How much do you know about gantry crane?
Gantry crane is a kind of deformation of the bridge type crane. It is mainly used for outdoor cargo yard, material yard cargo and bulk cargo handling operation.Its metal structure is like a portal frame. Under the main beam, two supporting feet are installed, which can directly walk on the track on the ground, and the two ends of the main beam can have extended cantilever beams.The gantry crane has the characteristics of high utilization rate, large scope of operation, wide adaptability and versatility, and is widely used in port freight yard.
Classification of gantry crane
According to the gantry frame structure
- Full gantry crane: the main beam is not suspended, and the trolley is carried out in the main span.
- Semi gantry crane: the leg is low and high, which can be determined according to the civil requirements of the site.
- Double cantilever gantry crane: the most common form of structure, the force of its structure and the effective use of the site area are reasonable.
- Single cantilever gantry crane: this type of structure is often chosen because of the limitation of the site.
According to the structure of main gantry
The structure use I-steel welded together, has the advantages of low cost, light weight, good wind resistance. However, due to the lack of welding points and the defects of the truss, the trussed beam also has the disadvantages of large deflection, small rigidity, low reliability and frequent detection of solder joints. Applicable to a site with lower safety requirements and smaller weight.
Use welded steel box type structure, has the advantages of high safety, rigidity etc. Generally adopt large tonnage and ultra large tonnage gantry cranes. The box girder also has the disadvantages of high cost, self important and poor wind resistance.
According to the structure of main girder
Single girder gantry crane has the advantages of simple structure, convenient manufacture and installation, its quality is small, use the partial rail box frame structure. Compared with the double girder gantry crane, the overall stiffness is weaker. Therefore, when the weight is Q = 50t, S = 35m span, can use this form. There are two forms of single girder gantry crane, L type and C type. The manufacturing and installation of the L type is convenient, the force condition is good, and the quality of its own is small, but the space of the lifting goods through the leg is relatively small. The foot of the C type is made into a sloping or curved shape, with the aim of having a larger lateral space to enable the goods to pass through the foot smoothly.
The double girder gantry crane has strong bearing capacity, large span, good overall stability and many varieties, but the quality is large than the single girder gantry crane with the same lifting capacity, the cost is also high. According to the structure of the main beam, it can be divided into two forms, box girder and truss. Generally, we often choose the box structure.
Safety protection of gantry crane
- Overloading limiter.
- High quality, long time use, impact resistant polyurethane buffer.
- Crane travel limit switch.
- The protection of the loss of pressure and the protection of the wrong phase.
- Emergency parking system.
- Lifting height limit device.