Nowadays, the speed of economic development is getting faster and faster, which directly promotes the development of the engineering construction industry. As one of the main equipments for engineering construction, the crane has more and more work intensity. Under the condition of long-term high-intensity cycle work, it will cause certain damage to the crane itself and various components.double girder gantry crane. This requires us to consider how to reduce the working force of the crane, and the pulley is an important part of the crane component that must be considered.
The main purpose of the crane to use the pulley is to wear the wire rope, change the direction of movement of the wire rope and achieve the purpose of saving labor. According to its different functions, it can be divided into fixed pulleys, moving pulleys, pulley blocks, guide pulleys and so on. In the hoisting operation, if only the fixed pulley is used, the direction of the force can only be changed, and the function of the force can not be saved; the use of the movable pulley can save the force, but the direction of the force cannot be changed. In this way, the fixed pulley and the movable pulley must be connected together to form a pulley block to meet the requirements of the crane operation.
The pulleys are divided into hot-rolled pulleys, cast iron pulleys, cast steel pulleys, nylon pulleys and aluminum alloy pulleys according to their materials. The lifting weight is small, the working level is low, cast iron pulley, nylon pulley and aluminum alloy pulley can be used; the lifting weight is large, the working level is high, the cast steel pulley and the hot rolling pulley are selected; the explosion-proof crane is nylon pulley or aluminum alloy pulley. The choice of pulley material can be considered according to factors such as weight, working level and explosion-proof requirements.
In order to reduce the binding force acting on the wire rope, the diameter of the rope groove on the new pulley is slightly larger than the diameter of the new wire rope, and the pulley on the crane is worn regardless of the material. The different forms of wear on the pulley are related to the condition of use, and the more frequently used, the more severe the wear. Since the condition of the pulley has a great influence on the entire service life of the wire rope, the pulley should be inspected regularly, and the focus of the inspection is the wear of the pulley rope groove.light duty gantry crane
The wear of the pulley is caused by the wire rope being cut into the pulley. When the rope groove is too narrow, the pulley will reduce the service life of the wire rope and reduce the performance of the newly installed wire rope, and the new wire rope will be subjected to great pressure from the radial direction. For high-performance anti-rotation wire ropes, the broken pulley is particularly destructive, and the pressure can cause the wire rope to break or change the structure of the strand in a short period of time, such as wire jump, rope core run out or wave deformation. The damage of the high-performance anti-rotation wire rope can be judged by the difference in length between the core and the outer strand. According to the requirements of ISO4309, this typical damage meets the standard of scrapping. Crane owners can prevent this damage by replacing new pulleys or machining the rope grooves. All used pulleys should be tested before installing new wire ropes. As long as the surface of the rope groove is smooth and the width of the rope groove is larger than the actual diameter of the wire rope, no trimming is required.