Construction Hoisting Machinery (Tower)

Description
As kind of hoisting equipment, tower crane is mainly used to vertically and horizontally deliver materials in housing construction and to install building component. Such construction hoisting machinery consists of metal structure, operation mechanism and electric system. Metal structure includes tower body, swing arm and base, etc. Operation mechanism is composed by hoisting, jib lubbing, swing and traveling mechanism. Electric system is composed of electromotor, controller, distribution cabinet, interconnecting link, signal and illuminating apparatus.

Components
According to different functions, tower crane components is composed of base, tower, lift-up, swing mechanism, hoisting mechanism, balance arm, cargo boom, lifting trolley, tower top, operators cab and jib lubbing mechanism, etc.
If tower crane is installed on the ground, base is needed. Tower (body) is the elevated part. Lift-up part can raise tower crane. The swing mechanism keeps the upper part rotating horizontally. Hoisting mechanism is utilized to lift heavy materials. Balance arm can keep the moment balanced. Cargo boom rack refers to stressed part of cargo lifting. Lifting trolley is used to set up pulley block and lifting hooks. Tower top keeps the cantilever crane evenly stressed. Operators cab is an operating place. Jib lubbing mechanism keeps the trolley move in an orbit.

Classification
1. Upward rotary type and downward rotary type. The bearing capacity of the former is larger than that of the latter.
2. According to luffing method, construction hoisting machinery can be divided into compression bar pattern and horizontal trolley type.
3. According to lifting load, construction hoisting machines can be sub classified into light, middle-sized and heavy-duty type.
4. According to the motion, it can be divided into walking tower crane and stationary construction hoisting machinery. The stationary one is usually adopted in house building construction. And the tower body is fixed and is installed upon whole piece of concrete foundation or is equipped on X-shape concrete foundation. Walking tower crane can be further classified into crawler type, truck type, rubber-tyred and rail-mounted construction hoisting machinery.
5. According to amplitude method, it can be subdivided into horizontal arm trolley and swing arm amplitude tower crane.
6. According to installing form, it can be classified into self-elevating type, overall quick disassembling type and split mounting type.
Downward rotary, overall quick disassembling, rail-mounted type tower cranes and self-elevating construction hoisting machinery are most widely used.

Features
1. Tower crane features convenient operation.
2. Vertical and horizontal transportation can be carried out synchronously. What’s more, such construction hoisting machinery makes it possible to successively finish lifting, delivering, loading and unloading.
3. Tower crane is characterized by simple structure and good reliability.
4. Such construction hoisting machinery has enough hoisting height and larger working space.
5. Bristol tower crane has the advantage of novel mechanism, reliable operation, elegant appearance, high working speed, good speed regulating performance and high efficiency.
6. The operator cab is allocated with complete communication device. Besides, it is comfortable and vision cleared.

Advantages
The lifting weight will change with amplitude. Load moment (lifting weight × amplitude) is main technical parameter for tower cranes. With swing mechanism and swing bearing, construction hoisting machinery has high lifting height and large intertia mass. Thus, it features good speed control performance. Besides resistance velocity modulation, eddy current brake, speed control, silicon control and electrical-mechanical speed regulation are employed. Tower crane has safety device, such as lifting weight, amplitude, height and load moment limit equipments, etc. Besides, construction hoisting machinery is allocated with lead limit switch, signal light, wind meter, and wind proof rail clamp, etc.

Maintenance
Maintain and lubricate tower crane regularly so as to guarantee safety and prolong its working life.
1. Keep the whole machine clean and clean it timely.
2. Check reduction gear oil and refill timely.
3. Check steel wire ropes to see whether they are loose, broken or worn out. Replace steel wire ropes timely if the above problems appear.
4. Check the efficiency and intervals of brakes in order to guarantee reliable sensitivity.
5. Check the reliability and sensitivity of all safety equipments.
6. Check every bolt connection, especially standard section connecting bolts and fasten them regularly.
7. Check and tight the pressing plate and clamp of steel wire rope timely.
The scrapping of steel wire rope, coiling block, pulley wheel and lifting hook, etc. should strictly conform to GB5144 and GB5972 stipulations.
8. Check rod pieces, web members and weld joint to see whether they are cracked. Pay more attention to paint peeling parts. If the paint is peeling into diagonal stripes by 45°, it would be dangerous. And operators should find out reasons immediately and dispose in time.
9. All the connecting bolts and nuts and pin rolls with connecting diameter above Φ 20 cannot be substituted in any case. When installed, every bolt should be screwed with two nuts.
10. Standard bolt performance level is 10.9. Nut performance level is 10 (double nuts anti-loose). Bolts and nuts with no performance grade marks are not allowed to be used.
11. Derust and paint the whole machine and metacor after every project.
12. Check whether automatic ratio change device and off-rope proof device are safe and reliable.
13. Observe whether the electrical contact terminals are oxidized or burnt out. If contact miss occurs, repair or replace them timely.
14. All the limit switches and buttons should not be out of order. If the parts and components are rusty or damaged, replace them in time.
15. The insulation of all the electric switch and switch boards must be favorable with insulation resistance above 0.5 MΩ.
16. Check whether fastening bolts are loose and if electric cables and other wires are broken.

Attention
1. Choose tower cranes with production certificate authorized by the government.
2. Shop around and choose the best construction hoisting machinery.
3. Inspect the incoming construction lifting machine carefully.

Common Faults of Tower Crane
1. Lifting hook glides and amplitude trolley slides after braking.
2. During the operating process, the brake is hot and gives out smoke.
3. The temperature of gear reducer is too high.
4. The bearing temperature of reducer is excessively high.
5. The reducer leaks oil.
6. Slow lifting speed.
7. Powerless lifting or unable hoisting.
8. Noise and vibration occur when lifting pressure increases.
9. Hoisting mechanism doesn’t work.
10. Crawl and vibration appear when lifting.
11. Lifting shoring drops when loaded.
12. The general start button is out of order.
13. The circuit trips when lifting movement goes on.
14. Lifting mechanism cannot start.
15. Hoisting mechanism generates much noise and vibration.
16. The bearing of hoisting mechanism is over heated.
17. Hoisting mechanism is electrified.
18. The brake of hoisting mechanism is out of order.
19. The temperature of hauling mechanism is too high or gives out smoke.
20. Swing mechanism cannot start.

Payment: T/T or L/C at sight
Mode of Transportation: By Motor in China, By Sea Abroad

Bristol Compressors (Shanghai) Co., Ltd. is a professional manufacturer of tower cranes in China. We provide high quality construction hoisting machinery. We have strict quality checking system so as to guarantee the quality of our products. Bristol (Shanghai) Co., Ltd. never compromises to sacrifice quality to get low price. For detailed information about our tower cranes, please visit our website and contact us directly.