(1) Girder cranes: Girder cranes mainly include single-girder bridge cranes and double-girder bridge cranes
The main beams of the single-girder bridge crane bridge frame mostly adopt I-beams or a combined section of steel profiles and steel plates. Hoisting trolleys are often hand chain hoists, electric hoists or assembled with hoists as components of the lifting mechanism.
It is classified into two types according to the bridge frame method: supported type and suspended type. The former bridge frame runs along the crane track on the vehicle girder. The latter's bridge frame runs along the crane track suspended under the factory roof truss. Single-girder bridge cranes are divided into manual and electric types. The working speed of each mechanism of the manual single-girder bridge crane is relatively low, and its lifting capacity is also small. However, its own weight is small, which is convenient for organizing production and has a low cost. It is suitable for occasions where the handling volume is not large after there is no power supply and the requirements for speed and productivity are not high. The manual single-girder bridge crane uses a manual monorail trolley as the running trolley and a hand chain hoist as the lifting mechanism. The bridge frame is composed of the main girder and the end girder. The main beam is generally made of a single I-beam, while the end beams are welded with section steel or steel plates formed by pressing and bending.
The working speed and productivity of electric single-girder bridge cranes are higher than those of manual ones, and their lifting capacity is also greater. The electric single-girder bridge crane is composed of the bridge frame, the traveling mechanism of the large vehicle, the electric hoist and the electrical equipment, etc.
