Gantry cranes can be classified according to the door frame structure form, according to the main beam form, according to the main beam structure, and according to the use form.
By door frame structure
It is divided into gantry crane and cantilever gantry crane
1. Gantry crane
1). Full gantry crane: the main beam has no overhang, and the trolley is carried out within the main span.
2). Semi-gantry crane: the outriggers have a height difference, which can be determined according to the civil engineering requirements of the site.
2. The cantilever gantry crane
1). Double cantilever gantry crane: the most common structural form, the force of the structure and the effective use of the site area are reasonable.
2). Single cantilever gantry crane: This structural form is often selected due to the limitation of the site.
According to the form of the main beam
1. Single main beam
The single girder gantry crane has a simple structure, easy manufacturing and installation, and its own quality is small, and the main beam is mostly a deviating rail box frame structure. Compared with the double girder gantry crane, the overall stiffness is a little weaker. Therefore, when the lifting capacity Q≤50t, span S≤35m, this form can be adopted. The door legs of the single girder gantry crane are available in two forms: L-type and C-type. The manufacturing and installation of the L-type is convenient, the stress situation is good, and its own mass is small, however, the space at the place where the lifting goods pass through the outrigger is relatively small. The C-shaped legs are made inclined or curved in order to have a large lateral space for goods to pass smoothly through the legs.
2. Double main beams
The double girder gantry crane has strong carrying capacity, large span, good overall stability and many varieties, but its own quality is larger than that of the single girder gantry crane with the same lifting capacity, and the cost is also higher. According to the different main beam structure, it can be divided into two forms: box beam and truss. Generally, the box-shaped structure is mostly adopted.
According to the main beam structure
1. Truss beam
The structural form welded by angle steel or I-beam has the advantages of low cost, light weight and good wind resistance. However, due to the many welding points and the defects of the truss itself, the truss girder also has the shortcomings of large deflection, small stiffness, relatively low reliability, and the need to frequently detect the solder joints. It is suitable for sites with low safety requirements and small lifting capacity.
2. Box girder
The steel plate is welded into a box-type structure, which has the characteristics of high safety and high rigidity. It is generally used for large tonnage and super large tonnage gantry cranes. MGhz1200, with a lifting capacity of 1200 tons, is the largest gantry crane in China, and the main beam adopts a box girder structure. At the same time, the box girder also has the shortcomings of high cost, self-weight, and poor wind resistance.
3. Honeycomb beams
Generally refers to the "isosceles triangle honeycomb beam", the end face of the main beam is triangular, there are honeycomb holes on both sides of the oblique abdomen, and there are chords in the upper and lower parts. The honeycomb beam absorbs the characteristics of the truss girder and the box girder, and has greater stiffness, less deflection and higher reliability than the truss girder. However, due to the use of steel plate welding, the self-weight and cost are slightly higher than that of truss beams. It is suitable for sites or beam yards with frequent use or large lifting capacity. Since this beam type is a patented product, there are fewer manufacturers.
By the form of use
1. Ordinary gantry crane
Rail gantry crane
This kind of crane mostly adopts box type and truss type structure, and is the most widely used. It can handle all kinds of finished items and bulk materials, with a lifting capacity of less than 100 tons and a span of 4~39 meters. The ordinary gantry crane with a grab has a higher working level. Ordinary gantry cranes mainly refer to hook, grab, electromagnetic, hoist gantry cranes, but also include semi-gantry cranes.
2. Gantry crane for hydropower station
It is mainly used for lifting and opening and closing the gate, and can also be installed. The lifting capacity is 80~500 tons, and the span is small, 8~16 meters; The lifting speed is low, which is 1~5 m/min. Although this kind of crane is not often lifted, once it is used, the work is very heavy, so the work level should be appropriately improved.
3. Shipbuilding gantry crane
It is used for the assembly of the slipway hull, and there are always two hoisting trolleys: one with two main hooks, which runs on the track of the flange on the bridge; The other had a main hook and an auxiliary hook and ran on rails on the lower flange of the bridge in order to flip and lift large hull segments. The lifting capacity is generally 100~1500 tons; span up to 185 meters; The lifting speed is 2~15 m/min, and there is a fretting speed of 0.1~0.5 m/min.
4. Container gantry crane
Used in container terminals. The trailer will carry the quay wall container to the container unloaded from the ship rail gantry crane
After being transported to the yard or rear, it is stacked by a container gantry crane or directly loaded and transported, which can speed up the turnover of the container carrier bridge or other cranes. The yard that can stack containers with 3~4 layers high and 6 rows wide is generally made of tire type, and there are also rail type. Compared with the container straddle truck, the container gantry crane has a larger span and the height on both sides of the gantry. In order to meet the transportation needs of the port terminal, the working level of this crane is higher. The lifting speed is 8~10 m/min; The span is determined by the number of container rows that need to be crossed, and the maximum is about 60 meters, corresponding to the lifting capacity of 20 feet, 30 feet and 40 feet long containers is about 20 tons, 25 tons and 30 tons respectively.