Selection of gearbox lubricating oil

Lubricating oil is the blood flowing in the spur gear box and plays a vital role.

First, the basic function is lubrication. The lubricating oil forms an oil film on the tooth surface and the bearing to prevent mutual friction between gear parts and reduce wear; At the same time, in the process of rotation, the lubricating oil can also take away a large amount of heat generated during the movement between the friction pairs to prevent burning the gears and bearings; In addition, the lubricating oil has a good anti rust and anti-corrosion function, avoiding the water and oxygen in the gearbox from corroding the gear parts; The lubricating oil can also take away impurities in the continuous flow process to ensure the cleanness of the gearbox. In the selection process of lubricating oil, the viscosity index of lubricating oil is the primary standard.

Viscosity refers to the resistance of fluid flow. For gear transmission system, viscosity is the most important physical property of lubricating oil. The lubricating oil must have proper fluidity to ensure adequate lubrication of components at various temperatures. However, the viscosity of lubricating oil decreases during use because low viscosity base oil is selected and more high molecular polymers are selected to improve the viscosity. During the use of lubricating oil, the molecular chain of high molecular hydrocarbon polymers is broken under the action of high temperature and high pressure for a long time, resulting in the decrease of viscosity. Therefore, the degree of viscosity change is related to the quality of lubricating oil.

Viscosity is the ability of lubricating oil to maintain its viscosity under various high and low temperature environments.

As for what kind of viscosity lubricating oil is used for the spur gear box, it is related to the environmental climate and the working state of the gear box. For example, the temperature in the south is higher than that in the north, and the viscosity of lubricating oil used in gear boxes under the same working conditions in winter and spring and autumn is slightly higher. In addition, the higher the operating temperature, the faster the speed of the gearbox. In order to maintain the high-temperature oil film stability, the higher the oil viscosity is required.

In addition, the quality of a lubricating oil is mainly evaluated by its viscosity stability. If the viscosity is large, the oil film is thick. It is suitable for spur gear boxes with high speed, high power and high temperature. If the viscosity is small, the oil film is thin. It is suitable for gear boxes with low speed, low power and low operating temperature. However, whether the viscosity is large or small, the oil must have better antioxidant and anti deterioration properties at high temperature.