The gantry crane is a variant of the bridge crane. In ports, it is mainly used for outdoor cargo yard, stock yard cargo, and bulk cargo loading and unloading operations. The form and structure of the main beam determines its specific type. According to the number of main beams, it can be classified into single-beam bridge and double-beam bridge; according to the structure, it can be divided into box structure bridge, steel beam type bridge, and fine-frame type bridge. Each type of structure has different performances. The box-shaped structure bridge is a widely used one. It has the advantages of simple process, convenient assembly, strong applicability, good torsional rigidity and automatic welding. However, the weight is large and the main girder is easy to be lowered. , The horizontal rigidity is poor, the internal welding is not easy, the life of the joint weld between the web and the upper wing is low, and the welding between the transverse stiffening plate and the upper flange plate is easy to crack.
General gantry cranes are divided into double-beam gantry cranes and single-beam gantry cranes, which are suitable for loading and unloading in open-air warehouses, and can also be equipped with a variety of spreaders for special operations.
The single main beam gantry crane has simple structure, convenient manufacturing and installation, and low quality. The main beam is mostly off-track box frame. Compared with the double main beam portal type, the overall rigidity is weaker.
Overload protection devices can be divided into two types: automatic stop type and comprehensive type according to their functions. According to the structure type, there are two types: electrical type and mechanical type. This product is not easy to work in places with flammable and explosive media. It is also not suitable for toxic substances and operation with ground and control room.
Gantry cranes have the characteristics of high site utilization, large operating range, wide adaptability, and strong versatility. They are widely used in port cargo yards. When the crane driver refuses to lift the object because the object is overweight, the commander should take measures to try to reduce the lifting load, and it is strictly forbidden to strengthen the command of the crane's overload operation.
Crane mainly includes hoisting mechanism and so on. The hoisting mechanism is the basic working mechanism of a crane, mostly composed of a hanging system, which lifts heavy objects through a hydraulic system.