Crane (crane) operation normally just four driving and driven wheels

Crane (crane) operation normally just four driving and driven wheels, if the weight is very big, bridge gantry crane used to increase the wheel round ways to reduce pressure. When the wheels for more than four, must adopt balanced articulated frame device, make the crane load evenly distributed on each wheel. Bridge of the metal structure is composed of main girder and end beam, divided into the single main girder bridge and double beam bridge two kinds. Single main girder bridge by single girder and in the end on both sides of the span of beam, double girder frame is overhead gantry crane of two main girder and end beam. Main girder and end beam, rigid connection on both ends of the beam is equipped with wheels, to support bridge run on overhead. Main girder welding on the track, for lifting the car running. The structure of the bridge girder type is more than the typical box structure, four truss structure and vierendeel truss structure. Box structure and can be divided into the right box double beam, partial rail box double beam, partial rail box girder to wait for a few kinds. 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. 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. 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. General bridge crane mainly driven by electricity, generally is in the driver indoor manipulation, also has a remote control. Lifting weight of up to five hundred tons, the span of 60 meters. Simple beam bridge crane, also known as crane beam, its structure is similar to ordinary bridge crane, lifting weight, span and working speed are smaller. Bridge girder is composed of steel and plate steel beams or other simple beam, with chain or electric hoist with simple and easy as lifting trolley car, the car at the bottom flange of the h beam. Can bridge along the orbit, on a high shelf can also be along the suspension in elevated the orbit, below this kind of crane is called suspension girder crane. Special metallurgy bridge crane in the process of iron and steel production may take part in the process of the specific operation, the basic structure similar to ordinary bridge crane, but also on lifting the car is equipped with special working mechanism or device. The working characteristics of this kind of crane is used frequently, conditions, job level is higher.