tower crane

11  Security & Protection Mechanism
Besides security mechanism usually used in domestic tower crane adopted, tower crane adopted lots of advanced mechanism self-developed, to keep the security of the tower crane and convenient operation, such as unique double tighten mechanism on luffing steel cable, anti-break mechanism on sliding vehicle, anti-drop mechanism on standard section, speedy link between rotary body, hoisting boom and balance boom.

10  In general, the electric fault occupies 70% of all tower crane faults. However, tower cranes have fewer faults than others tower cranes, because of advantage of electric system design, fitness parameter of special motor, small impact, world-renowned electric components, and correct use of customers.

9                    The main electric elements are used world-renowned products, it is the key of high reliability of  tower crane, such as contactor and circuit-breaker of France Schneider, PLC controller of Japan Mistubishi Companies, and frequency converter of Japan Yaskawa Electric Corporation. Those components have over load capacity and stable performance.

Adopt PLC in electrical control system to improve reliability and safety. Using PLC (programmable logic controller) as the main control unit, it is very useful to reduce the quantity of logic control components, decrease the failure rate of the control system, and improve the reliability. The system controls the three mechanisms (Hoisting mechanism, Slewing mechanism and Trolleying mechanism) together, collects all the safety-limit signals, and deals with those signals in complicated logic, it is very efficient to optimize the mechanisms motion and avoid false operation. The system can self-diagnose electric faults and give corresponding alarms with different sounds and lights.

8  Electrical control system

7The motor connects with the planetary reducer, and then connects with the wheel. The mechanism has high reliability and following advantages: the structure is simple, the weight is light, the volume is small, and the figure is good-looking.

A planetary reducer and the technology of frequency altering and stepless speed regulated are adopted in the traveling mechanism. The speed of the traveling mechanism changes in the range of 025m/min smoothly without impact.

6Traveling mechanism

5The trolleying mechanism which affects the load filling its shoes, is important mechanism. Using the two speed electric motor, the speed of the trolley is 42/21m/min, the running impact is small and improve the operating stability and working efficiency in TC5015A.

4The unique technology of frequency altering and stepless speed regulated is adopted in the routine slewing mechanism first in the world. Using the slewing eddy controller, which owns the intellectual property, and technology of frequency altering and stepless speed regulated, the slewing mechanism starts and stops smoothly, fills its shoes fast and correctly.

As opposed to other mechanisms, the inertial impact of the slewing mechanism has the most effect to the crane. The more the jib is long, the more effect is outstanding. It cant solve the knotty problem with the traditional slewing mechanism, which brings about big torsional pendulum impact on the crane. After the motor being powered off, the jib runs for a long time before stopping, lead to difficultly fill its shoes and damage the slewing reducer.

3  Slewing mechanism

According to the demands of users, the frequency altering and stepless speed regulated motor, or the two-speed coiling rotor and eddy-brake speed regulated motor is adopted in hoisting mechanism, it is very useful to improve the running stability, raise the accuracy of filling its shoes, have no impact to electric network, and simplify the operation.

2 , Using the special motor and single-velocity-ratio spur gear reducer, the mechanism has simple structure, high reliability and easy maintenance.

The routine hoisting mechanism lifting 6 tons is adopted the three-speed pole-changing motor. With small inertial impact, and simple and reliable control system, it is very outstanding to prolong the lifetime of the contactor, and assure that the mechanism has high reliability. Adopting the technology of big strong drum, it is very useful to solve the knotty problem of abnormal orders when the wire rope is arranged on the drum.

The hoisting mechanism of the tower crane is designed to lift 6 tons.

1  Hoisting mechanism

  Introduction of Tower Crane TC5015A: