Definition and working characteristics of cranes.
Crane: A machine that uses a hook or other grabbing device to suspend heavy objects and perform cyclic operations such as lifting and transportation in space. GB/T6974.1-2008 Crane Terminology Part 1: General Terminology.
"Regulations on Safety Supervision of Special Equipment" Crane: refers to electromechanical equipment used for vertical lifting or vertical lifting and horizontal movement of heavy objects. Its scope is defined as elevators with a rated lifting capacity greater than or equal to
0.5t; cranes with a rated lifting capacity greater than or equal to 1t and a lifting height greater than or equal to 2m, electric hoists in fixed support forms, etc.
Working characteristics: Intermittent motion means that in one or several operating cycles of the crane, each mechanism has a time pause, and not all mechanisms are working continuously.
Working cycle The working cycle of a crane refers to the complete process from lifting a heavy object to starting the next lifting operation, including the normal operation and stop of the crane.
There are many types of heavy objects lifted by variable load cranes, some weighing hundreds or even thousands of tons, some as long as tens of meters, and irregular shapes, such as loose particles, hot melt state, flammable and explosive dangerous goods, etc.
Classification of cranes.
There are many ways to classify cranes, among which the most common one is to classify them according to their main uses and structural characteristics.
They can be divided into general cranes, construction cranes, metallurgical cranes, railway cranes, port cranes, deck cranes, etc.
According to the structural characteristics, they are divided into bridge cranes, cantilever cranes and cable cranes; rotating cranes and non-rotating cranes; fixed cranes and running cranes. Running cranes are divided into track-type (running on fixed tracks) and trackless (running without fixed tracks, supported by tires or tracks).
