Reasons for wear of sliding bearing of main exhaust fan①

The wear of sliding bearing usually includes scratch, slight wear or severe wear. According to the actual wear condition of sliding bearing, the causes of wear mainly include the following aspects.
First, the load is too large. The main function of the sliding bearing is to bear the load. However, if the load it bears is too large, the sliding bearing will generate high heat during operation. Continuous high temperature will reduce the adhesion of metal, thus causing the sliding bearing surface to fall off and wear.
Second, foreign matters enter the sliding bearing. During the running of the sliding bearing, if the hard foreign matters enter the sliding bearing clearance, the hard foreign matters will rub with the bearing surface, thus causing wear of the bearing.
Third, the position of the sliding bearing is improper. When the mechanical management staff assembled the sliding bearing, they did not install the sliding bearing on the centerline, and the bearing was skewed. During the operation of the sliding bearing, serious friction would occur at one end. The heat generated by friction would fatigue the metal on the bearing surface, thus damaging the bearing.
Fourth, the bearing lubrication is insufficient. When maintaining the sliding bearing, the mechanical management personnel did not lubricate the sliding bearing in strict accordance with the relevant provisions, or the lubrication was improper due to work errors, which resulted in insufficient oil supply during the working process of the sliding bearing, resulting in wear, seizure, etc. due to the hydrodynamic oil film rupture. In addition, oil leakage, blocked oil circuit, oil pump obstacle, oil network blockage, pressure reducing valve spring failure and other reasons may lead to insufficient oil supply of sliding bearing during operation, and such oil cut-off failure may also cause wear and failure of sliding bearing.
Fifth, the corrosive effect of acid or cavitation. The sliding bearing needs to operate under the action of lubricating oil, but the acidic substances in the lubricating oil have corrosive effects on metals, making the surface substances of the sliding bearing gradually corroded, so that local or most of the surface substances of the bearing deteriorate. Cavitation means that the formation and collapse of hollow bubbles in the external oil will greatly increase the local pressure, increase the pressure at the local position of the sliding bearing, and make the sliding bearing overloaded, resulting in wear.