Gantry crane, also known as gantry crane, is a variation of an overhead crane. [1]
The metal structure of the gantry crane is like a portal frame, two feet are installed under the bearing girder, which can walk directly on the track on the ground, and the two ends of the girder can have an overstretched cantilever beam, which has the characteristics of high site utilization, large operating range, wide adaptability and strong versatility, and is mainly used for outdoor freight yards, material yards, and bulk cargo loading and unloading operations. [1]
In April 2014, the world's largest 2,000-ton gantry crane built by Shanghai Zhenhua at BrasFELS shipyard in Brazil was officially put into use.
Introduction to the device
Gantry crane (also known as gantry crane) is a bridge type crane supported on the ground track by the legs on both sides. In terms of structure, it is composed of a gantry, a trolley running mechanism, a hoisting trolley and an electrical part. Some gantry cranes only have outriggers on one side, and the other side is supported to run on the plant or trestle, which is called a semi-gantry crane. The upper bridge of the gantry crane (including the main beam and the end beam), the outriggers, the lower beam and other parts are composed. In order to expand the working range of the crane, the main beam can extend beyond the outriggers to one or both sides to form a cantilever. A crane trolley with a boom can also be used to expand the crane operating range through the pitching and rotation of the boom.
2. Classification and editing of forms
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. [3]
Door frame structure
Gantry crane
Gantry crane
It is divided into gantry crane and cantilever gantry crane
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 use site.
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. [3]
Main beam form
1. Single main beam
Gantry crane
Gantry Crane(3)
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 beam
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 a 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. [3]
Main beam structure
1. Truss girder
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. As shown in the figure on the right, 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 beam
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, smaller 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. [3]
Form of use
1. Ordinary gantry crane
Rail 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
Rail gantry crane
Rail gantry crane
Used in container terminals. After the trailer transports the containers unloaded from the ship to the yard or rear, the container gantry crane stacks them up or loads them away directly, 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. [3]
3. Component editing
Gantry crane structure drawing
Gantry crane structure drawing(11)
According to the industry standard GB/T14406, the gantry crane is mainly composed of the following parts
1. Cylindrical wheels
2. a buffer
3. Block brake
4. Wire rope
5. Lifting hook
6. Driver's cab
7. a reducer
8. Casting pulley
9. Casting reel
10. an electric motor
11. Electronic control equipment[3]
4 means method editing
First, the model standard
Gantry crane
Gantry crane
The gantry crane is represented by the four main elements of the code, rated lifting weight, span and working level.
2. Single girder gantry crane
Its symbols are: MDG, MDE, MDZ, MDN, MDP, MDS.
Such as: MDN - single girder, single trolley, grab bucket, hook gantry crane;
MDS-Single girder trolley three-purpose gantry crane.
3. Double girder gantry crane
Its symbols are: MG, ME, MZ, MC, MP, MS.
Such as: MG - double girder single trolley hook gantry crane;
ME-Double girder double trolley hook gantry crane. [3]
5. National standard editing
National Standard of the People's Republic of China GB/T14406-93 General Gantry Crane
1 Main content and scope of use
This standard stipulates the classification, technical requirements, test methods and testing rules of general gantry cranes.
This standard applies to general gantry cranes (hereinafter referred to as cranes) operating in the open air, and their fetching devices are hooks, grabs or electric suction cups (lifting electromagnets), or two or three of them are used at the same time.
The same and similar parts of the special gantry crane can also be used as a reference.
2 Reference Standards
GB 191 Pictorial Signs for Packaging, Storage and Transportation
GB 699 Technical conditions for high-quality carbon structural steel
GB 700 carbon structural steel
GB 783 Crane Maximum Lifting Capacity Series
GB 985 Basic forms and dimensions of weld grooves for gas welding, manual arc welding and gas shielded welding
GB 986 Basic form and size of groove of submerged arc weld weld
GB 1102 Round strand wire rope
GB 1348 Ductile iron castings
GB 1591 Low alloy structural steel
GB 3323 Radiographic quality classification of steel melt welded butt joints
GB 3811 Code for crane design
GB 4628 Overhead crane cylindrical wheels
GB 4942.2 Protection Rating for Low-Voltage Electrical Enclosures
GB 5905 Crane test specifications and procedures
GB 5972 Practical specification for inspection and scrapping of wire ropes used in hoisting machinery
GB 6164 Crane buffers
GB 6333 Electro-hydraulic block brakes
GB 6334 DC solenoid block brakes
GB 6417 Classification and description of defects in metal melting welds
GB 6974 Noun Terminology for Lifting Machinery
GB 8918 High Quality Wire Rope
GB 8923 Rust grade and rust removal grade of steel surface before painting
GB 9286 Paint and varnish film scratch test
GB 10051 Lifting hook
GB 10095 Accuracy of involute cylindrical gears
GB 10183 Tolerances for overhead and gantry crane manufacturing and track installation
GB 11352 Cast carbon steel parts for general engineering use
GB /T14007 General Purpose Bridge and Gantry Crane Driver's Cab Technical Conditions
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