How does topkit crane play a key role in the engineering field? ​

As an important member of the tower crane family, topkit crane is famous for its boom installed on the top of the tower body, forming a unique "Г"-shaped working space. This structural design gives it the ability to achieve long-distance, high-intensity and high-efficiency lifting and handling work within the space range. Its working principle is based on the basic operating logic of lifting machinery. The heavy objects are lifted by the lifting hook or other picking devices, and then the lifting mechanism, slewing mechanism and luffing mechanism are coordinated to achieve the vertical lifting and horizontal displacement of materials, so as to deliver various materials to the designated location at the construction site. ​
Top-mounted cranes have distinct characteristics and have significant advantages among many engineering equipment. Its amplitude utilization rate is extremely high. Due to the slender boom and the upright tower body close to the building, the layout of the boom at the top of the tower body enables it to fully utilize the working range. In contrast, the amplitude utilization rate of ordinary crawler and tire cranes is low, and this ratio will decrease as the building height increases. The tower height advantage of top-mounted cranes is obvious. It can provide a higher lifting height and meet the construction needs of buildings and structures with different numbers of floors and heights. Its lifting height mainly depends on the tower height. The higher the tower, the greater the lifting height. This feature makes it outstanding in the construction of super-high-rise buildings. The crane has reliable self-stability and balance performance, and does not require cable assistance. It has excellent lifting performance, can carry out vertical and horizontal transportation at the same time, and can achieve 360° full rotation movement, which is flexible and efficient to operate. Top-mounted cranes usually have multiple working speeds. The lifting mechanism includes normal operating speed, installation speed and empty hook lowering speed. These different speed modes improve construction production efficiency. It has a high degree of mechanization and standardization, can adapt to frequent site transfers, and the working process is stable, safe and reliable. ​
Top-mounted cranes are mainly composed of working mechanisms, metal structures and electrical parts. The working mechanism includes slewing, lifting, variable amplitude, walking and other mechanisms. Each mechanism works together to achieve different movement requirements. The slewing mechanism is composed of an electric motor and gear bearings, which provide power transmission, so that the goods can move in a circle with the tower as the center of rotation, expand the working range, and improve the efficiency of construction operations. The lifting mechanism focuses on achieving the rise and fall of the goods. It is composed of components such as motors, couplings, reducers, wire ropes and hooks to work together to ensure that heavy objects can be lifted and lowered safely and stably. The luffing mechanism can adjust the hook position according to the different positions of cargo loading and unloading, expand the scope of construction operations, and is composed of a winch, a guide pulley and a luffing trolley. The traveling mechanism includes two major parts: the supporting and operating device and the driving device. The supporting and operating device supports the overall weight of the crane, including components such as traveling wheels or trolleys; the driving device relies on the friction between the wheels and the top surface of the track to move the crane along the track, and includes components such as motors, brakes, reducers, gears, etc. ​
The metal structure is the supporting structure of the top-mounted crane, which is composed of the tower body, turntable, base, boom, balance arm, etc., and plays a structural support role for the entire machine. As one of the main structures, the tower body is built by the foundation section and the standard section. Its cross section is usually a square lattice structure. It is the foundation for the installation of other structures. It mainly bears the pressure caused by the weight of the rotating part, the torque caused by its inertia, and the bending moment caused by the weight of the cargo. The turntable is located between the rotating part and the fixed part. It consists of an upper and a lower frame. The upper frame is connected to the rotating tower body, and the lower frame is connected to the standard section of the tower body. The upper and lower frames are connected to the inner and outer rings of the slewing bearing with bolts respectively. The slewing platform of the upper slewing self-elevating tower crane mostly adopts an I-shaped cross-section ring structure welded by steel and steel plates. The slewing mechanism is installed on both sides of the turntable to ensure the stability and accuracy of the rotation. The base generally adopts a cross-shaped base frame, which is connected by bolts to a long whole beam and two half beams. The foundation section is located at the center of the cross beam, connected to the cross beam with bolts, and the upper end is connected to the standard section of the tower body. The support rod is a seamless steel pipe, and the two ends are connected to the four corners of the tower body and the base frame to form a stable spatial structure and increase the overall stability of the tower body. The boom adopts a variable cross-section lattice structure design, which mainly bears the pressure brought by the weight of the cargo and is a key component for realizing the horizontal displacement of materials. The balance arm adopts a flat frame structure and is connected to the counterweight to balance the bending moment caused by the weight of the boom, ensuring the balance and stability of the crane during operation. ​
The electrical part provides energy for the mechanical operation of the top-mounted crane, mainly including electrical equipment such as the drive device, control system and safety device. The drive device uses an AC motor to provide power for each mechanism to ensure the normal operation of the crane. The control system relies on the drive device and the brake device to accurately adjust the lifting, braking, speed regulation and safety of the mechanism to achieve control of the crane. The control system can not only complete the operation of the mechanism such as starting, braking, redirection and speed regulation, but also monitor the safety of the mechanism, play a role in safety protection, and display the working conditions in the form of current value, voltage value, speed, amplitude, lifting weight, torque, working position and wind speed, etc., to provide information for the operator. The safety device can avoid accidents caused by misoperation or failure of components, mainly including "two limits, four limits and three insurances". "Two limits" refer to the lifting torque limit device and the lifting weight limit device; "four limits" include the lifting height limit device, amplitude limit device, travel limit device and rotation limit device; "three insurances" refer to the pulley, drum and luffing trolley insurance device, wire rope anti-slip groove insurance device and hook insurance device. ​
In terms of application areas, top-mounted cranes have a wide range of uses. They play an important role in the construction industry, especially in the construction of high-rise buildings and large structures, and undertake the work of lifting and moving various materials. In the field of ports and logistics, they are often used in port loading and unloading operations and container terminals, handling cargo loading and unloading tasks with strong carrying capacity and high stability. In the wind power industry, they play a key role in the assembly and maintenance of wind power sites, lifting wind turbine components to the predetermined location and supporting subsequent maintenance and repair work. In bridge construction, they are used to transport bridge components and auxiliary equipment to promote bridge construction. In the petrochemical industry, they can be used to install and maintain large equipment and steel structures. In mining, chemical, energy and other industries, top-mounted cranes can also meet the lifting needs of different fields.