Classification of bearings according to service characteristics

Bearings are classified according to their service characteristics

Bearings can be divided into: high temperature bearing, low temperature bearing, corrosion resistant bearing, sulfur resistant bearing, ant magmatic bearing, vacuum bearing, self-lubricating bearing, ceramic bearing, and high speed bearing etc.

1. High-temperature bearing

Bearings whose operating temperature is higher than 120℃ are high-temperature bearings. High temperature bearings are mainly used in aviation of jet engines, atomic reactor, X-ray tubes, and semiconductor components manufacturing equipment and various melting and coating, plating equipment.

2. Low temperature bearing

Bearings working at operating temperature below -60℃ are low-temperature bearings. Its typical application is all kinds of liquid gas pump, such as liquefied natural gas pump, liquid nitrogen (hydrogen, oxygen) pump, butane pump, rocket missile liquid pump, space vehicle and so on. The common low temperature bearing structure is single row deep groove ball bearing and cylindrical roller bearing.

3. Corrosion resistant bearings

Bearings for operate in corrosive medium, most of them are made of stainless steel, generally in the oxidizing medium, such as seawater, fresh water, water vapor and wet working environment, or in a certain concentration of acid or alkaline medium working bearing, are manufactured by stainless steel (9Cr18, 9Cr18Mo) system bearing ring and rolling body. The cage is made of 0Cr19Ni9 or 1Cr18Ni9 stainless steel. If working in corrosive medium with high ambient temperature, the bearing ring and rolling element are mostly made of high temperature stainless steel bearing steel (Cr14Mo4).For larger corrosion-resistant bearings, the semi-martensite and martensite stainless steel, such as 1Cr13, 2Cr13 or 3Cr13, are mostly used, which are made after surface nitriding treatment. The cage shall be made of solid cage such as stainless steel or beryllium bronze.

4. Sulfur resistant bearing

If the bearings used in hydrogen sulphide (HS) containing natural gas are of ordinary bearing steel, they are prone to hydrogen embrittlement and electrochemical corrosion. Therefore, the bearings made from 00Cr40Ni55A13 alloy should be used in such environments. The material is a nickel - chromium alloy; after heat treatment, the hardness is 51 ~ 55HRC, lower than ordinary bearing steel, so its bearing capacity is low. In addition, if there are scratches and scratches on the surface of bearing parts, it will also greatly reduce its sulfuric acid resistance performance. Special attention should be paid when the bearing parts are to be used.

5. Antimagnetic bearing

Antimagnetic bearings are made of non-magnetic materials with very low permeability. The most commonly used antimagnetic bearing material is beryllium bronze (QBe2).It has good mechanical, physical and chemical properties. After quenching and tempering, it has high strength, hardness, elasticity and wear resistance, and excellent corrosion resistance in atmosphere, fresh water and sea water.

6. Vacuum bearing

The bearings that work In the environment vacuum degree above 1.33pa, are vacuum bearing, which are mainly used in space technology and X-ray tube, radar multi-control tube, high power frequency and conversion magnetron, etc.

Deep groove ball bearings and angular contact ball bearings are mostly used for vacuum bearings. Rings and rolling elements are manufactured from bearing steel (GCr15) or stainless steel (9Cr18, 9Cr18Mo).In recent years, high pressure and high vacuum bearings are also made of new bearing alloy G60.

7. Self-lubricating bearings

Self-lubricated bearing is a special bearing which uses the cage as lubrication source to transfer lubrication and maintain the normal operation of the bearing. Self-lubricating bearings are mostly single row angular contact ball bearings and radial short cylindrical roller bearings.

8. Ceramic bearings

Ceramic bearing is a special purpose bearing, can be used in high speed, high temperature, low temperature, strong corrosion, strong magnetic field, vacuum, high pressure and other harsh working conditions. The main characteristics of ceramic bearing are: high bearing capacity, excellent heat resistance, high limit speed, small friction and low temperature rise, small friction loss, long durability, high corrosion resistance, good insulation, low magnetic permeability, and good self-lubrication.

9. High-speed bearing

Rolling bearings with Dm• N value exceeding 1.0×106mm• R /min are usually called high speed bearings. Here, Dm is the average diameter of the rolling body, and n is the rotation speed of the inner ring. At present, in practical application, the Dm• N value of high-speed bearing has reached 3.0×106mm• R /min. At the beginning of this century, the Dm• N value of high-speed bearing has reached 3.5×106mm• R /min.