The door frame of the door crane is made up of which parts
Vierendeel truss structure similar to partial rail box girders, is composed of four pieces of steel structure of a closed, in addition to the main web for solid abdomen i-section girder, the other three piece of sheet metal in accordance with the design requirements of cutting into many window, form a vierendeel truss without diagonal, in the upper and lower levels of truss surface covered by bedplate, crane running mechanism and electrical equipment installed inside the bridge, weight is lighter, the overall stiffness is large, it is more widely used in China a type.
Partial rail box double beam and rail box single girder cross section are ranged from upper and lower flange plate and the thickness of the deputy of web, rail car is decorated in the main web above, the casing short stiffening plate could save, in which partial rail box single main box girder is composed of a wide flange instead of two main girder, the weight is small, but made more complex. Four by four pieces of plane truss girder structure combination into a closed space structure, on the surface level on the truss generally covered by bedplate, weight light, stiffness big, but compared with other structures, appearance size, made more complex, the fatigue strength is low, have less production.
The main beam is rigidly connected to the beam, and the ends of the beam are equipped with wheels to support the bridge. There is a track on the main beam for the crane to run. The structure of the main beam of the bridge is more typical of box structure, four truss structure and hollow truss structure. The box structure can be divided into two kinds: the two beams of the right box, the two girders of the offset box, and the monorail box. On track box double beam is widely used in a basic form, main girder by on either side of the upper and lower flange plate and the vertical web, rail car arrangement in the center of the line on the flange, its simple structure, easy fabrication, suitable for batch production, but gravity is bigger.
The composition of the portal crane: The crane operating mechanism generally USES only four active and driven wheels, and if the weight is large, the wheel is used to reduce the wheel pressure. When the wheel is more than four, it must be rearticulated and balanced frame so that the load of the crane is spread evenly over the wheels. The structure of the bridge is composed of the main beam and the beam, which is divided into single main beam bridge and double beam bridge. The single main beam bridge is composed of single main beam and end girder on both sides of the span, which consists of two main beam and end girder.
The portal crane is classified according to the structure of the frame, the form of the main girder and the hoisting form. It is commonly used in ports. In the form of door frame structure (a) all gate crane: the main beam has no suspension, the car is carried out in the main span. (b) semi-portal crane: the legs are low and low, depending on the requirements of the site. (c) double cantilever portal crane: the most common form of structure, the force of the structure and the efficient use of the site area are reasonable. The composition of the portal crane:
