Linear bearing is a kind of self lubricating properties of linear motion system, its difference with metal linear bearing is metal linear bearing is rolling friction, bearing and cylinder axis is point contact, so this kind of high speed movement, suitable for low load and linear bearing is a sliding friction, bearing and cylinder axis is surface contact, so the suitable for high load in the low speed movement. Linear bearing can withstand greater than metal bearing load, but the sport is sliding friction between bearing and shaft, so the linear bearing is limited by a certain movement speed, movement resistance than metal linear bearing, motor noise is lower than metal linear bearing, especially in the high speed, under the condition of linear bearing noise along with the speed of a very small effect. Linear bearing because of its internal chip removal tank design, so allow to be used in the occasion of dust is bigger, the dust in the process of movement from automatic chip removal tank out of the friction of the bearing body, linear bearing also allows cleaning, in the process of using sliding inside film even made special materials can be used in liquid to run for a long time.