An elevator uses a counterweight to balance the car’s weight. A motor and cables raise and lower the car. Safety features, like brakes and speed governors, prevent accidents.
Imagine a terrifying situation where you have a very important meeting in say a skyscraper – 30 floors that everyone in your city brags about them – and your meeting will be held in the 29th floor.
Okay here is the situation… You are Late!! The meeting will start in less than 10 minutes, however this is just the beginning, the bad news is… THE ELEVATORS ARE NOT WORKING!!!!!
So you’re stuck in just 2 options. Either to take the stairs, if you are a highly trained athlete it’ll take you at least 45 minutes to reach your destination. The other one is to call them pretending you have a very bad flu and you could not move from your bed despite the cost of such call.
So how does this little metal box called elevator can have a very crucial role in our lives.
How does an elevator work?
Elevators are mainly concerned with energy. When you’re trying to walk up or down stairs you are now walking against gravity which enforces you to expend Potential Energy. Climbing up the stairs will result in increasing your potential energy while climbing down the stairs decreases it; which is an example of the law of conservation of energy.
Thus, in Theory, and to simplify it without the physics complications, elevators are devices that makes the potential energy in a person increase or decrease without even costing them to produce this kind of energy – that’s simply about How does an elevator work?
lift mechanism
The terms “elevator mechanism” and “lift mechanism” can be used interchangeably to refer to the system that raises and lowers the elevator in a vertical shaft.
There are two main types of elevator mechanisms: traction and hydraulic.
lift mechanism – Traction elevator mechanism
Traction elevators are the most common type. They use a system of steel cables, sheaves (grooved pulleys), and a counterweight to raise and lower the car. The cables are attached to the car on one end and to the counterweight on the other. The sheave is connected to an electric motor. When the motor turns, it winds the cables around the sheave, which raises the car and lowers the counterweight. The counterweight helps to balance the weight of the car and reduce the amount of energy needed to operate the elevator.
lift mechanism – Hydraulic elevator mechanism
Hydraulic elevators use a piston and cylinder to raise and lower the car. The piston is filled with hydraulic fluid, and the cylinder is connected to the bottom of the elevator shaft. When the pump pushes hydraulic fluid into the cylinder, the piston extends, raising the car. When the pump releases the hydraulic fluid, the piston retracts, lowering the car.
Both traction and hydraulic elevators have a number of safety features, including:
- Speed governors: These devices prevent the elevator from going too fast. If the elevator starts to move too quickly, the governor will activate the brakes.
- Emergency brakes: These brakes are activated if the cables break or if there is another problem with the elevator.
- Door sensors: These sensors prevent the elevator from moving if the doors are not closed.
In addition to the basic elevator mechanism, elevators also have a number of other components, such as:
- Control system: This system controls the movement of the elevator and all of its safety features.
- Door operators: These devices open and close the elevator doors.
- Call buttons: These buttons allow passengers to call the elevator to their floor.
- Indicator lights: These lights show which floor the elevator is on and which direction it is moving.
Elevators are complex machines, but they are essential for transporting people and goods in tall buildings. The mechanisms that make them work are a marvel of engineering.
Elevator’s major components
This image will help us describe the following mechanism. The elevator consists of a lot of intertwined and crossed parts, however the most popular/ important parts are:
- The Counterweight
- The Car (metal box)
- Pulley system with electric motor
- The Cables
The pulley system is pulling up or down the car by metal cables which enables the elevator to move through different floors, very simple right… Not exactly!!!
The Counterweight
Anyway how does this metal weight/hoist called Counterweight contribute to this mechanism? It simply contributes Balance.
The Counterweight is balancing the elevator’s movement, weighs about half a fully-loaded car. When the counterweight goes up the elevator moves down and vice versa as simple as that, however, it has a great benefit.
Let’s imagine the corresponding situation to have a better picture. Without a counterweight, the whole load will be mainly on the pulley system and the cables. That requires the motor to generate more energy to lift the car. In spite of just requiring to say 500 KJ with the existence of the counterweight, now it needs to double the energy to lift the same load.
The counterweight has also its own role with the safety system in case of cables and braking system, the strain on the cables will decrease making the elevators a little bit safer.
While the braking system will have the same case with the counterweight, the elevators now can use less amount of braking to slow down the elevator’s speed.
Imagine if there were no counterweight: a heavily loaded elevator car would be really hard to pull upwards. But on the return journey, the elevator would tend to race to the ground all by itself if there wasn’t some sort of sturdy brake to stop it.
Speed Governor
In order to control the speed of the elevator, there has to be a separate speed-regulator machine which is called the Speed Governor. It is avery complicated flywheel supported with massive mechanical arms.
The speed governor has the full control over the elevator’s speed. So if there is a problem with the elevator that makes it move too fast, the first mechanism inside the speed governor trips one or more of the braking system.
Moreover, it can cut off the power from the lift motor. If this fails in making the elevators slow down; the other mechanism will allow the arms inside the governor to fly up even further to stop the elevator from moving.
Safety System
Another terrifying image. What if all the 4 cables holding the elevator snapped?! Well, before 1860s you would have been flying in the elevator like Einstein in his thoughts. However, after this date a simple mechanism invented by Elisha Graves Otis to have ratchet system as a backup.
Each car ran between two vertical guide rails with sturdy metal teeth embedded all the way up to them. At the top of each car, there was a spring-loaded mechanism with hooks attached. If the cable broke the hooks sprung outward and jammed into the metal teeth in the guide rails, locking the car safely in its position.
So you are stuck between floors but at least you are not smashed, so just wait for help.
Not only is this but also there another emergency system for the elevator. A giant hydraulic or gas spring buffer located at the bottom to cushion in case if there were any problems with the braking system to absorb the impact of collision.
How elevators work
Elevators come in two main types, each with a different working principle:
How elevators work – Traction elevators:
- Most common in high-rise buildings.
- Imagine a pulley system with a motor, sheave (pulley), steel ropes, elevator car, and counterweight.
- The motor turns the sheave, which winds the ropes and raises the elevator car.
- Key component: The counterweight balances the car’s weight, making it easier for the motor to move it.
- Think of it like a seesaw: As the car goes up, the counterweight goes down, and vice versa.
- Modern systems use sensors and control panels for smooth operation, accurate floor stops, and safety features.
How elevators work – Hydraulic elevators:
- More common in low-rise buildings.
- Picture a large piston and cylinder filled with fluid.
- An electric pump pushes fluid into the cylinder, extending the piston, raising the car.
- To descend, the fluid is released.
- Pros: Simple design, easy maintenance.
- Cons: Limited travel height due to the size of the cylinder and pressure limitations.
elevator how it works – step by step
Lifts, also known as elevators, are those nifty contraptions that whisk us up and down buildings with ease. But have you ever wondered how these marvels of engineering actually work? Let’s dive into the fascinating world of lift mechanics, step-by-step!
How lift works – Step 1: Calling the Lift
It all starts with a simple press of a button. Whether it’s on the ground floor or your desired destination, this sends a signal to the lift’s control system. This “brain” of the operation tracks the location of all lifts and assigns the closest one to your request.
How lift works – Step 2: Powering Up
Once assigned, the chosen lift receives an electrical signal from the control system. This activates the motor, which is usually located at the top of the shaft.
How lift works – Step 3: The Cable Dance
The motor’s energy is channeled into a system of steel cables wrapped around grooved wheels called sheaves. These sheaves act like pulleys, guiding the cables that connect the lift car and a counterweight.
How lift works – Step 4: Up, Up, and Away (or Down, Down, and Away)
When you press the “up” button, the motor rotates the sheave in one direction, pulling the cables and lifting the car. Conversely, pressing “down” reverses the motor’s rotation, unwinding the cables and lowering the car.
How lift works -Step 5: The Counterweight’s Balancing Act
Remember that counterweight we mentioned? It plays a crucial role in balancing the lift’s weight and reducing the energy needed for movement. As the car goes up, the counterweight goes down, and vice versa. This creates a sort of seesaw effect, making the lift’s movements smoother and more efficient.
How lift works – Step 6: A Gentle Stop
As the lift approaches your desired floor, the control system signals the motor to slow down. Brakes are then engaged to bring the car to a smooth stop, perfectly level with the floor.
How lift works – Step 7: Doors Open, Welcome Aboard!
Finally, the doors slide open, inviting you to step into the lift and continue your journey. Once all passengers have entered or exited, the doors close again, and the cycle repeats for the next call.
Till this point we reach the end of elevators’ story of How does an elevator work? Contact TTI Lift now for a free consultation and elevate your life!