Structure of lifting machinery

Working institutions include: hoisting mechanism, operating mechanism, luffing mechanism and rotating mechanism, which are called the four major institutions of cranes.

(1) The hoisting mechanism is a mechanism for realizing the vertical lifting of materials. It is an indispensable part of any crane and is therefore the most important and basic mechanism of the crane.

(2) The operating mechanism is a mechanism for moving materials by crane or lifting trolley. It has the functions of trackless operation and rail operation. It is divided into two types according to its driving mode: self-propelled and traction.

(3) The luffing mechanism is a unique working mechanism of the boom crane. The luffing mechanism changes the working range by changing the length and elevation of the boom.

(4) The rotating mechanism is to make the boom rotate around the vertical axis of the crane to transport the material in the annular space. The crane achieves the purpose of carrying materials by a single movement of a mechanism or a combination of multiple mechanisms.

1, The drive device

The drive unit is used to drive the power unit of the working mechanism. Common driving devices include electric drive, internal combustion engine drive and manual drive. Electrical energy is a clean, economical energy source. Electric drive is the main driving type of modern cranes. Almost all rail cranes, elevators, elevators, etc. that operate within a limited range are electrically driven. For mobile cranes that can be moved over long distances (such as tire cranes and crawler cranes), internal combustion engine drives are often used. The human drive is suitable for some light and small lifting equipment, and is also used as a temporary power for auxiliary, backup drive and accident (or accident) of certain equipment.

2, Take the device

The picking device is a device for lifting materials by lifting, grasping, sucking, clamping, supporting or other means to connect the materials with the crane. Different types of material picking devices are used depending on the type, shape and volume of the materials to be suspended. For example, the articles are commonly used as hooks and rings; bulk materials (such as grain, ore, etc.) are commonly used for grabs and hoppers; liquid materials are used for tanks and tanks. There are also special spreaders for special materials, such as lifting overhead monorail system beams for lifting long materials, lifting electromagnetic suction cups for lifting magnetic materials, rotating hooks for metallurgical and other departments, and screw unloading. And the pick-up device such as the bucket wheel unloading, and the special spreader for the container. A suitable pick-up device can reduce the labor intensity of the operator and greatly improve work efficiency. Preventing the falling objects from falling, ensuring the safety of the workers and the damage of the hanging objects are the basic requirements for the safety of the picking device.

3, Metal structure

The metal structure is made of a metal material rolled steel (such as angle steel, channel steel, I-beam, steel pipe, etc.) and steel plate as basic components. It is connected by a certain composition rule by welding, riveting, bolting, etc., and bears the crane. Self-weight and load steel structure. The weight of the metal structure accounts for about 40% to 70% of the weight of the whole machine, and the heavy crane can reach 90%; the cost is about 30% of the cost of the whole machine. The metal structure can be divided into solid type (made of steel plate, also called box structure) and lattice type (usually made of steel, common with root frame and lattice column) according to its structure, which constitutes crane metal. The basic force-bearing component of the structure. These basic force-receiving members include a column (axial force-receiving member), a beam (bending member), and a boom (bending member), and different combinations of the various members form a crane having different functions. Complicated forces, self-importance, consumables and overall mobility are the working characteristics of crane metal structures.

4, the operating system

Through the electric and hydraulic system control, the movement of each mechanism of the crane and the whole machine are controlled, and various lifting operations are performed. The control operating system includes various manipulators, displays and related components and lines, and is an interface for human-machine dialogue. The requirements for safe ergonomics are concentrated here. The state of the system is directly related to the quality, efficiency and safety of the lifting operations.

The significant difference between cranes and other general machines is the combination of large, movable metal structures and multiple mechanisms. Intermittent cycle operation, unevenness of lifting load, inconsistency of movement cycle of various mechanisms, unequal time of mechanism load, and coordination work of multi-person participation increase the complexity and safety hazard of cranes. More, the scope of danger is large. The safety of cranes is particularly important because of the many accidents and the serious consequences of accidents.