Tham khảo tài liệu 'volume 18 - friction, lubrication, and wear technology part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Cooler Fig. 2 Circulating oil lubrication system Circulating systems are usually fitted with filtration systems to remove bearing wear and environmental contamination from the lubricant. The use and maintenance of clean oil is of utmost significance in obtaining extended bearing life. Generally increased filtration is beneficial to bearing lifetime if the filter is properly chosen and maintained. A 10 . - m mil filter is a good choice. The sump should be of adequate capacity to contain oil for at least 30 min in order to provide settling of contaminants. Oil Jet. The amount of oil for very high speed operation should be minimized to limit bearing temperature rise. A useful method for this case is oil jet lubrication. As shown in Fig. 3 a jet of oil under pressure is directed at the side of the bearing between the inner ring outside diameter and cage inside diameter. The oil jet velocity must be high enough 15 m s or 50 ft s to penetrate the turbulence generated by the bearing rotation. Fig. 3 Oil jet lubrication of rolling bearings Oil mist lubrication has been found to be useful in either high-speed applications or those in which the bearing housing is surrounded by water and grit. Mist lubrication is suitable for both horizontal and vertical shafts. Very small accurately metered amounts of oil are directed at the rolling element by compressed air. By minimizing oil quantity operation can occur at a lower temperature and higher speed than is possible using any other method of lubrication. Oil consumption is consequently low and the air flow prevents the entrance of grit and subsequent wear. Several atomizer designs are available from a variety of manufacturers. Single-pass lubrication systems can be effective when minimum bearing friction is essential loads are low and speeds are moderate. A minimum spray of fluid mist is delivered to the bearing contacts. Churning and resultant losses are eliminated and low usage permits discarding the lubricant after a .
