As Pulley is a type of simple machine it helps to reverse the direction of lifting force. When one end of the rope is pulled downwards, the load on the other end of the rope is pulled upward. Therefore, the direction of force is changed from downwards to upwards. Pulley can work on one, two and four wheels.
The theory of operation for a pulley system assumes that the pulleys and lines are weightless, and that there is no energy loss due to friction. The more pulleys, the easier it is to pull or lift an object. If pulley involved is more, the greater distance to pull, is still easier to lift an object. We have a quality perfect and inextensible pulley tied around the groove where one end is fixed to fixed support while the other end is kept free to apply the effort. As the effort is applied, the block together with the load moves upward.
The working concept of a pulley revolves around the transference of both force and motion through the integration of a belt or rope system that wraps around a wheel. Essentially, a pulley provides a means for either a change in direction of a transmitted force and for the transference of effective power from one power transmission shaft to another. Pulleys are frequently incorporated in industrial applications to effectively translate motion to industrial power equipment by using belts along with another pulley that transmits power at that location in the mechanical apparatus.
For example, motion and power are passed along from a driving pulley to a driven pulley when they both wrap around the same belt to operate equipment in an effective and safe way that helps save money, time and energy.
The most popular and readily used industrial applications that effectively leverage pulleys include conveyor belt assemblies that utilize these wheels to promote efficient material handling in manufacturing factories, mining facilities, and farming machines and apparatus. They feature robust building, are built to endure lasting performance and also provide dependable, safe work without high levels of maintenance or energy reduction.
Fixed And Moving Pulleys
- A Fixed Pulley:
- A Moving Pulley:
The pulley which is made free to move up and down along with the load, it is called a Movable Pulley. It can rotate like fixed pulley and is supported by two parts of the same rope and has a mechanical advantage of two.
Hence, we can say that a single fixed pulley can be used to change only the direction of the applied force whereas a movable pulley can be used to decrease the input force required.
