6t flat top tower crane china,gantry container crane china,used tower crane
The structure characteristics of hoist boom
Pitch luffing jib tower cranes relies on hoist boom lift unrealized amplitude, its advantage is: can give full play to the effective height of hoist boom of, simple structure, is limited in the biggest drawback is that the minimum amplitude of 30% or so, can't completely close to the tower, when amplitude load with crane boom lift, can't load range.
Car luffing jib of tower crane is to rely on horizontal jib track installed on the car walks the realization of amplitude, its advantage is: wide range, load the car drove up to the tower, can load amplitude, the disadvantage is that: the lift arm force is complex, the structure of the demand is high, and the boom and the car must be in the upper buildings, towers installation height is 15-20 meters higher than building roof.
The tower structure rotary way
Rotary tower crane slewing bearing, balance weight under the major institutions, etc are all installed in the bottom, its advantage is: the less moment tower, low center of gravity, good stability, easy installation and maintenance, the disadvantage is that higher requirements for slewing bearing, installation height is limited.
Rotary tower crane slewing bearing, balance weight, major institutions are set at the top, its advantage is because the towers are not turning, can simplify the structure of the tower bottom and top section is convenient. The disadvantage is that: when building over the tower height, because of the influence of the balance arm, limit tower crane slewing, at the same time high center of gravity, wind pressure increases, the weight increase, so the total weight increase.