If the load on a deep groove ball bearing is too light during operation, sliding can occur between the balls and the raceways, leading to smearing (scuffing). This tendency is particularly pronounced in large deep groove ball bearings where the balls and cages are heavy. Bearings are also prone to rusting; there are many causes for this, but the most common factors encountered in daily life include the following:
1) Ingress of moisture, dirt, or other contaminants due to defective sealing;
2) Prolonged storage beyond the rust-prevention period without proper maintenance;
3) Excessive surface roughness of the metal;
4) Contact with corrosive chemical media; inadequate cleaning (leaving contaminants on the surface); handling with sweaty hands; or failure to package or install the bearing promptly after cleaning, resulting in prolonged exposure to air and subsequent moisture contamination;
5) Exposure to specific ambient temperatures, humidity levels, or environmental media; or the use of rust-preventive agents that have lost their effectiveness or fail to meet quality standards.
