Crane Pulley and crane pulley block
The crane pulley is a small wheel that has a groove around and can rotate around the axis. It is made up of a simple machine that can be rotated around the central axis by a disk that can be grooved around the central axis and a flexible cable that spans the disk. pulley. The crane pulley block is a simple machine assembled from a plurality of movable crane pulleys and fixed pulleys, which can save labor and change the direction of force. The labor saving of the pulley block is determined by the number of rope strands, and the mechanical efficiency is determined by the gravity of the pulled object, the gravity of the moving crane pulley and the friction, and the power is not saved.
More and more moving crane pulleys are combined, but more rope is needed. In fact, the more the combination, the more friction, and the waste of materials, the specific situation is analyzed. The pulley block has the function of saving labor and changing the direction of the force, and is an important part of the lifting machine. Usually the name of the crane pulley block is represented by the number of fixed and movable pulleys of the pulley block.