What is an oil bearing? The sintered body made by powde […]
What is an oil bearing?
The sintered body made by powder metallurgy with metal powder as the main raw material for oil bearing is porous in nature and has the technical advantages of freely adjusting the number, size, shape and distribution of pores in 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. When the bearing is running, the temperature of the bearing rises. Because the expansion coefficient of the oil is larger than that of the metal, it enters the sliding surface automatically to lubricate the bearing. Oil bearing can be used for a long time by adding oil once, which is often used in inconvenient oiling occasions.
What is self-lubricating bearing?
Self lubricating bearing is divided into composite self-lubricating bearing, solid inlaid self-lubricating bearing, bimetal self-lubricating bearing and special material self-lubricating bearing. Different self-lubricating bearings are selected according to different uses and working conditions.
One of the major types of solid inlaid self-lubricating bearing (JDB) is a new type of bearing which has the characteristics of metal bearing and oil-free bearing. It is loaded by metal matrix and lubricated by solid lubricating material with special formula.
It has the characteristics of high bearing capacity, impact resistance, high temperature resistance and strong self-lubricating ability. It is especially suitable for heavy load, low-speed, reciprocating or swinging occasions which are difficult to lubricate and form oil film, and is not afraid of water erosion and other acid erosion and erosion. The products have been widely used in metallurgical continuous casting machine, steel rolling equipment, mining machinery, mold, 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 shaft sleeve.
Difference between oil bearing and self lubricating bearing
1. Oil bearing is made of metal powder with 10-40% structural clearance; the base of inlaid self-lubricating bearing is made by centrifugal casting; the density of matrix is relatively high, the bonding strength is higher than that of oil bearing, and the service life is longer than that of oil bearing;
2. The lubricating material of oil bearing is lubricating oil, and the oil film has enough 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; while the lubricating material of inlaid self-lubricating bearing is a solid lubricating material, which can still achieve good lubrication effect even under oil-free condition, which can ensure uninterrupted and sustainable lubrication, and its effective lubrication life is consistent with that of the substrate;
3. The lubricating oil in the oil bearing is volatile and easy to drain, and the lubricating oil film loses quickly under high temperature and high pressure, so it can't get the lubrication effect; In the graphite copper sleeve, the solid lubricant in the hole or groove transfers or reversely transfers to the friction surface, forming a solid transfer film with good lubrication, firm adhesion and uniform coverage on the friction surface, which greatly reduces the friction and wear. With the friction going on, the embedded solid lubricant is continuously provided to the friction surface, which ensures the good lubrication of the friction pair during long-term operation.