Lubricating oil is used in various types of machinery to reduce friction, protection of machinery and processing parts of the liquid lubricants, mainly lubrication, cooling, rust, cleaning, sealing and buffering functions. Lubricants accounted for 85% of all lubricating materials, a wide variety of brands, now the world's annual dosage of about 38 million tons. The general requirements for lubricants are:
1. Antifriction and abrasion resistance to reduce friction to save energy, reduce wear to prolong mechanical life, improve economic efficiency;
2. Cooling, require that the friction heat out of the machine at any time;
3. Sealing, requirements for leakage, dust-proof, channeling gas;
4. Anti-corrosive rust, require protection of friction surface from oil deterioration or external erosion;
5. Clean flushing, required to remove the friction area cleaning;
6. Stress dispersion buffering, decentralized load and mitigation shock and shock absorption;
7. Kinetic energy transmission, hydraulic system and remote control motor and friction stepless variable speed, etc.