs, turbines,
pumps, circuitry, pipe flow, hydropower, river channel behavior
and erosion.
Machineries using the principles of hydraulics include
bulldozers, backhoes, forklifts, cranes, and shovel loaders.
Hydraulics is also the reason why we see cars being lifted in
service centers so that technicians can work beneath them.
It is also because of this same technique that elevators
operate. Airplane surfaces are operated and controlled by
hydraulics, and even the brakes in our cars use hydraulics.
The idea behind hydraulic systems is simple. It states that
force applied at a point gets transmitted to the next point with
the use of an incompressible fluid, which is usually a type of
oil. In the process, the force is being multiplied.
In a simple hydraulic system, two pistons are connected by a
pipe which is filled by oil. These pistons are installed into
two glass cylinders which are filled with oil. The glass
cylinders are then connected to each other by a pipe filled with
oil.
When force is applied to one piston, the force is transferred to
the next piston through the oil in the pipe. Because oil cannot
be compressed, the efficiency is very good because all of the
force applied shows in the second piston.
The pipe which connects the cylinders can also come in any
length, shape and size, so it can bend, twist, or turn through
all the things separating the two pistons. This pipe can also be
a fork, which simply means that one master cylinder can drive
one or more slave cylinders.
In hydraulics, it is very important that the system eliminates
air bubbles. The presence of air bubbles in the system affects
its efficiency as the force being applied to a piston compresses
the air in the bubble rather than transferring it to the second
piston.
The brakes in a car are the simplest example of piston-driven
hydraulic system. As the brake pedal is pressed down, it pushes
the piston in the brake's master cylinder. This action drives
four slave pistons to push the brake pads towards the brake
rotor so the car stops.
The force coming from your leg is not enough to stop the car, so
car multiples the force. This is called hydraulic
multiplication. In most cars today, there are two master
cylinders driving two lave cylinders each.
This design allows the car to brake or stop even if there is
problem in the first brake, or if there is an oil leak. In other
hydraulic systems, valves connect cylinders and pistons to a
pump which supplies high-pressure oil. The valve applies forward
and backward force to the pistons.
You can see large hydraulic machines in construction sites.
These machines, driven by hydraulic power include excavators,
skidloaders (also known as the "bobcat", because it was the name
given by its first manufacturers), and dump trucks.
When you see these machines, remember that despite their
enormous sizes, the common force driving them comes from
hydraulics.