The Comparison Of Port Single Boom Portal Crane And Four-bar Portal Crane

Gantry cranes can be divided into two types: four-bar linkage composite boom gantry crane and single boom gantry crane. Among them, the self-weight of the four-bar linkage gantry crane is lighter than that of the single boom gantry crane, because the four-bar linkage gantry crane has more pairs of rods and elephant nose beams than the single boom gantry crane. Therefore, in terms of cost, the four-bar linkage gantry crane is more expensive than the single boom gantry crane. The four-bar linkage gantry crane lifts the rated lifting capacity throughout the process. Some of them switch the lifting gearbox in the second half of the process and change the transmission ratio to lift a larger tonnage. In addition, when the amplitude changes, the horizontal height of the lifted object does not change. The lifting curve of the single boom gantry crane is a straight line that is inversely proportional to the amplitude and lifting weight. The larger the amplitude, the smaller the lifting weight. In addition, the horizontal height of the lifted object changes with the amplitude. When the lifting is not moving, the larger the amplitude, the lower the object, and the smallest amplitude, the highest position of the object. In other words, the biggest advantage of the four-bar linkage gantry crane is that the net height under the boom is large, so that the total height of the crane is lower under a certain lifting height requirement, but its structure is complex and heavy, while the single boom gantry crane is opposite.