Corresponding sealing devices are installed on both end faces of rolling bearings. With dust cover and sealing ring, the two properties are different, one is dust-proof and the other is sealing. What are the common materials of this sealing device? There are mainly the following.

Nitrile rubber

Nitrile rubber is a general sealing material. It is a rubber synthesized from acrylonitrile and butadiene. It has good resistance to the following media:

Most mineral oils and mineral oil-based greases, general fuels such as gasoline, diesel and light civil fuels, animal oils, vegetable oils and fats, and hot water.

Nitrile rubber seals also allow bearings to operate for short periods of time without oil. The allowable operating temperature range is - 40 to 100 ℃. It can withstand temperatures up to 120 ℃ in a short time. However, it is not suitable to operate at higher temperatures because nitrile rubber will harden.

Hydrogenated nitrile rubber

Hydrogenated nitrile rubber has more wear resistance than nitrile rubber, so the seals made of this material have longer service life. In addition, hydrogenated NBR has stronger resistance to heat, ageing and hardening in hot oil or ozone. The maximum allowable working temperature of hydrogenated nitrile rubber is 150 ℃, which is much higher than that of nitrile rubber.

Fluororubber

The main characteristics of fluororubber are high temperature resistance and chemical corrosion resistance, good anti-aging and ozone resistance, and low porosity. Even under very bad working conditions, fluororubber still has excellent wear resistance. It can withstand the working temperature of 200 ℃ or below. The seal made of this material allows the bearing to run for a short time without oil.

Fluororubber also has excellent resistance to various media, including oil and hydraulic oil, fuel oil, lubricant, inorganic acid, aliphatic hydrocarbon and aromatic hydrocarbon. Fluororubber should not be used when there are esters, ethers, ketones, some amines and high-temperature anhydrous hydrogen fluoride and other compounds. If the seal made of fluororubber is exposed to open fire or high temperature above 300 ℃, it will endanger health and the environment! Even after cooling, they are dangerous.

Importance of bearing sealing device

Seals are important for lubricant cleaning and bearing life.

Function of bearing sealing device

The function of the seal is to prevent the loss of lubricant and prevent pollutants from entering the space that needs to be protected.

Characteristics of bearing sealing device

1. Have sufficient deformation capacity to compensate for irregular surfaces;

2. Have enough strength to withstand the pressure in the work;

3. Able to withstand a large working temperature range;

4. Chemical resistance;

5. Minimum friction, friction heat and wear during operation.