Home > Products > Crane Parts

Crane Girder

Crane Girder

Crane girder includes overhead crane girder and gantry crane girder. Overhead crane girder has overhead crane single girder and overhead crane double girder. While gantry crane girder has gantry crane single girder, gantry crane double girder and gantry crane truss girder.LXbHenan Dongqi Machinery Co., Ltd

 LXbHenan Dongqi Machinery Co., Ltd

Overhead Crane Girder Structure Form

Crane girder mainly use box-type structure and truss structure, while the box-type structure crane girder is the most widely used.LXbHenan Dongqi Machinery Co., Ltd

crane-girder-structure.jpgLXbHenan Dongqi Machinery Co., Ltd

Crane Girder StructureLXbHenan Dongqi Machinery Co., Ltd

Overhead crane usually used box-type structure girder. The box crane girder consists of upper and lower cover plates and two vertical cover plates, which are closed box-shaped section structures. In order to reduce the weight and make of equal strength beam, the lower edge of the web and the lower cover should be made of parabolic shape. However, to facilitate the production, usually the middle of the web is rectangular, and both ends are trapezoid, so that the lower cover can be tilted at both ends.LXbHenan Dongqi Machinery Co., Ltd

crane-girder-single-girder.jpgLXbHenan Dongqi Machinery Co., Ltd

Overhead Crane Girder LXbHenan Dongqi Machinery Co., Ltd

The box-type crane girder can adopt the whole steel plate welding, which is easy to use active welding and semi-active welding. It has the advantages of simple planning, good fabrication technology and suitable for batch production. It is the most widely used construction method.LXbHenan Dongqi Machinery Co., Ltd

Why should the main crane beam have the camber?

crane-girder-camber.jpgLXbHenan Dongqi Machinery Co., Ltd

The crane girder has the following effects on the camber:LXbHenan Dongqi Machinery Co., Ltd

  • It can reduce the downward deformation of the main girder under load, so that there is a minimum inclination of the trolley track, thereby reducing the resistance of the trolley running to prevent the trolley from climbing or rolling phenomenon and improve the trolley's performance
  • For the trolley operating mechanism is a centrally driven crane, the camber can improve the running performance of the crane because the camber can counteract the downward deformation of the crane girder
  • Camber can enhance the carrying capacity of the crane main beam, the main beam of the stress conditions have been improved.

The Down Deflection of Crane Girder

The down-warping of the crane main beam is the permanent deformation of the bending of the crane main girder, from the original height.LXbHenan Dongqi Machinery Co., Ltd

crane-girder-down-deflection.jpgLXbHenan Dongqi Machinery Co., Ltd

The main reason for the serious down deflection of the crane girder is:LXbHenan Dongqi Machinery Co., Ltd

  • Overload operation
  • Corrosion
  • High temperature effects
  • Improper repair
  • There is no regular inspection of metal structures and technical appraisal, the deformation is not repaired in time

Gantry Crane Girder Types and Advantages

Usually the main girder structure of gantry crane has truss beam, box girder and honeycomb beam.LXbHenan Dongqi Machinery Co., Ltd

Gantry crane truss beams are usually made of angle steel or I-beam through welding process. Although it has the advantages of low cost, light weight and good wind resistance, the truss has the disadvantages of large surrounding degree and small rigidity due to many welding points and defects of the truss itself, low security and stability, the need for frequent testing of solder joints and other shortcomings.LXbHenan Dongqi Machinery Co., Ltd

gantry-crane-truss-type-girder.jpgLXbHenan Dongqi Machinery Co., Ltd

Gantry Crane Truss GirderLXbHenan Dongqi Machinery Co., Ltd

Gantry crane box girder is mainly made of steel plate or I-beam welded steel processing box structure, which has the advantages of high safety and reliability, stiffness and other advantages, but the gantry structure of the gantry crane high cost, heavy, the deficiency of relatively poor wind resistance.LXbHenan Dongqi Machinery Co., Ltd

gantry-crane-box-type-girder.jpgLXbHenan Dongqi Machinery Co., Ltd

Gantry Crane Box Type GirderLXbHenan Dongqi Machinery Co., Ltd

The main face of the honeycomb beam is isosceles triangle, on both sides of the waist have honeycomb holes, upper and lower chords. Honeycomb beams have the advantages of truss girders and box girders, but the honeycomb beams are welded with steel plates, so the dead weight and the cost are higher than the truss beams.LXbHenan Dongqi Machinery Co., Ltd

gantry-crane-honeycomb-beam.jpgLXbHenan Dongqi Machinery Co., Ltd

Gantry Crane  Honeycomb BeamLXbHenan Dongqi Machinery Co., Ltd

Differences between Box-type Crane Girder and Truss Crane Girder

  • Under the same conditions, the truss structure crane girder is stronger than the box-type structure crane beam, but the truss structure crane girder is easy to show stress concentration and even crack
  • Box-type structure crane girder relatively heavier than truss structure
  • Box-type structure crane girder is easy to manufacture
  • Box-type structure crane girder can use angular bearing box, connected with the end of the beam stress concentration, easy to crack

Crane girder is the foundation of the crane. Dongqi Group can provide you crane girder design service. Also we can supply you overhead crane, gantry crane and crane spare parts.LXbHenan Dongqi Machinery Co., Ltd