I remember when I was a little boy, of course, I was smart, energetic, inquisitive, and loved football. There was this plain land we always had evening fun and by fun, I mean football. People like 
There was this day I remembered the owner of the land wanted to develop his construction site we all could notice that but if it didn’t stop our play we were fine. I was in goal on this fateful day when I saw this big truck maneuver its way into our stadium.
I shouted trailer!
Don’t laugh that was what we knew their names to be at that time everyone looked up and ran for safety. I took a careful look at this heavy vehicle it has a whole lot of sand at the back. It was heavy indeed but as this vehicle parked I was looking at how on earth they could get the sand down fast enough. Which would determine if there was still going to be football after.
But to my amazement, after the other guy gave the go signal I saw this dump truck rise like the vehicle in transformers. I had to stand up from where I was sitting I was struck with amazement as I had never seen anything like that.
It practically lifted the sand like to was noting till everything slid down. I didn’t believe what I just saw till I came across some other ones that did the same as a little kid then I thought it was due to the size of the truck.
As I grew older I got to understand one term which I never forgot about and was behind why those dump trucks would lift tonnes of stone and sand and feel like it was nothing. The term is what I would be talking about today is the hydraulics system.
Hydraulics
Hydraulics has its origin from a Greek word and it is concerned with the applied science, technology, engineering and chemistry which involves the mechanical properties of liquids. If you read my post on elevators, I stated that the hydraulics are similar to the pneumatic system due to the mechanical properties of fluid they use.
The hydraulics make use of a basically in-compressible liquid for their operation and are very powerful inventions that have improved giant machines and their mechanism of operation. The study of fluid mechanics has helped in power control, transmission and generation by the use of pressurized fluids.
Right from its discovery in ancient times, the applications of the hydraulics are now being used in so many mechanical systems which have improved their operation. We now have hydraulic pumps, hydraulic elevators, hydraulic brakes and so much more.
Let’s talk about who invented or found out about this.
The hydraulic story
It all started in 1648 when a young French physicist made a discovery which is widely known today as the pascals law. Yes, his name is Blasé Pascal and he proposed the theorem which states that pressure which is exerted anywhere in a confined is transmitted equally in all directions throughout the fluid in such a way that the initial pressure differences remain the same.
This theorem laid the foundation for deep research into how compressed fluids could be used for energy. One genius who picked off from where he stopped in 1738 was Daniel Bernoulli another great man who then brought to light what is known today as the Bernoulli principle. The Bernoulli principle monitored or was based on the behavior of fluids under different conditions of height and flow. His work was later used in the network of high pressured pipes between power stations over long distances as they were used in steam power electricity generation.
It was at the end of the 17th century (1795) and towards the beginning of a new century when Joseph Bramah made a patent of the work he created “ the hydraulic press”. The hydraulic press was created based on pascals law, this started the revolution of hydraulics in the engineering field.
How do hydraulic systems work?
Let us take this little task if you can.
Get a syringe if you have one around that’s awesome, now remove the needle and draw water inside it when it reaches a certain level, take the measurement and place against your palm and block tightly the end of the syringe. Now, apply force to the plunger.
What do you notice?
The result you would have is that the syringe would refuse to press, would you believe if I told you not even a building can press that plunger down as long as its end is blocked. and the water would remain the same in volume as the one you filled in initially.
You may ask why but I have only one answer. Liquids are in-compressible this is one of their properties and this is one of the powerful tool used by hydraulics. The proof is the little experiment we carried out.
Now, how the hydraulic system basically works is by a magnification of power and let me explain that using the same experiment we practiced.
If that same syringe was turned otherwise and tightly fixed with a cock screw and a force is applied (i.e. through the needle hub) the other way. Here is what happens the fluid in the syringe would force out the plunger (making it extend) till it eventually falls off. But you would have applied little effort for that to happen.
The explanation above is a simple understanding of how the hydraulics work. But from a professional view, we do not use a syringe for hydraulics but there is something called a ram in the hydraulic systems. The ram in the hydraulic system is like the plunger in the syringe but much stronger and does lots of work. They are like the muscles behind the powerful machines you see around.
There is a pump inside every hydraulic system which pumps hydraulic fluid through a thin pipe. The pressure applied pushes the thick ram (just like the syringe and the needle hub) out of its protective housing called the cylinder.
This pipe is connected in such a way that the fluid that applies force on the ram is the same fluid that lets the ram back into its housing. Now as the ram is being forced out to carry out a specific task. Also, when this task is achieved this same pump pumps the hydraulic fluid in a counter flow direction to return the ram back to the cylinder.
well, this hydraulic fluid is not basically water although water could be used as a hydraulic fluid and it is a bad for corrosion, therefore, it is avoided. fluids like mineral oils with several additives, brake oils, and power steering fluids are used instead of water as hydraulic fluids.
This is basically how the hydraulic system operates and Pascal started this all by the law of Pascal he put in place so many years ago!
Engineering applications and achievement of the hydraulic system
If you don’t know the importance of what blasé pascal has done for us I have come here to share with you what importance and applications the hydraulics have done in our engineering world today. The power in fluid has spread through several machines and systems popularly known today. Such is the dump truck I talked about earlier, another is the crane that digs effortlessly and very fast.
One popular application is the hydraulic brake, I am sure you are wondering how powerful fluids are right now to lift your car when you can’t. The hydraulic press is another application, several applications in the conveyors, foundries, car wash, packaging system, power plants and many more.
I talked about the hydraulic elevators last week this is another great application of these systems. They have better life and made life easier.
Conclusion
The word hydraulics has its origin traced back to the greeks and it basically deals with the practical science, engineering, and chemistry of material application of liquids. The hydraulics are used in power systems to lift heavy equipment’s or to transmit power efficiency.
The hydraulic system was built on the knowledge of blasé pascal in the law and thereafter was history in the engineering field. Elevators, jacks machines, automobiles, dump trucks now operate using hydraulics.
I would have loved to talk about the sister of these systems which are the pneumatic systems but I would let that be for now. Watch out what air can do in my next article. Thank you for reading!
References
For further reading please get any of these books or follow the link.
1|2|3|4|5|6|7| Engineering Applications of Pneumatics and Hydraulics by EurIng Ian C. Thrner
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