Powder metallurgy bearings are made by pressing, sintering, shaping, and immersing metal powders and other antifriction material powders into oil. They have a porous structure, and after being soaked in hot oil, the pores are filled with lubricating oil. During operation, due to the suction effect of journal rotation and friction heating, the metal and oil expand, squeezing the oil out of the pores, and the friction surface acts as a lubricant. After the bearing cools down, the oil is sucked back into the pores.

Powder metallurgy oil bearing (oil bearing) is a type of porous alloy product with lubricating oil immersed in the pores. When the shaft rotates, the friction between the shaft and the oil bearing increases the temperature of the oil bearing and the pumping effect. The lubricating oil seeps out of the friction surface of the inner or outer diameter of the oil bearing, when the shaft stops rotating. The lubricating oil flows back into the oil bearing. Therefore, the consumption of lubricating oil is very small and can be used for long-term operation without external supply of lubricating oil. It is very suitable for situations where oil supply is difficult and lubricating oil pollution is avoided.

Oily bearings are widely used in various mechanical equipment such as the motor industry, automobile and motorcycle industry, home appliance industry, digital products, office equipment, electric tools, textile machinery, packaging machinery, etc.

Powder metallurgy oil bearing is generally manufactured using raw material powder through processes such as pressing, sintering, shaping, and soaking. Nowadays, most machines are highly automated. The daily production is relatively large, and most products can be quickly formed, so the larger the batch size, the better the production. And if we use fewer molds now, we may produce hundreds of thousands of them, but if we have more molds, we may produce over a million. But the cost of the mold is relatively high, so it is difficult to make a small batch, and the time to replace the mold is also long.

Powder metallurgy oil bearing can generally be quickly formed without the need for machining. The cost is lighter than machining, and there is less material waste, making the price relatively cheap. It also conforms to the current national policy of advocating energy conservation, and is therefore considered a technology that will not fall behind.

The matrix of powder metallurgy oil bearing is already filled with lubricating oil by vacuum immersion method, and due to temperature rise and pump suction during operation, the lubricating oil in it will seep out to the operating surface, so it can be used in situations where no additional lubricating oil is added.