Rolling bearing using lubricant analysis

Rolling bearing using lubricant analysis

Lubricants used in rolling bearing are classified into grease and lubricating oil.

First, grease.

Grease is a mixture of lubricating oils, thickeners and additives at high temperatures. According to the type of thickener, grease can be divided into calcium-based grease, sodium-based grease, calcium-based grease, lithium-based grease, aluminum-based grease and molybdenum disulfide grease.

The main performance indicators of grease are penetration, dropping point, mechanical stability, oxidation stability and corrosion resistance. The choice of grease should be based on the working conditions of the rolling bearing, temperature and load.

The dropping point is generally used to evaluate the high temperature performance of the grease. The actual working temperature of the rolling bearing should be lower than the dropping point of the grease by 10-20°C, and the use temperature of the synthetic grease should be lower than 20-30°C. Penetration, indicating the hardness or load bearing capacity of the grease. Rolling bearings that work under heavy loads should use grease with low penetration. Calcium-based greases are not easily soluble in water and are suitable for wet, moist working environments. Sodium-based grease is easily soluble in water, suitable for dry, less water working environment.

General bearings use grease. The advantages of grease are: high oil film strength; good oil adhesion, not easy to lose, use for a long time; simple sealing, can prevent dust, moisture and other impurities from entering the bearing. The disadvantage is that when the rotation speed is higher, the friction loss power is larger.

Insufficient or excessive grease will lead to an increase in temperature rise during the operation of the bearing and accelerate wear. Therefore, the amount of grease to be filled should be moderate. In general, it is advisable that the filling amount be 1/3 to 1/2 of the space between the bearing and the housing.

Second, lubricants.

Lubricants include special mineral oils, vegetable oils and synthetic lubricants.

Lubricant performance indicators are viscosity, viscosity-temperature characteristics, acid value, corrosion, flash point, freezing point and so on.

Viscosity: refers to the relative motion of the lubricating oil inside the friction resistance, the size of the viscosity, a direct impact on the flow of lubricating oil and the ability to form a lubricant film between the friction surface. Therefore, viscosity is an important basis for selecting a lubricating oil.

Rolling bearing that operate at high or high temperatures are generally lubricated with oil. The advantages of oil lubrication are: reliable lubrication, low friction coefficient, good cooling and cleaning, and a variety of lubrication methods can be used to adapt to different working conditions. The disadvantage is the need for complex sealing devices and oil supply equipment.

When the rolling bearing is immersed in oil (oil valley lubrication), the height of the oil surface should not exceed the center of the lowermost rolling element. When the rotation speed is high, the oil dripping or oil mist lubrication should be used.

Huatao Bearings included Rolling Bearings, Thrust Bearings, Slewing Bearings, Joint Bearings. They are widely used in Industrial Gearboxes, Electric Motors, Industrial Rollers.