Distinguish between self-lubricating bearings and oil-containing bearings
What is an oil bearing?
Oil-bearing bearings use metal powder as the main raw material, and the sintered body made by powder metallurgy is inherently porous, and has the technical advantages of freely adjusting the number, size, shape and distribution of pores during the manufacturing process. Using the porosity of the sintered body, it is impregnated with 10% -40% (volume fraction) lubricating oil and used in the state of self-supplying oil. During operation, the bearing temperature rises, and because the coefficient of expansion of oil is greater than that of metal, it automatically enters the sliding surface to lubricate the bearing. Oil-bearing bearings can be used for a long time after refueling. It is often used in situations where refueling is not convenient.
What is a self-lubricating bearing?
Self-lubricating bearings are divided into composite self-lubricating bearings, solid inlaid self-lubricating bearings, bimetallic self-lubricating bearings, special material self-lubricating bearings, according to different uses and working conditions, different self-lubricating bearings are selected.
One of the major types of solid inlaid self-lubricating bearings (JDB for short) is a novel lubricating bearing that combines the characteristics of metal bearings and oil-free lubricated bearings. The metal matrix bears the load, and the specially formulated solid lubricating material plays the role of lubrication.
It has the characteristics of high bearing capacity, impact resistance, high temperature resistance, strong self-lubrication ability, etc. It is especially suitable for heavy load, low speed, reciprocating or swinging occasions where it is difficult to lubricate and form an oil film, and it is not afraid of water erosion and other acid erosion And scouring. Products have been widely used in metallurgical continuous casting machines, rolling equipment, mining machinery, molds, lifting machinery, textile machinery, wind power generation, ships, steam turbines, turbines, injection molding machines and equipment production lines. The wear resistance is double that of ordinary bushings.
The difference between oil bearing and self-lubricating bearing
1. The oil bearing is a combination of metal powder with a structure gap of 10-40%; the self-lubricating bearing matrix is made of centrifugal casting; the matrix density is relatively high, the bonding strength is higher than the oil bearing, and the service life is longer than the oil bearing. Long
2. The lubricating material of the oil bearing is lubricating oil, and the oil film has sufficient thickness to eliminate the direct contact between the two friction surfaces. At this time, there is only friction between liquid molecules, so the friction coefficient is very small (f = 0.001 to 0.008), which significantly reduces friction and wear; and the lubrication material of the self-lubricating bearing is a solid lubrication material, even in the absence of oil Under the working conditions, the good lubrication effect that can still go can ensure that the lubrication is uninterrupted and sustainable, and its effective lubrication life is consistent with the life of the substrate;
3. The lubricating oil in the oil-bearing bearing is volatile and easy to lose. The lubricating oil film loses speed at high temperature and high pressure, and it cannot obtain the proper lubricating effect. In the graphite copper sleeve, the solid lubricant is rubbed, and the solid in the hole or groove The lubricant transfers or reverses to the friction surface, forming a solid transfer film with good lubrication, firm adhesion and uniform coverage on the friction surface, which greatly reduces friction and wear. As the friction progresses, the embedded solid lubricant is continuously provided on the friction surface, ensuring good lubrication of the friction pair during long-term operation.