The process of changing the span of bridge crane from large to small

What is the span of a bridge crane?

Bridge crane span: The distance between the two track centerlines of the bridge crane running track is called the span of the crane. Denoted as: L. The unit is generally: M

There is also a kind of span: the distance between the center lines of the running track of the overhead crane trolley is called the trolley gauge. Sometimes called gauge. Denoted as: I.

How to determine the span of a small single-girder bridge crane

The stability of a double-beam crane is much higher than that of a single-beam crane. Generally, the span of a single-beam crane should not be too large. Under normal circumstances, it is recommended to be less than 22.5 meters. If the span is too large, the height of the box girder of the main girder increases quickly, and the most important thing is that the horizontal rigidity of the main girder is difficult to meet. Single girder cranes often shake in the horizontal direction when they are opened, which has great harm to the structure of the crane. There are safety hazards in long-term use. In addition, due to the large span and the camber in accordance with national standards, the electric hoist needs to climb a long slope during the walking process, and it is also easy to cause slippage and wear of the track. If the traveling mechanism of the crane adopts the frequency conversion speed regulation system, the impact force and anti-skidding ability of the traveling mechanism will be improved, and the working level and span of the single-beam crane can be improved accordingly.

How to change the span of bridge crane from large to small

• (1) Put the main girder of the bridge crane on the platform or the mat according to the working position, that is, the lower cover is placed at the bottom, and the restructured span line is drawn on the upper cover of the main girder on the side without the control room , And marked with a punching eye.
• (2) Use gas cutting to cut off the excess trolley track.
• (3) According to the joint form and size of the original main beam and end beam, draw lines at the position where the restructuring is decided, and pay attention to retaining enough upper and lower cover plate length to prepare for the reassembly of the main beam and end beam.
• (4) Cut the main beam according to the gas cutting line, and ensure that the upper and lower cover plates are not damaged during gas cutting.
• (5) Remove the gas cutting slag, paint and other dirt, and use a wind shovel and a grinding wheel to smooth the residues at the upper and lower cover plates.
• (6) Assemble the lower cover. If the lower cover is thick, flame heating and hammering and simmering are allowed to form a slope. The socket at the end of the main beam should be 2mm larger than the height of the end beam to facilitate the assembly of the end beam.
• (7) Weld the welding seam between the lower cover plate and the slope part of the web.
• (8) The repair of the end beam of the bridge crane and the assembly process requirements of the main beam and end beam, walking platform, etc. are the same as the aforementioned process of changing the span from small to large.

What is the impact of the span of the bridge crane, such as the same rated lifting capacity, different spans, what is the difference in the end beam force?

The span of the bridge crane will affect the design of the main box girder mechanism of the crane. Under the same rated lifting capacity, the larger the span of the crane, the larger the design of the main box girder mechanism. The larger the end beam is also designed, the bearing capacity is proportional to the span.

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