Powder metallurgy bearings are made by pressing, sintering, shaping and immersing metal powder and other anti-friction material powders. They have a porous structure. After being soaked in hot oil, the pores are filled with lubricating oil. During operation, they are pumped due to the rotation of the journal. Suction and friction heat, so that the metal and oil are heated and expand, and the oil is squeezed out of the pores, and then the friction surface acts as a lubrication. After the bearing is cooled, the oil is sucked back into the pores.

Powder metallurgy oil-impregnated bearings (oil-impregnated bearings) are a kind of porous alloy products in which the pores are impregnated with lubricating oil. When the shaft rotates, the temperature of the oil-impregnated bearing rises and pumps due to the friction between the shaft and the oil-impregnated bearing. The lubricating oil content seeps through the friction surface containing the inner or outer diameter of the oil-impregnated bearing when the shaft stops rotating. The lubricating oil flows back into the oil-containing bearing. Therefore, the consumption of lubricating oil is very small, and it can be used for long-term operation without supplying lubricating oil from outside. It is very suitable for occasions where it is difficult to supply oil and avoid lubricating oil pollution.

Oil-impregnated bearings are widely used in various types of machinery and equipment such as motor industry, automobile and motorcycle industry, home appliance industry, digital products, office equipment, power tools, textile machinery, packaging machinery and so on.

Generally speaking, powder metallurgy oil-impregnated bearings are mainly manufactured by pressing, sintering, shaping, and immersing raw material powder. Most of the machines nowadays have a relatively high degree of automation. The daily output is relatively large, and most of the products can be formed at one time, so the larger the batch, the better the production. Moreover, if the molds used today are a little less, it may make hundreds of thousands, and if there are more molds, it may make more than a million. However, the cost of the mold is relatively high, so it is difficult to make it if the batch is small, and the time to replace the mold is also long.

Generally speaking, powder metallurgy oil-impregnated bearings can be formed in one shot, basically without cutting. The cost is lighter than machining, and the material waste is less, so the price is cheaper. It is also in line with the current national policy of advocating energy conservation, so it is considered to be a technology that will not be outdated.

The base of powder metallurgy oil-impregnated bearings has been filled with lubricating oil by vacuum impregnation, and during operation, due to temperature rise and pumping, the lubricating oil in it will leak to the running surface, so it can be used without additional lubricating oil Occasions.