Lifts are a huge feat of engineering; they are capable of lifting dozens of people to higher levels in large buildings, and they can also provide an alternative way for people that have trouble walking to access the higher and lower floors of their house.
But how do lifts work? At Axess2, we know how everything works, from large scale lifts, like the one in Durham Cathedral, to traditional home lifts, so let’s delve into the physical world of lifts – literally, the physics behind them!
The Concept of a Lift
A lift uses a lot of physical mechanisms to lift a car up and to also lower it down. The secret behind this mechanism is that, to the outside world, it is covered up. However, the key parts of a lift include the following:
- One or more lift car
- Counterweights that help to balance the cars
- An electric motor that raises the car up and down
- Metal cables that hold the cars and the motors together
- Security systems
For some of these components, we will consider them in more detail and we will also take a look at the science behind each one.
How Lifts use Energy
When looking at the physics of lifts, the most important thing to know is that lifts use energy. For someone to go from the ground floor to the 13th floor, they must move upwards which goes against the force of gravity, which acts downwards. When you move upwards against gravity, you gain more energy in the form of gravitational potential energy.
The rule is that when you go up in a lift, you gain potential energy and when you go down, you lose potential energy; this is an example of a physical law known as the law of conservation of energy. If a lift consisted of a car, a few cables, and a pulley, it would require a lot of energy to lift the passengers, but when the lift car comes down, the energy cannot be returned, as it will be lost through friction in the cables and brakes.
However, even though the amount of energy that is used every day is huge, a lot of it can be saved by a device known as a counterweight.
Spotlight on: Counterweights
Lifts work in a different way to a hoisting system. Instead of a pulley and a motor that lifts the car, a heavy counterweight balances the car. This counterweight weighs roughly the same amount as when it is half-loaded. For example, if a car weighs 1200kg and it can hold up to 1000kg, the counterweight would weight 1700kg.
The idea behind the counterweight is that when the lift goes up, the counterweight goes down and vice versa. This helps by making it a lot easier for the motor to life and lower the car. For example, if the counterweight is 1700kg and the lift is 2000kg, the motor would only require lifting the extra 300kg rather than the full 2000kg; an energy reduction of 85% in this situation.
The counterweight also helps in providing less strain on the cables themselves, making the lift a lot safer, and it also reduces the amount of braking that the lift requires, adding greater control to the lift.
And there you have it. Now you know that the counterweight is of massive importance to all lift systems, which is why we pay so much attention, time, and effort into providing lift systems for all our customers.
At Axess2, we provide extremely high quality lifts to an array of domestic settings and businesses, in which we ensure that the safety of our clients is a top priority in all our projects.
If you want to know more about the various lifts that we can provide for you, then please don’t hesitate to contact us. Just give us a call today on 01200 405 005 and one of our friendly members of staff will be more than happy to help.