Steel factory equipment the weight
and center of gravity of each boom system luffing process is almost no
vertical displacement. One
way is by adding events counterweight to balance the lifting boom
system changes the center of gravity of the pitch synthesis when this
method is more convenient arrangement, work is also more reliable and
widely used. The semi gantry cranes second
method is to rely on institutional characteristics of the boom system to
ensure that the movement trajectory when the center of gravity close to
the level luffing synthesis, No activity counterweight.
Crane supplier along the trajectory of
the heavy lifting to move closer to the horizon in the luffing process,
compensation methods and compositions can be used boom law. Compensation
Act by the special storage system automatically retractable rope
hoisting rope luffing appropriate process to compensate boom lift
spreader vertical displacement caused. Arm method is to rely on institutional characteristics guarantee Arm arm ends move closer level luffing process. Both methods are widely used.
Use can be divided into three categories:①
cargo handling portal crane : mainly used
in ports and open stockyard, handling with grab or hook. From the weight of not more than 25 tons, not with the magnitude of the change. Higher operating speeds, it is often an important indicator of productivity.② portal crane manufacturer， shipbuilding
gantry crane: mainly used for berth, floating docks and outfitting
scene, performed splicing hull, outfitting equipment and other lifting work, with a hook as a spreader. Maximum lifting capacity of 300 tons, from the weight of large amplitude is reduced accordingly. How stall lifting speed, light weight lifting when lifting speed can be increased. Some agencies also work with micro-devices to meet the installation requirements. Gantry height greater, can be adapted to the requirements of large
lifting height and substantial job, but the operating speed is low, job
productivity is not high.
③
construction and installation with portal cranes: mainly used in
irrigation dam hydropower station, hoisting equipment and prefabricated
parts, usually with hooks. From the weight and the operating speed is generally between two cranes before. It
has good transport machine disassembly, spreader decentralization
depth, can better adapt to temporary work and work on the bridge and
other features.
Semi gantry cranes is
between an overhead crane and gantry crane between semi gantry cranes
have only one leg crane
bridge crane as the other end as the plant crane beam frame, frame
orbit on a plant commonly known as day orbit, the orbit on the ground,
said ground rail. Semi-gantry crane hoisting mechanism, trolley traveling mechanism and bridge construction, and bridge crane basically the same. Since
the span, crane operating agencies they use are driven way to prevent
the crane operation produce skew increases resistance, even accidents,
in order to prevent falling or tipping lines in strong winds, wind
measurements and is equipped with interlock operating agencies Crane rail clamp.
Semi-gantry crane electric hoist normally, so the rated capacity is usually 16 tons or less.Portal crane Use of box type and truss structure, the most widely used. You can carry a variety of bulk materials into items and, from the weight of 100 tons, a span of 4 to 39 meters. Grab common with the work of a higher level gantry crane. Common gantry crane mainly refers hook, grab, electromagnetic, hoist gantry crane, but also includes semi-gantry cranes.
