Excavators are devices belonging to construction special equipment. The name of these machines is derived from the combination of two Latin words - ex and caveo, which means digger.

These machines have high rates of digging ability, but the disadvantages include their low transportation capacity. Excavators form several groups depending on their power. There are the following types of excavators: wheeled, crawler, mini-excavators and backhoe loaders. Also, this special equipment is classified by the performance of operations and is used actively together with the lease of Liebherr in Moscow.

If all operations are performed in a given order and repeated after some time, then such excavators are referred to the class of cyclic action, and if all operations are performed simultaneously - to the class of continuous action. To machines of cyclic action, as a rule, single-bucket excavators, and to machines of continuous action - scraper, multi-bucket and milling excavators. Multi-bucket and single-bucket excavators are floating and land-based. Onshore machines have rail, pneumatic wheel, caterpillar and walking devices.

Excavator mechanisms are powered by diesel, steam, electric or carburetor engines. Electric and diesel engines are among the most economical, and the choice of engine is determined by the conditions in which the excavator will operate. If the work is carried out in a quarry, it is better to use electric motors due to the cheapness of electrical energy, and if there is road construction, where the excavator will be often transported, diesel engines will serve as a more appropriate solution. Excavators are also categorized according to the following criteria. If one engine drives all mechanisms, then the data drive is called single-engine, and if a group of mechanisms or each mechanism acts with a separate engine, then the data drive is called multi-motor.

The following types of drives are used to transmit motion to the working mechanisms from the engine. Hydraulic volumetric - the role of the drive is a hydraulic pump, hydraulic cylinders and oil lines. Mechanical - the motion is transmitted by gears, shafts, worm pairs and chain drives. Hydromechanical - when motion is transmitted by a torque converter in combination with a mechanical transmission. Mixed - consisting of different types of drives. Thus, the classification of excavators is as follows: by the type of power equipment (diesel, electric, etc.), by the method of movement (land and floating), by the number of engines