Distinguish between self-lubricating bearings and oil-impregnated bearings
What is an oil-impregnated bearing?
The sintered body made of powder metallurgy method is porous and has the technical advantages of adjusting the number, size, shape and distribution of pores more freely in the manufacturing process. Using the porosity of the sintered body, it is impregnated with 10%-40% (volume fraction) of lubricating oil, and used in the state of self-oil supply. During operation, the temperature of the bearing rises, and since the coefficient of expansion of oil is greater than that of metal, it automatically enters the sliding surface to lubricate the bearing. Oil-impregnated bearings can be used for a long time with a single oil, and are often used in occasions where refueling is inconvenient.
What is a self-lubricating bearing?
Self-lubricating bearings are divided into composite self-lubricating bearings, solid inlaid self-lubricating bearing shafts, bimetallic material self-lubricating bearings, and special material self-lubricating bearings.
One of the major types of solid inlaid self-lubricating bearings (referred to as JDB) is a novel lubricated bearing with the characteristics of both metal bearing and oil-free lubrication bearing, which is loaded by a metal matrix and lubricated by a specially formulated solid lubricating material.
It has the characteristics of high bearing capacity, impact resistance, high temperature resistance, strong self-lubrication ability, etc., especially suitable for heavy load, low speed, reciprocating or swinging and other occasions that are difficult to lubricate and form oil film, and are not afraid of water erosion and erosion of other acids. The 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, water turbines, injection molding machines and equipment production lines. The wear resistance is twice that of ordinary bushings.
The difference between oil-impregnated bearings and self-lubricating bearings
1. The oil-impregnated bearing is made of metal powder combined, with a structural clearance of 10-40%; The inlaid self-lubricating bearing matrix is centrifugal casting; The density of the substrate is relatively high, the bonding strength is higher than that of oil-impregnated bearings, and the service life is longer than that of oil-impregnated bearings.
2. The lubricating material of the oil-impregnated 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 = 0.001~0.008), which significantly reduces friction and wear. The lubricating material embedded with the self-lubricating bearing is a solid lubricating material, which can still have a good lubrication effect even under oil-free conditions, which can ensure the uninterrupted and sustainable lubrication, and its effective lubrication life is consistent with the life of the matrix;
The lubricating oil in the oil-impregnated bearing is volatile and easy to lose, and the loss of the lubricating oil film is accelerated under high temperature and high pressure, and the due lubricating effect cannot be obtained; In the graphite copper sleeve, the solid lubricant is transferred or reversed to the friction surface through friction, and the solid lubricant in the hole or groove is transferred or reversed to form 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 supplied to the friction surface, ensuring good lubrication of the friction pair during long-term operation.
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Post time: Aug-04-2025
