Scraper

Self-propelled Scraper CAT 631G

Scraper - is a machine used for earthworks, related with building road and engineering facilities in mining. Scrapers are intended for: detachment ground and loading to own box, transportation and discharge anywhere. These machines combine features of: chipping of materials and transport, thus allows to achieve the best indicators of the cost compared with other machines.

Construction

Scrapers are made up of elements such as:

• tractor,

• frame - supporting structure, welded,

• lifting box system (via hydraulic actuators):

- direct,

- indirect,

• box (container),

• curtain (front wall of the container is closed for transport)

• emptying system,

• the charging system.

Division

Scraper

Scraper

Scrapers can be divided into the:

• chasis:

- without semitrailer,

- with semitrailer,

- self-propelled (wheeled or tracked),

- sets of scrapers (releasable during transport and inseparable),

- the pusher ( crawler tractor pushes scrapers),

• propulsion:

- on one axle of the tractor,

- on the two axles of the tractor,

- all-wheel of the tractor

• control of working systems:

- hydraulic,

- mechanical,

• on how to load:

- bottom-up (separated stream filling the box off the bottom by pressure),

- assisted system: conveyor, multibucket, telescoping boxes, push rod , gripping, cutting two-layer active,

• way of unloading:

- by tilting the container with excavated material (emptying gravity) rotating forward and backward,

- by rotating or sliding the bottom plate,

- by rotating or sliding component to pull out.

Work

Scrapers are used in earthworks in light and medium soils with distance to transport 150 - 5000 m. The thickness of the loading layer is from 20 to 60 cm. It regulates by the lowering or raising the box. Landing takes place at 15 - 40 m. Hard materials and brylaste are giving small filling, and also require large rimpull and heavily charges construction. Operating assembly of scraper is a box, having on the entire front width, knife which cuts layer of soil and filling box.

The filling process can be divided into three phases.

- phase I - Soil movement in opposite direction to the box,

- phase II - when the specified part of the box is full, the ground starts to move in the direction of movement of the box,

- phase III - Soil begins to move to the top of box.

Bibliography

• Henryk Hawrylak, Marian Jarząbek, Aleksander Sieczyński, Roman Sobolski, MASZYNY I PRACE POMOCNICZE W GÓRNICTWIE ODKRYWKOWYM, Wydawnictwo "Śląsk", Wyd. 1.