Looseness: The newly processed and assembled parts have deviations in geometric shapes and matching dimensions. In the early stage of use, they are affected by alternating loads such as impact and vibration, as well as heat, deformation and other factors, as well as excessive wear and tear. , It is easy to loosen the originally fastened parts.
Leakage phenomenon: due to the loosening of the machine parts, vibration and the influence of the machine’s heat, there will be leakage in the sealing surface of the machine and the pipe joints; some defects such as casting and processing are difficult to find during assembly and debugging, but due to the operation In the process of vibration and impact, this kind of defect is exposed, which manifests as leakage (seepage) of oil (water). Therefore, leakage is prone to occur during the running-in period.
Fast wear speed: Due to the influence of factors such as the processing, assembly and adjustment of new machine parts, the friction surface is rough, the contact area of the mating surface is small, and the surface pressure is uneven. During the operation of the machine, the concave and convex parts of the surface of the parts fit and rub against each other.The metal scraps that are ground down are used as abrasives and continue to participate in friction, which accelerates the wear of the mating surface of the parts. Therefore, the parts (especially the mating surfaces) are easily worn during the running-in period, and the wear rate is fast. If overloaded, it may cause damage to parts and cause early failure.
Poor lubrication. Due to the small fit clearance of newly assembled parts, and due to assembly and other reasons, it is difficult to ensure the uniformity of the fit clearance. Lubricating oil is not easy to form a uniform oil film on the friction surface to prevent wear. Thereby reducing the lubrication efficiency, causing the early abnormal wear of the machine parts. In severe cases, it will cause scratches or seizures on the friction surface of the precision fit, leading to failures.
