Tower cranes are simply referred to as tower cranes, also known as tower cranes, and originated in Western Europe. It is mainly used for vertical and horizontal transportation of materials and installation of building components in house construction.
From the perspective of tower crane technology development, although new products emerge in an endless stream, new products have improved in production efficiency, easy operation, easy maintenance and reliable operation, but the tower crane technology has not changed fundamentally. The research of tower crane is moving towards the combined development. That is, taking the tower body structure as the core, according to the structural and functional characteristics, the tower body is decomposed into several parts, and according to the requirements of serialization and generalization, each part is divided into several modules according to the principle of the modular system. According to the parameter requirements, select appropriate modules to form tower cranes with different technical performance characteristics to meet the specific needs of construction.
Tower cranes are divided into two categories: upper slewing tower cranes and lower slewing tower cranes. The bearing capacity of the former is higher than that of the latter. What we have seen in many construction sites is the tower crane with the upper rotary type, the upper lifting and the joint height. According to whether it can move, it is divided into walking type and fixed type. The tower body of the fixed tower crane is fixed and does not turn, and is installed on the whole concrete foundation, or on the X-shaped concrete foundation in the form of a bar. The fixed type is generally adopted in the construction of houses.
In order to ensure safety, the tower crane has good safety devices, such as limit devices such as lifting weight limiter, amplitude limiter, height limiter and load torque limiter, as well as travel limit switch, tower top signal lamp, Anemometer, windproof rail clamp, ladder guard ring, walkway guardrail, etc. Through the slewing mechanism and slewing bearing, the tower crane has a large lifting height and a large inertial mass for slewing and walking, so it needs to have good speed regulation performance. In particular, the lifting mechanism requires light and fast load, heavy load and slow speed. Bit fretting. In addition to the use of resistance speed regulation, eddy current brake, frequency modulation, pole change, thyristor and electromechanical combination are often used to adjust the speed.
