THE METAL BOX THAT DEFIES GRAVITY (LEARN ALL ABOUT THE ELEVATORS)

in #steemstem7 years ago (edited)

There is this young boy of fourteen years who happens to be my brother he is much younger, smart and intelligent he is on the verge of writing final exams in secondary school. And with what I see in him he is likely to take after me in the engineering profession.

Just last week we were discussing on how I went to a mall and the first time I used an escalator in the mall. He told me he had seen one but what he was yet to do was use one. He then asked me a question about elevators as he had never seen one.

how does lift work?

First, the question struck me on a bad side, I happened to work in a construction site where one was installed but I never had the chance to see all that was going on there as we were busy with works on my own.

I had to correct him about the name

Some countries like United kingdom, new zealand and Nigeria calls the elevator “a lift” I said to him. The elevators help you move against gravity faster to what level or floor you are going to. It is fun to use one, but I had not answered the question I had to tell him what I saw on site then about the pulleys and ropes that that elevator used. But I was not satisfied as I picked up my phone to dive into the world of research.

I am very sure many have used an elevator at one point or another, but did you know how it operates or what type you used?


The elevators


To that layman, the elevator is just a metal box you enter with few buttons that take you up

Yes, that man is right but there is more to elevators than a metal box the elevators are simply a type of vertical transportation that aids movement of people, tools, and goods within a vessel, building or structures where they are installed.

Elevators generally are powered by electric motors which drive the traction cable and counterweight or hydraulic pumps to cause a rise in the cylindrical piston like a jack. The elevators are used in agriculture and manufacturing as a conveyor to transport materials in continuous forms either to the bin or silos.

There are several types of elevators which we would be talking about later on. But we cant talk about the types of elevators without discussing how they came to be.

How elevators came to be


If I told you the earliest form of elevators which were known to be referenced came to be in as early as 236BC. A man known as Vitruvius who was a roman architect reported that Archimedes had probably built the first elevator in 236BC which was powered by hand or by animals. (that would be painful if you asked me).

In the 17th century, prototypes of elevators were found in the palace buildings of England and France. But in recent years elevators were based on ropes and hoists to drive the elevator the invention of the screw drive brought a huge step in elevator technology thanks to the Russian Ivan Kulibin.

This post would be incomplete without talking about the types of elevators we have

Types of elevators


To understand how the elevators work it is essential to know first that elevators are classified on basis of propulsion or simply the powering system. And there are five types of mechanisms which are used to power elevators which also forms the ground of their nomenclature.

  • The traction elevators
  • The hydraulic elevators
  • The electromagnetic propulsion elevators
  • The pneumatic elevators
  • The climbing elevators

Join me as I discuss each mechanism of the elevators and how they work

The traction elevators


The traction elevators are the most popular types of elevators you see around. The elevator cars or the metal box where you stand in are pulled up by ropes which are pulled over a deeply grooved pulley. The deeply grooved pulley is referred to as sheave in the industry. Sometimes the traction elevators are designed in such a way that two metal boxes (elevator cars) always move synchronously in opposite directions making them counterweights to each other.

Mechanism of operation


The traction elevators are of two types which are geared and gearless traction type elevators.

The gear traction elevators work using an electric motor which could either be an alternating or direct current type. These elevators make use of worm gears for mechanical control and they control movement by simply using a rope (steel rope) over a drive shaft which is connected to a gearbox which is in turn controlled by a high-speed electrical motor. The alternating current motors were used due to their cheap cost and economic feasibility and they did their jobs perfectly where low-speed applications were required.

As buildings grew taller, there was a need for fast elevators as the slow speed would not just do the job then the direct current motors came to play but they were powered by stand-alone devices which have the ability to operate both modes. They are used where there is no power spike in the building where the elevator operates.

The gearless traction elevators make use of direct current motors at low revolution per minute but at a high torque. This means the application of this type of elevators are where a large power is needed, these elevators are not connected to a gearbox but rather attached directly to the shaft. They are known for their speed advantage and have brakes attached for safe operation just in case of a power failure they would bring the elevator cars to a halt.

The hydraulic elevator


If you are familiar with the hydraulic power then you should know these are powerful types of elevators.

The hydraulic elevators are quite different from the traction elevators they are powered by a piston that travels inside a cylinder. The hydraulic powered elevators also have electric motors which pump hydraulic fluid into the cylinder to move the piston which in turn moves the elevator cars. But there are certain electrical valves which control the release of the fluid.
The hydraulic elevators are used in tall buildings of up to five or six stories high and could operate at speeds up to 200 ft per minute. The hydraulic elevators are of three types namely;

  • Holed or conventional hydraulic elevator
  • Hole-less hydraulic elevator
  • Roped hydraulic elevator

The holed or conventional hydraulic elevators

These types of hydraulic elevators have their cars mounted on a piston or ram that travels inside a cylinder. They extend into the ground with their depth equal to the height at which the elevator would rise. These type of system is also referred to as inground hydraulic elevator.

The hole-less hydraulic elevators

The hole-less hydraulic elevators are quite similar to the holed hydraulic elevator. It consists of pistons which are mounted inside the pathway which raise and lower the elevator car. This kind of elevator serves as a solution to buildings built on bedrock, high groundwater, and unstable soil conditions. The hole-less hydraulic system uses a direct acting piston to raise the elevator car.

The roped hydraulic elevator

The roped hydraulic elevator has the advantage of increasing the rise of the hole-less elevator to about 18 meters without the need for a below ground cylinder. They have their pistons attached to a sheave which has a rope passing through it. One end of the rope is attached to the elevator car while the other and the other is secured at the base of the pathway. The rope hydraulic system has a governor which regulates the elevator speed.

Working mechanism of the hydraulic elevators


Think of your hydraulic elevators like a hydraulic jack that you use on your cars when you have a flat tyre.

Just as the load on the jack is applied on top the load of the hydraulic elevators (which are the elevator cars) are on top. While applying force to these jacks (I mean during the lifting and dropping of the bar) you are carrying out the function of the electric motor in this case and the ram which is that which responds to the movement of your pump moves uplifting your car.
When your car gets to a height you stop. And do what you want to do which is to change the tyre of your vehicle and when you are done, you release this pressured oil and the jack just goes down. This same ideology is applied to the hydraulic elevator.

Hydraulic elevators have electric motors like I stated earlier these electric motor is responsible for pumping hydraulic fluid in the cylinder. When this fluid under high pressure Is pumped into the cylinder, the ram inside the cylinder is pushed forward which in turn lifts the elevator cars where the passenger is
This elevator cars move in a guide and at the required height the control system just like your car jack stops the fluid from going in and keeps it stationary allowing for the passenger to exchange goods or move out.

Conclusion


I would not be able to finish this today because I want you to read and digest this just as I have explained to my brother.
Today we have learned about the elevators, their history and how Archimedes may have built the first elevator, we also discussed two types of elevator out of the five types which are the traction elevator and the hydraulic elevator.

The traction which is commonly used has the geared and the gearless, we referred to their mechanism of operation and also the hydraulic elevators.

Stay tuned to my blog as I discuss the electromagnetic elevators, the pneumatic and climbing elevators.
Thank you for reading!

References


For further reading kindly get any of these books or visit the following links
1|2|3|4|5|6|7|A First Course in Hydraulics - John Fenton



If you write STEM (Science, Technology, Engineering, and Mathematics) related posts, consider joining #steemSTEM on steemit chat or discord here. If you are from Nigeria, you may want to include the #stemng tag in your post. You can visit this blog by @stemng for more details.

SteemSTEM


Sort:  

What goes up must come down, well elevators have the liberty of going up and staying there. I hope your little brother understood as I have now.

Yeah that is true... Everything comes down crumbling at some point..except for the crypto market 😅😅
I explained to him and even took him out to use one. Wait for the concluding part.
Thanks for stopping by.

Interesting post. Thanks for sharing!

Thank you.

Well explained article..

I thought evry elevator relies on pully mechanism..!! now i knw there are many others too..!!!! 😃

waiting for the next part..!

~ Christina Jane
Engagement_Officer.png

Thanks Christina.. I actually thought so till i started my research on it too.. I am glad you found this interesting.
Thanks for being here.

best wishes to u..! 🙌

Thank you.

We enjoy the best of both world; we get to use American and UK English. So in Nigeria, you can use boot or trunk, lift or escalator or elevator.

Nice to see the workings of the elevators. Since the buildings here are hardly more than ten storeys high, I prefer the stairs as a means of exercise :)

Hehehe.. I used to prefer the stairs till i worked in a tall building and for every little thing i forget (tool) my boss would ask me to go down and pick it up i did it for like four or five times a day and for 6 months. Although i had strong legs but my laps... Oh goodness!

I wished the elevators were made for public use in that building at that time. But these things are saviors and they help quite a lot.
Thanks for being here greenrun.

An interesting post.

Thank you saho for dropping by!.

An interesting post.

I've seen different types of elevators in movies.
If you live and work in a city, elevators undoubtedly play a crucial role in your everyday life. In fact, they move more than a billion people daily, making them the world’s most widely used and permit me to say it is the safest means of transportation.👍

Trust me they are not save especially if they malfunction or the power goes off while you are in them.. But they are quite easy and makes us want to go to that tall building without having to run out of breadth.

That's some of the demerits of elevators. We can't shy away from that.

Yes it is.. Thanks for stopping by.

Elevators are a necessity in organizations where there's a large height.

Back when I was on industrial training at Egbin power plc. I could remember a day we carried out a maintenance on the 8th floor. My superiors sent me to get some tools in the ground floor. I hurried to the lift but unfortunately it was taken by some set of people already. I had to travel through the staircase.

I was fortunate that the trip was towards the ground and not upwards, I would have had an unwanted thigh exercise. Even the down trip was hell.

Good post @adetola

Hehehe... Trust me the upward trip would give you a good thigh cramp for that week..
I am glad you found this interesting. Thanks for stopping by.

i remember my first time in an elevator, it felt like all my organs were going down while i was going up. I only tried to comport my self as i was "eyeing" a pretty lady in the elevator.

it is nice to learn how those things work. Nice post sir

Hehehe.. The same happened to me i had to close my eye. I am used to it now.
I hope you didn't mess up?

Thanks for stopping by.

As a sharp guy, i didn't.
If you want her number, i can give it to you

😑😑.. Later he will sey he is an introvert 🏋️🏋️

Informative... I am really fascinated by some of these mechanisms

Thank you. I am glad you found this informative.