13 Nov, 2019

What is Pulley? 

This blog is aimed at informing anyone who deals with pulley about various pulley facts and things that they should know about.

In our everyday life, we come in contact with myriads of simple machines and leverage those in numerous ways for our convenience. Starting from a doorknob to blind on windows, elevators to gym or exercise machines, all such things make extensive of the pulley system. The concept of the pulley was discovered centuries ago, and pulley uses are in practice since then. Pulley facts like these are not known by many and hence it is important to know about them.

To define it briefly and clearly, a pulley is a simple metallic or wooden machine primarily used to lift heavy loads with the help of a wheel and a cable. The wheel is specifically designed to support and increase movement, and it changes the direction of a force in order to aid someone in lifting heavy loads or weights upwards. The driving component of a pulley system is the rope or cable or belt. A pulley generally has a narrow channel or groove to help locate the rope or cable, which eventually facilitates lifting things up in a hassle-free way effectively.

Different types of pulleys  

Pulleys are of primarily three types – single pulley, movable pulley, and compound pulley.

Fixed Pulley

The wheel and axle of a fixed pulley stays fixed in one position. Mainly attached to a supporting structure, a fixed pulley has a shaft mounted in bearings.

Movable pulley

A movable pulley can be easily pulled upwards and downwards. It has an axle in a movable block. Two parts of the same cable support a single movable pulley. It is easier to lift loads effectively by using a movable pulley, as it has a mechanical advantage of two.

Compound pulley

A compound pulley is a combination of both the fixed and movable pulley that forms block and tackle. Myriads pulleys are mounted on the fixed and moving axle of a block and tackle that aids in fostering the mechanical advantage.

However, compared to a fixed pulley, a pulley manufacturer knows precisely that a movable pulley provides a significant mechanical advantage that determines the efficiency and productivity of a machine. Mechanical advantage implies that the force exerted by the machine is greater than the manual force. Due to this great advantage, it becomes easier to lift a heavy object with force than the one applied to the cable.

Reading the pulley facts to choose the right pulley for your industry

In order to choose the right pulley for your industry and seamlessly accomplish required tasks, you need to be well aware of the pulley manufacturers and pulley exporters in the market that are reputed and manufacture quality products that cater to different industries effectively.

Before choosing and purchasing a pulley, ensure that all the parts of the pulley meet top-level quality assurance standards and efficient enough to render excellent performance consistently.

Difference between idler pulley and drive pulleys 

Drive pulley-

A drive pulley is one type of pulley that is attached to a power source, which, when functions, exert force on the cable or belt. The cable is connected to the material that is required to be driven and will lead to a spin. In this way, the transmission of power takes place.

Idler pulley-

Similar to drive pulleys, idler pulleys are also primarily made up of metals or woods. It comprises two major components – a round disk and a centre hole. This type of pulley is used as engine pulley, mainly responsible for driving and creating tension in the engine belts.

How to maintain pulleys block and parts?

  • Inspect the wheel and make sure that it works properly by spinning it several times.
  • Apply lubricant between the wheel and the side plate to ensure that it spins perfectly.
  • Make sure that there are no big tear and wear at the blocks that hold the blocks together.
  • Consider replacing the pulley, if you find any issues in the hook.
  • Try to make use of a bridge pin and snatch pin of optimum size.
  • Apply quality lubricant on the wheel for efficient pulley uses.
  • Ensure that the block or the wheel and the cable are properly aligned to eliminate side loads.

Why are pulleys use in power transmission?

Specifically designed to spin with a shaft, a driver pulley draw the power from the motor that is rotating the shaft and transferring it to other pulleys through the shared cable. The output of the machine can be improved by changing the size of the drive pulley. During power transformation, idler pulleys, which are also known as backside idlers and tensioners, play essential roles. By engaging the mower deck, you lower the idler blades close to the ground and at the same time, press the backside idler or tensioner into the cable. The cable or the belt adjusts itself into the narrow space or groove of v-grove idler pulleys. The tighter it seats itself into the trough, the better is the transmission of power occurs.

Pulleys dimension definitions

  • Flanges – This is one of the pieces that stick out and away from the flat idlers of the pulley. Most pulleys usually have two flanges.
  • Set screw holes – Set screws holes on the drive pulley are used to tighten the pulley to avoid it, making any upwards or downwards movement.
  • Teeth – Teeth can be found in numbers on the timing pulley.
  • Back Side Offset – It is typically considered to the shorter portion of the through bore.
  • Bearing ID – It is the bearing used in the inside diameter of the idler pulley.
  • Belt Length – The measurement from around the belt is called belt length.
  • Belt width – The total width of the belt or cable of the pulley is called belt width.


While there are many pulley facts and things that matter when choosing the perfect fit for your requirement, they need to be made of the right quality materials in order to efficiently serve the required purpose.

Professionals at Shree Shakti Pulleys have years of experience and competency to ensure and provide high-quality pulleys that duly meets all requirements in an effective and seamless way.

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