Linear bearing is a low-cost linear motion system, which is used for infinite stroke and cylindrical shaft. Because the bearing ball is in point contact with the shaft, the service load is small. The steel ball rotates with minimal friction resistance, so as to obtain high-precision and stable motion. Linear bearings are widely used in precision equipment such as electronic equipment, tensile testing machines and digital three-dimensional coordinate measuring equipment, as well as sliding parts of industrial machinery such as multi axis machine tools, punches, tool grinders, automatic gas cutting machines, printers, card sorting machines, food packaging machines and so on.