An excavator is the most common type of earthmoving self-propelled machinery, it is designed for digging, mining, excavating, excavating, digging pits. Machines can work with rocks, soft soils, fossils, ore rocks.
Excavators are machines with attachments designed for simultaneous cutting and excavation. There are single bucket and bucket excavators. Shovels are cyclical machines. They periodically repeat the same movements. Shovels produce more actions; they can be milling, scraper and directly bucket.
Excavators with one bucket are classified according to their purpose. Construction-universal - the most common, are used for most earthworks. Mining excavators are needed for the development of coal and ore deposits. Using overburden work with the upper layers of the soil.
Bucket wheel excavators belong to bucket machinery. What is the difference? Why is it better to prefer this type of technique for some types of work?
A bucket wheel excavator is used for overburden mining and soil extraction. Moreover, they can perform both the first and second type of work with either upper or lower scooping. This type of earthmoving machine is used to transport rocks or fossils, dig channels, dig trenches, load rocks or remove them into a dump.
A rotary excavator has a higher efficiency, and therefore, soil development becomes less costly, but more productive. The number of bucket fillings in such models is much smaller, the bucket emptying is better, and this also increases productivity and reduces energy consumption.
A bucket wheel excavator can have a rail walking or caterpillar track. For removal or opening of the rock, construction of dumps, loading and other works, it is equipped with an arrow (retractable or non-retractable).
The idea of creating a rotary excavator came from ancient times: if you look closely at the car, you will notice a great resemblance to the ancient wheel with which our ancestors raised water. Leonardo da Vinci was the author of the scoop wheel, the scheme of which formed the basis for the drawings of the self-propelled vehicle.
A bucket wheel excavator works with soil or rock buckets that are mounted on a wheel (rotor). The rotor, in turn, rotates in the direction that is most effective for contact with the face. For the upper scooping - this direction coincides with the clockwise direction, for the bottom - the opposite.
During operation, the executive body of a bucket wheel excavator can move horizontally and vertically.
Machines adapted for lateral or radial digging are distinguished by the method of feeding to the face, productivity, magnitude of the change in horizon, type of movement (running gear).
In addition, the rotors are different in the way they use when unloading buckets. Some are unloaded due to the force of gravity, which acts on the rock when the bucket passes through the upper point of the unloading zone. In inertial machines, the bucket is unloaded by centrifugal force, which throws the rock out of the bucket. In order for the inertial unloading to be constant, it is necessary to provide such a frequency of rotation of the rotor so that the centrifugal force becomes greater than the force of gravity.
Raising or lowering the arrows (dump and rotor) is carried out through the tackle with the help of the counterweights installed on the boom. The tackle system, the mast at which the boom is supported, and the turntable together constitute the excavator add-on.
The upper structure with the help of a rotary support device is tightly mounted on the chassis, which can be rotated 360 °. The dump conveyor is equipped with its own rotation drive. This drive allows its boom to deviate from the longitudinal axis by 270 °, while maintaining a predetermined position in space, regardless of how the rotary boom is located.