Silent Chain Factory Introduces The Reasons For The Wear Of The Sprocket

Silent Chain Factory introduces the reasons for the wear of the sprocket:

1. The greater the adhesive wear load and the higher the surface temperature, the more serious the adhesion phenomenon. Regarding metal materials with a certain hardness, the wear test is stopped at different pressures to obtain a graph of the relationship between wear rate and pressure. When the pressure reaches more than 1/3 of the hardness of the material, severe wear will occur. According to the stress distribution diagram, it can be seen that the maximum stress contact point is the maximum pressure, and its value is 884.4 MPa. Because 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 way of sprocket wear.

2. Contact fatigue and wear. The friction pair of the sprocket and the chain is an alternating contact stress, and it is easy to cause fatigue pitting on the friction surface. The index for judging the intensity of metal contact fatigue is the contact fatigue limit, that is, the maximum stress at which pitting corrosion does not occur under a certain number of stress cycles. The contact fatigue limit of 40Cr is σ0H=HRC17 +200 after surface quenching treatment, and σ0H=1016MPa is calculated. According to the stress distribution diagram, the maximum stress value of the sprocket socket is 884.4 MPa. Its value is very close to the contact fatigue limit allowed by the surface of the sprocket. At the maximum stress, it is easier to cause initial corrosion failure. However, due to the poor smooth condition of the sprocket and the chain, pitting was too late to form, which once caused abrasion. At this time, the main damage method is wear rather than pitting. Contact fatigue wear is the main way of sprocket wear, which fundamentally determines the service life of the sprocket.