Ever-Power 

Introduction to pulleys

In mechanics, a typical pulley is a round wheel that can rotate around a central axis. There are grooves on the circumferential surface of the round wheel, the rope is wound around the groove, and either end of the rope is pulled hard, the friction between the rope and the round wheel will cause the round wheel to rotate around the central axis. The pulley is actually a deformable and rotatable lever. The main function of the pulley is to pull the load, change the direction of force, transmit power and so on. A machine composed of multiple pulleys is called a “pulley block” or “complex pulley”. The pulley block has greater mechanical benefits and can pull heavier loads. The pulley can also be a component of a chain drive or a belt drive, which transmits power from one rotating shaft to another.
According to the position of the central axis of the pulley, the pulleys can be divided into “fixed pulley” and “moving pulley”; the central axis of the fixed pulley is fixed, and the central axis of the movable pulley can be moved. Each has its own advantages and disadvantages. The fixed pulley and the movable pulley can be assembled together to form a pulley block, which not only saves effort, but can also change the direction of the force.