What are the characteristics of a tower crane?
Four, according to the different installation methods of cranes, can be divided into folding transport, self erection of the rapid erection of tower cranes and the need to use the auxiliary machine assembly and disassembly of tower cranes.Can set up their own fast loading crane are small and medium slewing tower crane, mainly used for short duration, low buildings move frequently, the main advantage is to improve work efficiency, save installation cost, save time and labor and material, disadvantage is the complicated structure, large amount of maintenance.A tower crane that needs to be disassembled and assembled by an auxiliary machine is mainly used in middle and high rise buildings, with large working range and large lifting capacity. It is the main type of construction site at present.Five, according to whether the spire structure, can be divided into flat head tower crane and tower tower crane.Tower crane is a new type of tower crane is developed in recent years, its characteristic is the tower cap and the rod part before and after the cancellation in the structure of the original tower crane on the enhanced structural strength of the arm and balance arm, arm and balance arm is directly connected, the utility model has the advantages of:1 、 the whole machine is small in size, easy to install and safe, reduce transportation and storage costs;2, the boom of tolerance and good performance, uniform stress, small damage on the structure and connection part;3, component design can be standardized, modular and interchangeable, reduce equipment idle, improve investment efficiency.It is in the same type of tower crane tower crane head Zhongping slightly higher prices.
Two, according to the structure characteristics of the boom can be divided into the pitching amplitude boom (boom) and trolley jib tower crane (arms).Luffing jib tower crane luffing jib by lifting does not achieve the amplitude, the utility model can give full play to the effective height of the boom, simple mechanism.Trolley jib tower crane is installed on the level of the boom on the track trolley achieve amplitude, the utility model has the advantages of large amplitude range, trolley can near the tower, can load amplitude, the shortcoming is: the boom stress on the structure of complex, high requirements, and the boom and the car must be in the building the upper part of the spire, the installation height should be higher than the roof of buildings 15-20 meters.Three, according to the turret structure, the rotation mode can be divided into lower slewing (turret rotation) and upper slewing (turret not slewing) tower crane.Under the rotary tower crane slewing bearing, balance weight mechanism are arranged on the lower end of the main tower, its advantages are: less bending, low gravity, good stability, convenient installation and maintenance, the disadvantage is the higher requirement to the slewing bearing, installation height is limited.The slewing tower crane is characterized in that the slewing bearing is balanced and the main mechanisms are arranged at the upper end, and the advantage of the utility model is that the lower part of the tower body can be simplified, and the lifting and the adding of the joint can be simplified because the tower body is not turned. The disadvantage is: when the building exceeds the tower height, due to the influence of the balance arm, limit the slewing of the crane, at the same time, the center of gravity is higher, the air pressure increases, the weight increases, so that the total weight of the whole machine increases.
Classification and characteristics of tower cranesAccording to whether or not there is a walking mechanism, it can be divided into movable tower crane and fixed crane.Mobile tower cranes can be divided into four types: track type, tyre type, automobile type and caterpillar type according to the difference of walking device.The track type tower crane tower body is fixed on the walking underframe, and can be operated on the specially designed track. The utility model has good stability, can walk with load, and has high work efficiency, so the utility model is widely used in construction and installation engineering.The wheel type, the automobile type and the crawler type tower crane have no track device, and they are easy to move, but can not walk with load and have poor stability.The fixed tower crane can be divided into two types: the attached self lifting type and the internal climbing type according to the different installed positions:The attached tower crane can rise as the building rises. It can be applied to the high-rise building. The structure of the crane can only bear the horizontal load from the crane, but it is easy to use, but it occupies more steel structure;The internal climbing crane in the interior of the building (elevator, staircase), up through a set of system and improve the lifting bracket, is complicated, but occupy steel less, do not need to be installed, all the weight and load by building bear.
