A pulley is an easy mechanical tool with a flexible rope, cord, chain, or belt carried on the wheel rim. Any size and length are acceptable for the wheel and rope. The wheel is also known as a sheave or a drum. Pulleys come in a variety of designs and serve a variety of functions. Tell us about the numerous pulley types.
A range of lifting and moving operations are made simpler by different types of pulley. These are categorized based on changes in force direction, changes in force magnitude, and changes in both force and magnitude. The rope, wheel, and axle that the grooved wheel is mounted with make up the pulley system. Let’s talk in depth about the many sorts of pulleys in this article.
Well, in this article we will be talking about the Types of pulleys and their working, where by the answers to the following question will be discussed:
- What is Pulley?
- What are the Advantages and Disadvantages of Pulley?
- What are the Types of Pulleys?
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Contents
What is Pulley?
A pulley is a mechanical tool used to lift heavy objects made up of a wheel, rope, belt, or chain. The pulley’s wheel typically revolves on an axle or shaft and is fixed to a hinge. Chain, rope, belt, or cable serves as the driving element that passes over the wheel in an easy pulley setup. The object is loaded at one end of the rope, and when the rope is pulled down, the thing lifts from that end. A set of pulleys is used to raise heavy objects.
These are also used for power transfer between rotating shafts. The usage of pulleys has the benefit of allowing big things to be raised with only a little force. In other words, the pulleys increase the force in order to raise big objects that cannot be lifted by hand alone.
What are the Advantages and Disadvantages of Pulley?
Advantages:
The biggest benefit of using pulleys is that it requires less work than simply lifting weights normally. To put it another way, it lessens the real force needed to raise large objects. Additionally, the force’s direction is changed. Because of these two benefits, pulleys are a crucial instrument for heavy lifting. Additionally, it offers a mechanical benefit.
Another benefit of using pulleys is that there is a safe distance between the operator and the weight, preventing any accidents. Pulleys are simple to put together and economical. The combination of different directional pulleys can change the position of the load with little effort. Though the pulley system has moving parts, they require little to no lubrication after installation.
Disadvantages?
In addition to the above benefits of adopting pulley systems, there are also certain disadvantages. The pulley system’s primary disadvantage is that it takes up a lot of room to install and run. Pulleys have a higher mechanical advantage but require more installation space.
In some situations where the ropes or belts pass over the wheel without grooves, it is expected that the ropes or belts will slip from the wheel. As the friction between the wheels and cables/ropes occurs, causing wear and tear on them, systems that are installed to be used for a long time require maintenance and regular checking of the ropes/cables. The ropes get weak when the system is used frequently. While employing the technique, the rope could break, damaging the operator, the surrounding area, and the load being hoisted.
What are the Types of Pulleys?
There are eleven major types of pulleys, namely, Fixed pulley, Movable pulley, Compound pulley, Block and tackle pulley, Step pulley, “V” groove pulley, Cone pulley, Jockey pulley, Round pulley, Fast and loose pulley, Conveyor pulley.
Fixed pulleys are ones that have only one point of attachment. As the name implies, the rope or chain goes through this pulley, which is fastened to a wall or other support and is immovable. These are essential mechanical mechanisms since they shift the object’s direction, which is very beneficial.
- Fixed pulley
- Movable pulley
- Compound pulley
- Block and tackle pulley
- Step pulley
- “V” groove pulley
- Cone pulley
- Jockey pulley
- Round pulley
- Fast and loose pulley
- Conveyor pulley
Compound pulley
A compound pulley, for example, is made up of fixed and movable pulleys that make the weight lighter and allow you to adjust the force’s direction. These types of pulleys are good for really big loads, but you may need a lot of speed to complete the task properly.
It’s made to ensure that the effort you’re putting in is less than half of the actual load. These devices are commonly used on construction sites and on cranes that hoist large materials like concrete and steel. A combined pulley system is another name for it.
Block and tackle pulley
A block and tackle pulley is a mechanism that uses rope or cable to connect two or more pulleys to raise heavy loads. These pulleys are stacked in a block and then connected such that one is stationary and the other moves with a load. The rope is threaded into the pulley to provide a mechanical advantage, which increases the force delivered to the rope. These pulleys are commonly employed to raise enormous weights or to impart a large amount of force in either direction.
Fast and loose pulley
These types of pulleys are used for machines that need to be started or stopped quickly. These are two little pulleys that are mounted on a counter shaft in pairs. A ‘key’ or some other medium is used to tighten one pulley on the counter shaft, while another pulley is inserted through a provision for free rotation.
The belt is installed on the tight pulley when the machine is to be operated. A quick pulley is a name given to this type of pulley. The belt is slipped onto the independent pulley, also known as a loose pulley when the machine is to be turned off. Its key advantage is that we may turn off the machine while the main shaft, which is powered by an electric motor or an oil engine, continues to rotate. The belt can be slipped using a lever.
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Conveyor pulley
These types of pulleys are used as a driving pulley on the counter shaft of machines that have a single electric motor or oil engine, as well as a single counter shaft. Their faces are constructed to be as large as possible, and they wear flat belts.
A conveyor pulley is used in the conveyor system to help shift the conveyor belt’s direction, operate the belt, and supply tension to the belt. Rolling shells with flexible end discs and locking assembly make up these. They are mounted on a motor at one end of the conveyor or adjacent to it.
Step pulley
This type can be described as a collection of pulleys. The faces of the pulleys are fashioned into step pulleys, with pulleys of various diameters fixed in the order. A stepped pulley gets its name from the fact that it looks like a set of steps.
It’s employed in situations where the driven pulley’s speed needs to be increased or decreased for various duties, such as drill machines and lathe machines. They’re frequently used in pairs.
“V” groove pulley
On the face of this pulley, a groove in the shape of the English letter “V” has been cut. Electric motors and vehicles both use it. With these pulleys, a specific “V” shaped belt is needed. More than one “V” groove is cut in some pulleys. These pulleys are utilized for power transmission in heavy-duty applications. There are fewer risks of power slip when more than one “V” belt is used.
Cone pulley
These types are tapered and utilized in a pair of two pulleys (pairs). On two pulleys, a comparable taper is carved. These are connected in such a way that the large end of one is opposite the small end of the other, causing a shift in speed as the belt moves. We can acquire adequate speeds for various jobs with the help of this pulley.
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Fixed pulley
The rope is tied to the object and the pulley is attached to a fixed location in this form of pulley system. The fixed pulley’s wheel and axle are designed to fit together. It is made out of a single drum that is attached to a single location.
One side of the rope is pulled downwards, while the other is pulled upwards. You pull it down with the same force as if you were lifting the object by hand. However, the force’s direction is altered. This is advantageous since you can push with your own body weight when you draw down.
Movable pulley
The rope is attached to the fixed point and the other end of the rope is left free in this type of pulley. The thing that has to be moved is hooked to the pulley. The rope moves when you pull it, and the pulley lifts the object. This approach is ideal for elevating an object that is underneath you to a higher level.
Because the object can travel along the rope if a force is given to it, the system works like a wheel and axle if both sides of the movable pulley system are fixed and the rope is stretched between fixed locations.
Jockey pulley
One issue that frequently arises when using these pulleys is that their belts get loose and slip over time, resulting in a loss of power. A third pulley is utilized with the pair of two pulleys to solve this problem, as illustrated in the diagram. It’s known as a jockey pulley. This pulley is a self-regulating pulley that tightens the belt when it loosens.
Round pulley
On the face of this sort of pulley, around the groove is carved. It is controlled by round belts or ropes. It can also be manufactured in the same way as a step pulley.
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A word From Student Lesson
A pulley is a basic mechanical device that consists of a flexible rope, cord, chain, or belt that is supported on a wheel’s rim.
Well, that is all for this article where we talked about Types of pulleys and their working, where we also answered the following question:
- What is Pulley?
- What are the Advantages and Disadvantages of Pulley?
- What are the Types of Pulleys?
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