The overhead crane is generally composed of a bridge (also called a cart). It is composed of hoisting mechanism, trolley, cart moving mechanism, control room, trolley conductive device (auxiliary slide wire), overhead crane main power conductive device (main slide wire) and other parts.

The work type of overhead crane is determined according to its load rate and busyness of work. It can be divided into four types: light, medium, heavy and extra heavy.
1. Lightweight. Running speed is low, and the number of uses is small? There are few opportunities for full load, and the power-on duration rate is 15%. Used in workplaces that are not stressful and heavy. Such as cranes used for installation and maintenance in hydropower stations and power plants.
2. Intermediate. It often works under different loads, the speed is medium, the work is not too heavy, and the power-on duration rate is 25%, such as the cranes used in general machining workshops and assembly workshops.
3. Heavy class. The work is heavy, often working under heavy loads, and the power-on duration rate is 40%, such as cranes used in metallurgical and foundry workshops.
4. Extra heavy class. The rated load is often hoisted, and the work is particularly busy, and the power-on duration rate is 60%, such as an overhead crane dedicated to metallurgy.
The above is the classification of overhead crane work types, I hope to help everyone.