The oil bearing itself is porous, and the sintered body is made of metal powder and other materials through powder metallurgy. Oil bearing is not only porous, but also the number, size and shape of pores can be controlled and adjusted in the manufacturing process, with high flexibility and freedom.

The porous structure of oil bearing makes it able to absorb lubricating oil well. After the oil bearing contains 10% to 40% lubricating oil, it can self lubricate during equipment operation. The application of oil bearing has a very obvious effect on the mechanical equipment that has a long running time and is difficult to maintain the lubrication state.

After the oil bearing is immersed in lubricating oil and put into operation, the temperature of the oil bearing will increase with the friction and heating of the mechanical equipment. Since the expansion coefficient of the oil is higher than the metal, the lubricating oil in the oil bearing will automatically enter the lubricating surface to lubricate the bearing. When the mechanical equipment stops running, the temperature of the oil bearing will drop, and the lubricating oil will be sucked back into the pores.

Oily bearings make use of the porous characteristics of various materials and the affinity of lubricating oil to keep the bearing itself able to work for a long time without external lubrication. However, this characteristic also makes the lubrication of oily bearings different from that of ordinary lubrication. In most cases, it will be in an incomplete oil film state, and the friction is mixed friction.