Summary:
All you need to know about dock mounted crane
What is a dock mounted crane?
Performance characteristics of dock fixed cranes
Classification of dock fixed cranes
The main structure of the dock fixed crane
Future development direction of dock fixed cranes
In the article, you will learn about the structural composition, performance characteristics, classification, and development trends of dock fixed cranes.
What is a dock mounted crane?
Dock mounted crane refers to a crane that is fixed on a foundation or supported on a base and can only work in place. Fixed cranes can perform loading and unloading operations between shore and ship, with high work efficiency, good stability, flexible operation, and suitable for heavy loading and unloading operations. They are ideal loading and unloading equipment for port terminals. You can choose to configure hooks or grab buckets for loading and unloading operations, and can load and unload materials such as steel, bagged goods, wood, etc. with full working range. When using a multi limb specialized hook, it can lift multiple items of goods at once. When equipped with electromagnetic suction cups, scrap steel can be lifted.
A fixed crane is a type of handling machinery that lifts, lowers, and horizontally moves materials in an intermittent manner. The operation of a fixed crane usually has the property of repeated circulation. With the development of science, technology, and production, fixed cranes are constantly being improved and developed. Advanced electrical, optical, and computer technologies are being applied in lifting equipment, which tends to improve automation, work efficiency, and performance, making operations simpler, more labor-saving, and safer and more reliable.
Performance characteristics of dock fixed cranes
Flexible rotation: The rotating mechanism of a fixed crane adopts rotary bearings, which have the characteristics of flexible rotation and smooth driving.
Light weight and high strength: The steel structure of a fixed crane is made of section steel or steel pipes, which have the characteristics of light weight, high strength, and good wind resistance.
Easy to operate: The fixed crane adopts a simple, safe and reliable control system, which can achieve precise control and improve work efficiency.
Wide application range: Fixed cranes are suitable for various occasions, such as factories, docks, warehouses, etc., and can meet the lifting needs in different scenarios.
Classification of dock fixed cranes
Dock fixed cranes are divided into four categories: four link combination boom cranes, single arm rack and pinion variable amplitude cranes, full width loaded fixed cranes, and non full width loaded fixed cranes.
Four link combination boom crane:
The four link combination boom crane is mainly composed of a four link boom system composed of boom, elephant nose beam, and large pull rod combination, rack and pinion type variable amplitude mechanism, lever movable counterweight balance, column, turntable, cylindrical base, and other components. Use hooks or grab buckets for loading and unloading of general cargo or bulk cargo, and container lifting equipment can also be used for container loading and unloading operations. This model adopts AC variable frequency speed regulation, PLC control, and can be equipped with an intelligent “status monitoring control system”.
Advantages: Large working range, fast speed, safe and reliable operation, and advanced performance. The overall stability of the machine is good, and the lifting, rotating, and variable amplitude mechanisms can operate independently or in combination. Widely used for loading and unloading operations at major port terminals, it is an ideal model for comprehensive port multi cargo terminals.
Disadvantages: The boom is a combination boom with a complex structure, heavy weight, and high manufacturing cost.
Single arm rack and pinion variable amplitude crane:
The single arm rack and pinion variable amplitude crane is mainly composed of truss type single arm frame, rack and pinion variable amplitude mechanism, lever live counterweight balance, column, turntable, cylindrical base and other components. It uses hooks or grabs for loading and unloading of general cargo or bulk cargo, and can also use container lifting equipment for container loading and unloading operations. Widely used for loading and unloading operations at major port terminals, it is an ideal model for comprehensive port multi cargo terminals. Adopting AC frequency conversion speed regulation, PLC control, and the installation of an intelligent “state monitoring control system”.
Advantages: The boom is light, fast, and the overall stability of the machine is good. The lifting, rotating, and variable amplitude mechanisms can be operated separately or in combination.
Disadvantages: The working range of the boom should not be too long, and the horizontal displacement of the goods needs to be compensated with steel wire ropes, which makes the mechanism layout complex and increases the wear of the steel wire ropes.
Full width load fixed crane:
The full width load fixed crane mainly consists of truss type single arm frame, compensating pulley group, column, turntable, cylindrical base and other components. It uses hooks or grab buckets for loading and unloading of general cargo or bulk cargo, and can also use electromagnetic suction cups for operation. Widely used for loading and unloading operations at major port terminals, it is an ideal model for comprehensive port multi cargo terminals. This model adopts AC three-phase asynchronous speed regulation, conventional control, and can be equipped with an intelligent “state monitoring control system”.
The crane adopts a single boom pulley group compensation balance device to ensure that the goods move approximately horizontally during the amplitude change process, improving operational accuracy. The amplitude change mechanism can carry load for horizontal displacement, and the rotation mechanism can rotate at any angle. The entire machine can perform separate or joint operations for lifting, amplitude change, and rotation within the working range.
Advantages: The pulley compensation balance device ensures approximate horizontal displacement of the goods, with a light arm frame, low amplitude power, fast speed, good overall stability, high loading and unloading efficiency, convenient maintenance, and durability.
Disadvantage: The horizontal displacement of goods needs to be compensated with steel wire ropes, which makes the mechanism layout complex and increases the wear of steel wire ropes.
Non full width load fixed crane:
A non full width load fixed crane mainly consists of truss type single arm frame, pulley group, A-frame, turntable, cylindrical base and other components. It uses hooks or grab buckets for loading and unloading of general cargo or bulk cargo, and can also use electromagnetic suction cups for operation. This model adopts three-phase asynchronous speed regulation, conventional control, and can be equipped with an intelligent “state monitoring control system”.
The crane adopts a single boom steel wire rope variable amplitude form, which is flexible and easy to operate. It can operate frequently and continuously, with low maintenance rate and cost-effectiveness.
Advantages: Simple structure, convenient operation, and affordable.
Disadvantages: During the amplitude change process, the center of gravity of the goods rises or falls, resulting in high force on the amplitude change, increased motor power, and low loading and unloading efficiency.
The main structure of the dock fixed crane
The dock fixed crane consists of a lifting mechanism, a variable amplitude mechanism, a rotating mechanism, a hook, a double rope grab bucket, basic steel embedded parts, an electrical control system, a lubrication system, etc.
Hoist
The lifting mechanism consists of a variable frequency motor, a flexible coupling, a brake, a reducer, a toothed coupling, and a steel wire rope drum (including a steel wire rope pressing device). Two sets of lifting mechanisms are used to adapt to the working conditions of the hook and grab.
The electric control device of the lifting mechanism has good speed regulation performance, using frequency conversion speed regulation to meet the requirements of lifting speed under different lifting weights.
The lifting steel wire rope adopts a winding method, and the winding of the steel wire rope and the arrangement of the pulley group are conducive to the replacement of the steel wire rope and improving its service life. The drum is wound in a single layer and equipped with high-performance wire guide and rope pressing devices to prevent wire rope relaxation and jumping. In order to reduce the jumping of the steel wire rope, rubber pads are arranged along the arm frame. Equipped with dual hydraulic disc brakes, the brakes have good heat dissipation and stable friction coefficient. Ensure accurate and safe stopping at any height during long-term busy use.
The lifting mechanism is equipped with safety interlocking protection devices such as lifting weight detection, position limit of lifting height and lowering depth, speed limit, etc.
When the rated load is lifted to 95%, there is an audible and visual alarm. When the rated load reaches 110%, the protective device cuts off all controllers and only allows the goods to be lowered.
Luffing mechanism
The amplitude mechanism adopts AC frequency conversion speed regulation, the amplitude drive device adopts gear rack transmission, the arm frame self weight balance adopts lever movable counterweight type, and the counterweight inside the balance beam adopts detachable cast iron blocks. The drive of the variable amplitude mechanism consists of a variable frequency motor, a coupling, a double disc brake, a reducer, gears, and racks. There is a maximum and minimum amplitude limit device in the amplitude mechanism, and a maximum and minimum amplitude front deceleration limit protection device is installed to ensure the safety of equipment and personnel during operation. Set up a buffer with good performance for the amplitude mechanism. The layout of the variable amplitude mechanism considers easy installation, adjustment, and maintenance.
Wire rope type: The variable amplitude device consists of an independent winding device, namely: electric motor → coupling (including brake) → reducer → wire rope drum.
The amplitude modulation mechanism adopts a rotor series resistance speed regulation system, which has good speed regulation performance, ensuring uniform amplitude modulation speed, smooth operation, reliable operation, convenient maintenance, and low noise.
In order to reduce power loss and improve the operational performance of the crane, a wire rope compensation system is adopted in the mechanism to ensure approximate horizontal displacement of goods throughout the entire range of the amplitude.
The variable amplitude brake has sufficient braking torque and safety factor. Within the range of boom amplitude, the boom can be safely positioned and braked at any position in space. The braking device operates flexibly and is safe and reliable.
The performance of the variable amplitude mechanism is good, and it is reliable to use. The limit switch automatically stops at the maximum and minimum amplitude of the boom;
During maintenance, the boom can be placed at a height of 1 meter above the dock surface for the purpose of repairing the boom head.
Rotation mechanism
This institution consists of two parts: a rotating support device and two rotating drive devices. The rotating support device adopts a three row roller rotating support; The rotary drive device consists of an electric motor, a coupling, a foot variable frequency variable force brake, a vertical planetary reducer, an output shaft, an open small gear, and an outer gear ring (external meshing) of the rotary support. And equipped with electric centralized lubrication for forced lubrication of the rotating support.
This institution operates smoothly, safely, and reliably, and can rotate 360 ° in both directions. Install a rotating anchoring device and interlock it with the rotating mechanism. The unevenness, inclination, and stiffness of the upper and lower support surfaces of the rotary bearing meet the assembly accuracy requirements of the rotary bearing. Install a pin type rotating anchor device between the rotating part and the door pillar, and set two anti rotation anchor sockets on the cylinder.
lubrication system
The entire machine is equipped with an electric centralized lubrication device, which includes rotating and rotating pulleys and arm frames, providing reliable and effective lubrication conditions for bearings, gears, pulleys, and other moving parts. The intelligent centralized lubrication system has signals that can be sent by the crane control system to work or stop the centralized lubrication system, achieving remote control. At the same time, the total fault signal of the centralized lubrication system can be fed back to the crane control system for reporting, making it convenient for relevant personnel to query and handle.
Future development direction of dock fixed cranes
With the continuous progress and innovation of technology, the future direction of cranes will mainly include the following technological trends:
Intelligence: Cranes will become more intelligent and automated, and can be controlled and monitored through remote control, sensors, and automation technology to improve efficiency and safety;
Progressive innovation: Cranes continuously improve and innovate in terms of cost-effectiveness and performance, improving performance and reducing costs through the application of new materials and technologies;
Automation: The electrification of cranes will become the development direction. Electric cranes have higher energy efficiency and lower maintenance and repair costs;
Ecological and Environmental Protection: The design of cranes will pay more attention to environmental protection, reduce transportation pollution and energy consumption, and use sustainable materials.
Through the above text, we hope it will be helpful for you when choosing a dock mounted crane. For more information about cranes, please contact Nar.