Conveyor belts are everywhere, from factories and households to busy airports. They help move material and goods quickly, safely, and efficiently. But have you ever paused to ask how these belts actually move? The answer lies in different types of conveyor belt pulleys. However, understanding all those types of pulleys and their role is crucial.
It helps you see how conveyor belt systems work behind the scenes to keep operations running smoothly. Remember, each type of pulley serves a specific purpose and helps move things. Are you unfamiliar with those types? Worry not! In this article, I will explore some common types of conveyor belt pulleys and what each one does. So, let’s get started!
What are Conveyor Belt Pulleys?
A conveyor belt pulley is a mechanical device that helps move a conveyor belt. It looks and works like a wheel, mainly made of metal. The belt wraps around this wheel. When the pulley turns, it rotates and moves the wrapped belt forward.
Pulleys are an essential part of the conveyor belt. Without them, the belt will not move at all. They are usually placed at the ends and along the length of conveyor belts. Each conveyor belt contains a set of these belts, each performing a specific job. For example, some derive the belt, but some guide and direct it.
Moreover, the size and shape of the pulleys can also be changed depending on the conveyor type. For instance, conveyor belt manufacturers cover some pulleys with rubber. This process is called lagging. It helps improve grip and reduce slipping. This is mainly done for mining conveyor belts.
Main Parts of Conveyor Belt Pulleys
Conveyor belt pulleys do not work alone. A series of components help move the whole conveyor system efficiently. Let’s take a closer look at those parts.
- Shell (Drum): This is the outer cylindrical part of the pulley, where the belt sits or wraps around. Therefore, it is made with strong metal or coated with rubber to improve grip.
- Hub: It is the central part that connects shafts to shells. In this way, it helps transfer motion from the inner part to the outer drum. This movement is crucial to rotate and move the belt.
- Shaft: The shaft is a long solid rod that moves through the center of the pulley. It supports the entire pulley and helps it to spin. Usually, the shaft is held with bearings to ensure minimal resistance and smoothness.
- End Discs: This is the flat round piece at both ends of the drums. This part connects the drum to the hub and distributes the weight and pressure. As a result, it ensures the durability and strength of the conveyor pulley.
- Lagging: Lagging is an optional part. Lagging refers to covering the shell with rubber or other material. It improves the fraction between the pulley and belt and prevents slipping.
Types of Conveyor Belt Pulleys & Their Role
Conveyor belt pulleys are one of the vital conveyor belt components. Behind their efficient work are several pulleys, each performing a specific job. So, let’s dive and explore common types of conveyor belt pulleys and their role.
1- Drive Pulley
The drive pulley is one of the critical types of conveyor system. As the name suggests, it provides the driving force to move the belt. Without a drive pulley, the conveyor belt would sit still and not move. This pulley is mainly connected to an electric motor that provides power. When the motor runs, it turns the drive pulley.
As the pulley rotates, it pulls the belt along. This makes the belt move and carry things from one place to another. Generally, the drive pulley is placed at the head end of the conveyor. That’s why it is also known as the head pulley. However, this location can also be changed depending on the design and need.
2- Tail Pulley
After the drive pulley, it comes to the tail pulley. Instead of powering, this pulley guides the belt as it moves back to the starting point after unloading. That’s why it is also known as a return pulley. It is mainly present at the end, where material first gets loaded. So, it helps guide the return side of the belt.
The primary role of this pulley is to keep tension on the belt. The belt will slip or sag out of the track without proper tension. That tail pulley ensures that the belt remains tight and does not slip. Moreover, you can adjust the tension of this pulley according to the types of conveyor belts.
3- Snub Pulley
It is a smaller conveyor belt pulley located near the drive pulley. This pulley mainly increases the contact area between the drive pulley and the conveyor belt. This extra connection increases friction and helps the drive pulley get a better grip on the belt. More friction means less slippage and a more efficient system.
Remember, the snub pulley does not drive the belt. It just changes the angle at which the belt touches the drive pulley. This angle helps the belt wrap more around the pulley, which increases tension and reduces slippage. Therefore, a snub pulley is usually present at the end of the return side of the convoy system.
4- Take-Up Pulley
The take-up pulley is part of the special take-up system of the conveyor belt. This system may work to control the tension of the conveyor belt. So, take-up pulleys play a vital role in maintaining the conveyor belt’s proper tension. As you know, belts, especially fabric conveyor belts, become loose over time due to heavy loads.
If the belt becomes loose, it might sag or go off the track, which can cause damage and accidents. That’s where the take-up pulley comes in. It is located at the tail and attached to a weight. When the belt starts loosening, it automatically adjusts the tension and tightens it. This ensures the conveyor system’s long lifespan.
5- Bend Pulley
Bend pulley is another support pulley in the conveyor belt system. Its main job is to direct the belt in the right direction. Let me explain its function in more simple words. Usually, conveyor belts move straight from the drive pulley to the tail pulley. But there is not always room for a straight line in some setups.
Here, the belt must go around corners or up and down. That’s where the bend pulley helps it change position. It guides the belt to curve or bend to fit the available space, ensuring proper system alignment. The bend pulley is found just before or after the take-up or near the snub pulley.
6- Guide Pulley
As the name suggests, the guide pulley guides the conveyor belt. It ensures the belt remains on the track and in the correct position while carrying a load. Sometimes, belts start to wander off track due to a heavy load. This is called misalignment. It can damage the conveyor belt and malfunction the entire process.
However, the guide pulley acts as a guardrail and pushes or redirects the belt back to the center path. So, it is mainly located near the edges of the conveyor system, either on the top or bottom. The guide pulleys work with a belt tracking system or sensor in the modern conveyor system. They detect any misalignment of the belt and redirect it automatically.
7- Impact Pulley
An impact pulley is specially designed to absorb shocks and stress. Socks often occur at the loading point during the loading of materials. When heavy objects drop on the belt, they damage the belt and other pulleys. So, an impact pulley absorbs all those impacts and makes the system run smoothly. What makes it special is its shock-absorbing surface.
This surface is made with a thick layer of rubber, which acts as a cushion. When the heavy object hits this surface, the impact pulley below handles it smoothly without getting damaged. In many conveyor systems, an impact pulley is used along an impact idler. These are special rollers with rubber covers that are placed under the belt. They provide extra protection and support to the belt against socks.
8- Flat Face Pulley
It is one of the most common and simple types of conveyor belt pulleys. As the name suggests, it has a flat and straight surface. There are no curves or crowns in the middle of this pulley, so it looks like a straight cylinder. Because of this flat surface, the belt can sometimes slide to the side due to movement.
Other pulleys may redirect the belt with their shape, but flat pulleys cannot. That’s why the system that uses a flat pulley must use an extra helper. Those include guide pulleys or tracking devices that help redirect the belt. Due to this setup, flat pulleys are best for short distances and light-duty or slow-speed systems.
9- Crowned Face Pulley
The crowned pulley is another conveyor belt pulley with a slightly raised shape in the middle. Unlike flat surfaces, the center part of this pulley is a bit higher than the edges. This slight curve is known as a “crown,” which is why it is named so. Basically, this curved surface helps the belt stay in the middle of the pulley.
Typically, when the pulley moves, the belt starts to move one side. But the curved surface of the crowned pulley guides it back to the center. This prevents the belt from sliding off even in heavy loads. Therefore, crowned pulleys are commonly used in systems that run fast or have longer belts.
10- Wing Pulley
Wing pulley is a special conveyor belt pulley that looks different from regular pulleys. Instead of a flat surface, it has a series of metal wings that extend outward from the center. These wings look like cages or ribs, with open spaces between them. This cage or fan-like system provides the pulley self-cleaning. HOW?
When the belt carries material like sand, dirt, or coal, it gets stuck between the pulley and the belt. This can stop the pulley and the entire system. However, in the wing pulley, the angle wings push out the debris through open spaces when the pulley spins. This feature makes the wing pulley ideal for dirty, sticky material and reduces maintenance.
Frequently Asked Questions
Why are pulleys necessary in conveyor systems?
Pulleys are one of the most essential parts of the conveyor belt system. They drive, guide, and support the belt as it carries the goods from one place to another. Without pulleys, the conveyor system will be unable to move and work.
Do all conveyor belts use the same pulley types?
No, not all the conveyor belts use the same pulley types. It depends on the specific needs of the conveyor system. It also depends on the type of material being carried, the belt’s length and the speed of the system.
Are conveyor pulleys easy to maintain?
Yes, conveyor pulleys, especially wing pulleys, are generally easy to maintain. However, like other machinery, they also require regular checks. For example, check for cracks and wear, lubricate, and clean to avoid bigger problems.
What materials are pulleys made of?
Conveyor belt pulleys are mainly made of different metals. Those include aluminium, cast iron, stainless steel, and steel. However, they are sometimes covered with rubber to protect against shocks. This process is called lagging.
Conclusion
In summary, conveyor belt pulleys are an essential part of the conveyor system. They help with the efficient, smooth, and fast operation of conveyor belts. However, not all pulleys are the same. They come in various types, each specific to a definite job. In this article, I have discussed those types and their roles.
For example, drive pulleys are connected with motors and help move the belt. However, some pulleys, such as guides and pulleys, direct the belt to the correct position. Some pulleys have a special texture that prevents the belt from slipping. All these pulleys work together in a conveyor system and help move things from one place to another.