Lubrication plays an important role in the normal operation of machinery and equipment.
(1) Reduce friction coefficient
Adding a lubricant between two relatively frictional surfaces to form a friction-reducing layer of a lubricant film can reduce the friction coefficient, feed frictional resistance, and reduce power consumption. For example, under good liquid friction conditions, the friction coefficient can be as low as 0.001 or even lower. The frictional resistance at this time is mainly the low shear resistance between the molecules sliding inside the liquid lubricating film.
(2) Reduce wear
The lubricant between the friction surfaces can support the wear caused by hard abrasion, surface rust, bite welding and tearing between metal surfaces. Therefore, by supplying sufficient lubricant between the friction surfaces, good lubricating conditions can be formed, the oil film can be prevented from being damaged, and the fitting accuracy of the parts can be maintained, thereby greatly feeding and abrading.
(3) Reduce the temperature
Lubricants can reduce the friction coefficient and support the generation of friction heat. We know that the machinery that works, overcomes the work done by friction, and all of it is converted into heat, part of it is diffused outward from the body, and part of it is constantly increasing the temperature of the machine. The centralized circulation lubrication system using liquid lubricant can take away the heat generated by friction, reduce the temperature, and make the machine control to operate within the required temperature range.
(4) Prevent corrosion and protect metal surfaces
Mechanical surfaces must inevitably come into contact with surrounding media (such as air, water, water vapor, corrosive gases and liquids, etc.) to rust and damage the metal surfaces of the machine. In particular, the corrosion and wear of high-temperature workshops and chemical plants in metallurgical plants are more serious.
(5) Cleaning and washing effect
The abrasive particles or foreign media generated by the friction pair during movement will accelerate the friction surface and wear. By using the fluidity of the liquid lubricant, the abrasive particles between the friction surfaces can be taken away, thereby reducing abrasive wear. In the pressure circulation system, the flushing effect is more significant. Process lubricants are used in cold rolling, hot rolling and cutting, grinding, drawing and other processing processes. In addition to cooling and cooling, it also has a good rinsing effect to prevent scratches on the surface by solid impurities and make processed products (steel ) The surface has better quality and surface roughness. For example, a suspension and dispersion additive is added to the lubricating oil used in the cylinder of an internal combustion engine, so that the gel and coke formed in the oil are washed from the cylinder wall and dispersed into small particles and suspended in the oil, along with the circulating oil filter Filtered to keep the oil clean, reduce cylinder wear, and extend oil change intervals.
(6) Sealing effect
For the cylinders and pistons of steam engines, compressors, internal combustion engines, etc., the lubricating oil can not only play a role of lubricating and reducing wear, but also enhance the sealing effect so that it does not leak air during operation and improve work efficiency.
Grease has a special effect on the formation of a seal, which can prevent water or other dust and impurities from entering the friction pair. For example, oil-immersed packing packed with grease can not only have a good lubrication effect on the seal of the pump shaft head, but also can prevent leakage and dust impurities from entering the pump body and play a good sealing role.
In addition, lubricants have the effect of reducing vibration and noise.