Micro bearings are a type of rolling bearing with a nominal outer diameter less than 26 millimeters, among which micro ball bearings with a metric outer diameter less than 9 millimeters are known as extra micro bearings in China. The main materials include carbon steel, bearing steel, stainless steel, plastic, and ceramics, with a minimum inner diameter of 0.6 millimeters. Common specifications include metric 68, 69, 60 series and imperial R series micro deep groove ball bearings, and derivative structures include ZZ steel plate dust covers, RS rubber seals, Teflon seals, and flange flanges. This bearing is composed of inner and outer rings, bearing balls, cages, and other components. Domestic manufacturers often adopt the production mode of purchasing rings for assembly. Mainly used in high-speed devices such as micro motors, instruments and meters, hard disk motors, computer cooling fans, etc., and gradually expanding to fields such as medical equipment, industrial robots, and autonomous driving [2-3]. Failure cases caused by the invasion of pollutants with over four causes, correct installation and protection can reduce the risk of damage [2]
