Summary:...
1. Oiliness and pressure resistance
Oiliness means that the gear oil can effectively make the lubricating oil film adsorb between the moving lubricating surfaces, and has the property of reducing friction. Anti-wear performance refers to the ability of the oil to maintain the oil film between the moving parts, which can effectively prevent the direct contact between metals. Adding some active substances with active molecules to the gear oil can improve its oiliness. The oiliness of these oily agents and The oxides on the metal surface will be adsorbed to form a firm oily film. The oily agent may also form a metal soap-type lubricating film with the oxides on the metal surface to strengthen the lubrication of the gear oil and prevent direct contact with the tooth surface. Reduces friction and thus reduces wear. Some gear drives often work under severe pressure lubrication conditions, and the pressure, sliding speed and local temperature they bear are very high, which requires the addition of pressure additives to the gear oil. Pressure additives are generally chemically active sulfur-phosphorus or sulfur-phosphorus-chloride-zinc oil-soluble compounds. These additives form iron chloride, sulfur, phosphorus compounds or complexes with tooth surface metals under temperature and pressure conditions, forming a melting point Inorganic film, this kind of pressure film has the performance of pressure resistance and impact load resistance, which can effectively prevent tooth surface abrasion and bite under load conditions.
2. Viscosity-temperature characteristics
The viscosity of various lubricating oils decreases as the temperature rises, and the smaller the decrease ratio, the better the viscosity-temperature performance. In particular, the operating temperature range of gear oils for automobiles and engineering machinery varies greatly. Therefore, it is hoped that the viscosity of gear oils will change as little as possible with temperature. If the viscosity-temperature characteristic of the gear oil is not good, the viscosity will be too high when starting, making it difficult to start, and the viscosity will be too small when the operation reaches the temperature limit. The viscosity of gear oil is also one of the important performances, and the viscosity has a great influence on the formation of oil film. Generally speaking, viscosity gear oil can effectively prevent gear and bearing damage, reduce mechanical operation noise and reduce oil leakage; low-viscosity oil has characteristics in improving mechanical operation efficiency, strengthening cooling and cleaning functions, and oil transmission. In order to reduce fuel consumption, the low viscosity of engine oil and gear oil has been promoted abroad. Low-viscosity gear oil is characterized by low agitation resistance of gear teeth, good low-temperature fluidity, and can be lubricated under low-temperature conditions. In recent years, some low-viscosity gear oils have also been produced. In order to improve their lubricating properties, some multi-effect additives have been added, which is very beneficial to reduce power loss. Of course, when it is used in its body, it is necessary to strengthen the sealing of the gear box to prevent gear oil from leaking.
3. Low temperature fluidity
Vehicle gear oil is required to maintain the necessary fluidity at low temperature. If the gear oil has wax precipitation at low temperature and the viscosity rises sharply, it cannot be lubricated effectively, and the starting torque at low temperature will increase, which will increase fuel consumption.
4. Thermal oxidation stability
Under harsh working conditions, under the catalysis of air, moisture and metal, the oxidation speed of gear oil is accelerated, the viscosity is increased, and insoluble and corrosive substances, as well as colloids and asphaltene are produced, and the properties deteriorate and are easy to emulsify and produce foam. Shorten oil change intervals. In order to delay the oxidation of gear oil, phenolic, amine or vulcanized antioxidant additives are generally added to the oil.
5. Rust and corrosion resistance
Rust resistance means that the gear oil protects the gears from corrosion, thereby improving the performance of the gears and prolonging their service life. During the operation of the gear, the moisture in the air condenses into water in the gear box, so the gear oil should have good rust resistance. In order to improve the rust resistance of gear oil, anti-rust additives such as sulfonate or fatty acid salt are generally added. Gear oil with pressure additives, because the pressure additives contain sulfide, sulfur is easy to corrode copper, therefore, anti-corrosion additives should be added to the gear oil, which can form a protective film on the metal surface to prevent corrosive substances from corroding the metal.
6. Anti-foaming
Gear oil is required to have good anti-foaming properties, so that under operating conditions, the foam generated during the vigorous stirring of the gears is small and easy to disappear. --
planetary gearbox in China
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