Scraper conveyor is a kind of continuous transportation equipment which transports bulk materials by means of moving scraper chain. The scraper conveyor is mainly used for the transportation of the medium and low thick coal seam economic general mining face. The product has the characteristics of compact structure, simple, stable transmission, convenient installation and maintenance, reliable work, flexible process layout, etc.; it can not only transport horizontally, but also transport obliquely; it can be used by a single machine or multiple sets in combination. Sprocket is one of the important parts of the scraper conveyor. Its characteristics have a direct impact on the service life of the scraper conveyor. In the analysis of crocket wear, the transmission of crocket is a common traction crocket, which has a relatively large sliding motion at the meshing position. The working conditions are bad, and it will produce serious wear.

Cause of wear

The reasons for the serious wear of the socket are as follows:

(1) The larger the adhesive wear load, the higher the surface temperature, the more serious the adhesive phenomenon. For a certain hardness of metal materials, the wear rate and pressure curves are obtained by wear tests under different pressures. When the pressure reaches more than 1 / 3 of the material hardness, serious wear will occur. According to the stress distribution diagram, it can be seen that the contact point of high stress is the place with high pressure, and its value is 884.4 MPa. As the quenching hardness of the chain socket is hrc48-52, the corresponding hardness value is 4800mpa. Therefore, the pressure is far less than 1 / 3 of the hardness of the material, so adhesive wear is not the main form of sprocket wear.

(2) Contact fatigue wear

It is easy to form fatigue pitting on the friction surface of sprocket and chain. The index to judge the metal contact fatigue strength is the contact fatigue limit, that is, the large stress without pitting under a certain number of stress cycles. The contact fatigue limit of 40Cr after surface quenching is σ 0h = hrc17 + 200, which is calculated to be σ 0h = 1016mpa. According to the stress distribution diagram, the large stress value of the socket is 884.4 MPa. Its value is close to the allowable contact fatigue limit of the spruck surface, and it is easy to cause pitting failure at high stress. However, due to the poor lubrication conditions between the sprocket and the chain, pitting has not been formed, which has caused wear. At this time, the main form of damage is wear rather than pitting. Contact fatigue wear is the main form of sprocket wear, which basically determines the service life of sprocket.