Home > Article > A to Z Of Hydraulics Engineering -The Basic Principle Of Hydraulics

A to Z Of Hydraulics Engineering -The Basic Principle Of Hydraulics

The principle of hydraulics is based on Pascal's famous theory. It states the pressure of the liquid produced in an enclosed structure has the capacity of releasing a force up to ten times the pressure that was produced earlier.

Through hydraulics, the basic result to be achieved is that with little pressure, a great force should be produced.

The Evolution Has Begun

With the invention of hydraulics lift kits, you can actually make your car dance. These cars are popularly called as the "lowriders".

They are named for a specific reason. These cars are custom- made to ride very low to the ground. The hydraulic systems installed in these cars make them hop around by raising and lowering these cars. To make these cars look like they're hopping, the hydraulic systems also demand the installation of 12 to 48 volts Hydraulic Pumps. These hydraulic inventions can be seen in movies like The Fast and the Furious and in some lowriding competitions.

How The Basic System Works

The working of a hydraulic system is very simple. The basic fluid used in this system is oil. A hydraulic machine has two or more cylinders that are connected to a single pipe containing the oil and the pistons that helps in pushing the fluids in the cylinders. Even the car brakes are based on the hydraulic system.

When you apply your car brakes, your brake pedal makes the piston to act and apply force on the master Cylinder.  The main pipe is connected to four slave pistons that activate the brake pads of your car to the brake rotor, which in turn makes the car come to a stop. The basic hydraulic components are as follows:

•  Hydraulic Cylinders: These components of the hydraulic system are those in which, pressure is applied on the fluids (oil), to get the desired force. The force acquired is used to power the hydraulic machine of car brakes, cranes, turbines and a large number of excavators. These cylinders also include the pistons of different sizes. The hydraulic pistons are used to push down the fluids in the other cylinder, which in turn exerts the pressure and pushes it back again.

•  Hydraulic Pumps: The hydraulic pump is a component that is responsible for supplying the fluids to the other essential parts of the hydraulic system. The power generated by a hydraulic pump is about ten times more than the capacity of an electrical motor. There are different types of hydraulic pumps such as the vane pumps, gear pumps, piston pumps, etc. Among them, the piston pumps are relatively more costly. But they have a guaranteed long life and are even able to pump thick, difficult fluids.

•  Hydraulic Wrench: A hydraulic wrench is used to tighten the nuts and bolts.

•  Hydraulic Lifts: Hydraulic lifts are the similar components used for powering the hydraulic system in cars such as the lowriders. These lift kits are available in any custom- made car shops.

•  Hydraulic Press: This is a process in which, the pressure is compressed to a full extent. The structure again
involves two cylinders of different diameters and two different sizes of pistons. In order to generate a powerful pressure, the basics of Pascal's Law are followed. The pressure is created by applying force and pushing the smaller piston through the cylinder and the fluids are pushed through the connecting pipe to the larger cylinder till a great pressure is exerted. The use of a hydraulic press is seen in the process of crushing cars. For crushing cars, a motor powers the hydraulic press. A car crushing hydraulic system has the capacity to generate about 2500 pounds per square inch (psi) and apply a force of about 200 tons that is more than enough to crush any car. A hydraulic press has the potential to crush an aluminum metal into a thin scrap of paper. The hydraulic press too is comprised of many components such as the pumps, the various valves, the pipes and the engine.

•  Hydraulic Motors: This is the one most widely used. The power in hydraulic motors is achieved with the help of exerting pressure on the hydraulic fluids, which is normally oil. The benefit of using hydraulic motors is that when the power source is mechanical, the motor develops a tendency to rotate in the opposite direction, thus acting like a hydraulic pump. 

Pascal's Law strictly states "pressure exerted on a fluid is distributed equally throughout the fluid".

Where Are Hydraulics Used

Hydraulics is used in many machines that we see in our daily lives. Some of its uses are:

•  Hydraulics is used in heavy equipments like log splitters. You can find the simplest hydraulics system in
log splitters as it consists of most of the components of a basic hydraulics system such as the hydraulic pump, an engine, the hydraulic cylinders, the various valves and the hydraulic pistons.

•  The heavy- duty machines make use of the hydraulics system that is often seen at construction sites and other excavations. A large machine such as the excavator may weigh anything around thirty tons but it has the capacity to move around easily and carry mud weighing about two tones without any difficulty. An excavator has a motor for each of its tracks and a motor for swinging its huge arm that all runs on the system of hydraulics. Other construction vehicles making use of hydraulics system include the loading machines, also known as the skid. This machine makes use of 3 pairs of hydraulics pistons and also hydraulics motors on each of its four wheels. Another vehicle that we often see in our daily routine are the garbage dump trucks. They make use of all the hydraulic components. The only exception in its case is the use of telescopic cylinders that helps them to attain the feat of positioning the dump bucket to an almost vertical stance to allow the garbage fall over.

•  Hydraulics is also used in mechanical wheel chairs to push the wheel chair forward. It is also used for aircraft landing gears to push the wheels out when landing the plane.  Precautions For Handling Hydraulics System  The components of a hydraulics system should be handled very carefully. It is not advisable to touch the hydraulic machine even if the system may not be running since the fluids may still be flowing under pressure. Even if the hydraulic fluid is found leaking, no one should attempt to touch it because the fluid pressure can tear through your skin.


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