A large-span prestressed main girder gantry crane

Abstract

The present invention relates to a lifting device, particularly a long-span prestressed main girder gantry crane, which includes a prestressed main girder, end beams, anti-rust and anti-flying anchor sleeves, cross braces, a lifting trolley, legs, a lower cross beam, and a trolley traveling mechanism. The prestressed main girder is installed on the legs, the ends of the two main girders are connected by the end beams, and a cross brace for preventing side bending is installed above the main girders. The anti-rust and anti-flying anchor sleeves are installed on the end faces of the prestressed main girders, the lower cross beam is installed at the bottom ends of the legs, and the trolley traveling mechanism is installed on the lower cross beam to enable the longitudinal movement of the crane. The lifting trolley is installed on the transverse movement track on the main girder to complete the lifting operation. The main girder is composed of a rectangular beam and a prestressed arch frame, and is assembled in segments, which is convenient for transportation and assembly, and has a simple and economical structure. The present invention adopts a prestressed main girder, fully utilizes the tensile strength of high-strength steel strands, makes up for the technical blank of large-tonnage prestressed steel structures, has a light self-weight and a low cost, and can meet the market demand for long-span gantry cranes at stations and wharves.

Description

Technical Field

[0001] The invention relates to a lifting device, in particular to a large-span prestressed main beam gantry crane. Background Art

[0002] Patent document CN201610718338.X discloses a gantry crane main beam that utilizes a fish belly cross-section to increase the load-bearing capacity of the crane main beam. However, this device has the following disadvantages:

[0003] 1. The main beam is welded from ordinary steel structure without preset anti-arch. When it is used for large-span gantry cranes, its section stiffness requirements become higher, thus requiring a higher section and larger plate thickness.

[0004] 2. The main beam has low vertical stiffness and large downward deflection, which causes the crane trolley to climb a large slope.

[0005] 3. This type of main beam is only suitable for small and medium-span gantry cranes. If it is extended to be used as a main beam for large-span gantry cranes in scenarios such as railway freight yards and ports, the amount of steel used must be increased to meet the requirements of stiffness and strength, and it no longer has the advantage of low manufacturing cost. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a large-span prestressed main beam gantry crane with high rigidity, few consumables, low cost, simple structure, and easy assembly, which can be suitable for railway freight yards, ports and other large working scenarios.

[0007] The present invention is achieved through the following technical solutions:

[0008] A large-span prestressed main beam gantry crane includes a prestressed main beam, an end cross beam, an anti-rust and anti-flying anchor sleeve, a cross-connecting frame, a lifting trolley, a transverse track, an outrigger, a traveling trolley and a trolley operating power mechanism. The two ends of the prestressed main beams are first connected by an end cross beam, and then the prestressed main beams are installed as a whole on the top of the outriggers, and a cross-connecting frame for preventing lateral bending is installed above the prestressed main beams. The anti-rust and anti-flying anchor sleeves are installed on the end face of the prestressed main beam, and the traveling trolley is installed at the bottom end of the "herringbone" outrigger. The trolley operating power mechanism is installed on the traveling trolley to drive the crane to move longitudinally. The lifting trolley is installed on the transverse track on the top surface of the main beam to complete lifting and transverse operations.

[0009] The prestressed main beam is a composite beam composed of a rectangular beam and prestressed arches. Prestressing is applied after segment assembly. The prestressed main beam design incorporates a moderate upward arch, cleverly increasing the rigidity of the crane's main beam and significantly saving material. The prestressed main beam is the core technology of this invention, while the prestressed arch tensioning is its technical innovation.

[0010] The prestressed main girder is a prestressed steel structure beam.

[0011] The prestressed main girder is a prestressed concrete-filled steel tube beam.

[0012] The prestressed main girder is a combined beam of prestressed concrete beam and steel beam. The main girder composed of prestressed rectangular beams and prestressed arch frames gives full play to the material properties of concrete in compression and steel strands in tension. Tensioning the rectangular beam makes each section integrated and increases the tensile strength of the upper flange of the rectangular beam; using appropriate prestressed arch frame tensioning offsets the upward camber generated by the tensioning of the prestressed rectangular beam.

[0013] Regarding the number of the prestressed main girders, when the lifting weight is small and the span of the gantry crane is small, there is 1 prestressed main girder; when the lifting weight is large and the span of the gantry crane is large, there are 2 prestressed main girders, and multiple cross-linking frames are arranged between the 2 prestressed main girders to connect the 2 prestressed main girders into a whole and prevent instability side bending caused by tensioning.

[0014] The prestressed main girder is assembled in segments, and the segment lengths of the rectangular beam and the arch frame are determined accordingly according to the main girder span and transportation requirements.

[0015] Regarding the tensioning method of the prestressed main girder, when the lifting weight is small and the span of the gantry crane is small, only the arch frame of the prestressed main girder is tensioned to meet the stiffness and strength of the main girder; when the lifting weight is large and the span of the gantry crane is large, the arch frame and the steel box concrete composite beam of the prestressed main girder are tensioned simultaneously to meet the stiffness and strength of the main girder.

[0016] The prestressed steel strands of the prestressed main girder are tensioned with double anchor devices to prevent the steel strands from slipping and the wedge jaws from flying off.

[0017] An anti-rust and anti-flying anchor sleeve is arranged at the end face of the prestressed main girder to prevent the corrosion of the steel strands and the flying off of the wedge jaws.

[0018] Regarding the installation position of the hoisting trolley, when the lifting weight is small and the span of the gantry crane is small, the hoisting trolley is of the under-hung type, that is, the running track of the hoisting trolley is installed at the bottom of the rectangular beam of the prestressed main girder; when the lifting weight is large and the span of the gantry crane is large, the running track of the hoisting trolley is installed on the top surface of the prestressed main girder, and the steel wire ropes and the hook are placed between the two prestressed main girders for hoisting operations.

[0019] The following further elaborates on the present invention in conjunction with the attached drawings. Description of the Drawings

[0020] Figure 1 It is a three-dimensional view of the structure of the gantry crane with a large-span prestressed main girder of the present invention.

[0021] Figure 2It is the side view of the long-span prestressed main girder gantry crane described in the present invention.

[0022] Among them: 1. Prestressed main girder; 2. End cross beam; 3. Rust and flying anchor prevention sleeve; 4. Cross connection frame; 5. Lifting trolley; 6. Leg; 7. Lower cross beam; 8. Crane travel mechanism. Specific implementation mode

[0023] As Figure 1 、 Figure 2 shown, a long-span prestressed main girder gantry crane described in the present invention is a gantry crane with a combined prestressed steel structure beam of a steel box girder and an arc steel pipe arch with a span of 100m, a lifting capacity of 32t, and a height of 20m, including a prestressed main girder 1, an end cross beam 2, a rust and flying anchor prevention sleeve 3, a cross connection frame 4, a lifting trolley 5, a leg 6, a lower cross beam 7, and a crane travel mechanism 8. The prestressed main girder 1 is installed on the leg 6, the ends of the two main girders are connected by the end cross beam 2, and a cross connection frame 4 for preventing side bending is installed above the main girders. The rust and flying anchor prevention sleeve 3 is installed at the end face of the prestressed main girder 1, the lower cross beam 7 is installed at the bottom end of the leg 6, and the crane travel mechanism 8 is installed on the lower cross beam 7 to enable the longitudinal movement of the crane. The lifting trolley 5 is installed on the transverse movement track on the main girder to complete the hoisting operation.

[0024] In this embodiment, the two prestressed main girders 1 are connected by the cross connection frame 4 to form a whole, preventing the side bending caused by tension instability.

[0025] The prestressed main girder 1 described in this embodiment is suitable for the situation where the lifting weight is large and the span of the gantry crane is large. Therefore, two prestressed main girders 1 are set, that is, a combined beam composed of a rectangular steel box girder and a prestressed arc steel pipe arch. After the two combined beam segments are assembled, synchronous prestress tension is applied to the arc steel pipe arch. The prestressing tendons of each arch are composed of multiple steel strand bundles to establish prestress and create an appropriate upward camber.

[0026] The prestressed steel strands of the prestressed main girder 1 described in this embodiment are tensioned with double anchor devices to prevent the steel strands from slipping and the wedge grips from flying off. A rust and flying anchor prevention sleeve 3 is arranged at the end face of the rectangular steel box girder of the prestressed main girder 1, and it is bolted to the end of the rectangular steel box girder to cover the exposed steel strands and anchor devices, preventing the corrosion of the steel strands and the flying off of the wedge grips.

[0027] The total length of the prestressed main girder 1 described in this embodiment is 100m, and it is assembled in segments. It is divided into 9 segments in total. The lengths of the two end segments are 15m, and the lengths of the remaining segments are 10m to meet the transportation requirements. The rectangular steel box girder is assembled with shear plates, and the arc steel pipe arch is assembled with flange plates.

[0028] The 100m span gantry crane described in this embodiment relies on the technological innovation of prestressed steel structure. Its advantage is that it can replace three 30m span gantry cranes, saving four legs 6, four lower beams 7, four sets of trolley running mechanisms 8 and their tracks, saving a large amount of steel, and having significant social and economic benefits.

[0029] The gantry crane described in this embodiment has a height of 20m. After deducting the main beam height of 5m, the actual clearance height under the main beam is 15m. Considering the lifting angle, a reserved height of 6m is required, and 3 layers of 3m high containers can be stacked, totaling 9m.

[0030] The lifting trolley 5 described in the present embodiment has a lifting capacity of 32t and can lift a 30t heavy container. Its running track is installed on the top surface of the rectangular steel box beam, and the wire rope and hook are placed between the two prestressed main beams 1 for lifting operations.

Claims

1. The gantry crane with a long-span prestressed main girder includes a prestressed main girder, end crossbeams, anti-rust and anti-flying anchor sleeves, transverse connection frames, lifting trolleys, transverse movement tracks, legs, traveling girders and traveling girder running power mechanisms. Among them, the traveling girder includes a lower crossbeam. The ends of the two prestressed main girders are first connected by the end crossbeams, and then the prestressed main girder as a whole is installed on the top of the legs. A transverse connection frame for preventing side bending is installed above the prestressed main girder. The anti-rust and anti-flying anchor sleeves are installed on the end faces of the prestressed main girders. The traveling girders are installed at the bottom ends of the "V-shaped" legs. The traveling girder running power mechanisms are installed on the traveling girders to drive the longitudinal movement of the crane. The lifting trolleys are installed on the transverse movement tracks on the top surface of the main girders to complete the lifting and transverse movement operations; The prestressed main girder is a combined truss girder composed of a rectangular steel box girder and an arc-shaped arch frame. The rectangular steel box girder segments are connected by shear plates, and the arc-shaped arch frame segments are connected by flange plates. After the segments are assembled, the steel strands in the arc-shaped arch frame of the main girder are subjected to overall prestress tensioning to preset an appropriate upward camber for the main girder to offset the gravity deflection, so that the trolley can run smoothly under the self-weight of the main girder and the weight of the lifted object; The prestressed main girder is a double main girder. The running tracks of the lifting trolleys are installed on the top surface of the prestressed main girders. The steel wire ropes and hooks are placed between the two prestressed main girders.

2. The long-span prestressed main girder gantry crane according to claim 1, characterized in that Double anchor devices are provided for the prestress steel strand tensioning of the prestressed main girder.

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