In technology, one of the first world devices was the pulley.
What is a pulley?
Pulley represents a simple device constructed for making the loading and lifting of heavyweight easier. Usually, the Pulleyhas a wheel connected to a shaft and a rope. The three crucial parts of a Pulley are the wheel, axle, and string. The best part of using a Pulley is altering the direction and point of force application, making lifting loads easier.
What is the mechanical advantage of a pulley?
The mechanical advantage of a pulley is equal to the number of ropes supporting the movable load. For example, with a two-wheel pulley, the user lifts the weight with half the force because it reduces the effort you exert to lift the same weight.
How does a pulley work?
A pulley with one wheel works as a device that allows you to reverse your lifting force’s direction by pulling down on a rope and lifting weights. With a two-wheel pulley, the user lifts the weight with half the force because it reduces the effort you exert to lift the same weight.
How does a pulley make work easier?
Pulley makes work easier because the pulley system makes it easier to lift an object than lifting the dead weight by hand, reversing your lifting force’s direction by pulling down on a rope. So, the pulley reduces the force needed to lift an object. To lift something four times heavier using a pulley, you can use the same force, but only if you pull the rope four times further.
What are the parts of a pulley system?
The three different parts of a Pulley are the wheel, axle, and string. A pulley consists of a rope and a hub or “drum” in which there is a grooved wheel mounted with an axle. A pulley system is a tensioning system that comprises several pulleys (block and tackle), a rope, a rope brake, an ascender, and connectors.
The system wheel consists of deep groves to keep the rope still in its place without slipping. Also, the rope’s tension is maintained on both sides to balance the lifting and avoiding failure. The wheel moves on the shaft to facilitate the lifting. A “key” puts the shaft and wheel attached. The malfunctioning of the key can dissolve the system within fractions of a second.
Here in this video below, we can see parts of the pulley:
What are the types of Pulley?
Based on how the parts are attached, there are several types of PulleyPulley.
Fixed Pulley
The grooved wheel is fixed to the axle, and the entire apparatus is attached to the ground. The device of such type can only change the direction of the force applied. It cannot change the movement and amount of force for lifting. Therefore, this type of PulleyPulley is of limited utility.
A movable Pulley
A movable pulley has a wheel attached to a shaft, and the rope is fixed on one side only. This implies while pulling, the force is reduced, and the axle is free to move. This type of pully is of high utility in lifting heavyweights.
Compound Pulley
As the name suggests, the compound pulley is a combination of the above two types of PulleyPulley. It reduces the force to half of the weight to be lifted by the setup.
Block & Tackle Pulley
This is a giant pulley where many pulley systems are combined for weighty lifting. The system employs all the parts for maximum reduced effort in pulling heavy loads like trucks, ships, etc. It is believed that this type of PulleyPulley was first developed during the world war by Archimedes. The construction uses all the parts of the Pulley optimally for efficient lifting. This is used in industrial processes and on ships for lifting heavy loads of items.
These are used in cranes, automobile factories, aerospace, and rescue in different disasters. It’s the simplest yet boldest creation in history for reducing human effort in lifting heavy objects.
How to make a pulley system to lift heavy objects?
To create a pulley system to lift heavy objects, you need to buy Lifting Wheel Fixed Pulley for Wire Rope Loading 400kg, which is cost around $10. When you create a pulley system to lift heavy objects for each wheel and rope you add, you will have to pull double the rope to raise the object to the same height as you would with one rope. As a trade-off, you will need half the amount of energy to hoist the object. For example, if you raise a weight of 100kg (1000 newtons) at a distance of 1 meter off the ground, you have to do the same amount of work whether you use a pulley or not: you have to move the same force over the same distance.
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