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May 11, 2022 View:

How To Choose The Bearing Material Of Rotary Lobe Pump

Bearings are one of the lobe pump components. The selection of materials for bearings is generally divided into two categories: metallic materials and non-metallic materials. The following Ace lobe pump's will be introduced to you in detail.

I. Metal materials

Metal materials Commonly used sliding bearing metal materials are bearing alloys (also known as Bachmann or white alloys), wear-resistant cast iron, copper-based and aluminium-based alloys.

(1) Bearing alloy (also known as pasteurized alloy or white alloy) the main alloy components are tin, lead, antimony, copper. Antimony, copper, to improve the strength and hardness of the alloy. According to the national standard, the pasteurized alloy can be divided into two kinds of tin-based alloy and lead-based alloy. Lead-based alloys have lower strength and hardness than tin-based alloys, and are also less resistant to corrosion. Therefore, when using pasteurised alloys, tin-based alloys are usually used, and their common grades are ZSnSb11Cu6, ZSnSb8Cu4 and so on. Although the performance of lead-based alloys is not as good as tin-based alloys, but because it is more economical, so in order to meet the requirements of the working conditions still choose to use, the common grades ZPbSb16Sn16Cu2, etc.. However, most of the bearing alloy elements have a low melting point, so they are suitable for working conditions below 150°C.

(2) Copper-based alloys have high thermal conductivity and better wear resistance compared to steel. And copper-based alloys have very good processability and lubricity, its inner wall can be finely machined, and the shaft smooth surface contact. Copper-based alloys used as sliding bearing materials are: copper, antimony as the main component of brass; copper, tin as the main component of bronze; and copper-lead alloy (also known as lead bronze). Copper-based alloys have high strength, good thermal conductivity and wear resistance, and allow higher working temperatures than bainite alloys, but compliance, embeddedness and friction compatibility are not as good as bainite alloys. Commonly used tin, phosphorus tin bronze, suitable for medium-speed heavy load or impact load bearing; tin, zinc, lead tin bronze, suitable for medium-speed medium load bearing.

II. Non-metallic materials

(1) PTFE has excellent self-lubricating properties and high thermal stability. Its friction factor is small, non-absorbent, non-stick, non-combustible, can be used under the conditions of -180 ~ 250 ℃. However, there is also a large coefficient of linear expansion, poor dimensional stability, poor thermal conductivity and other disadvantages. To improve its performance, metal particles, fibres, graphite and inorganic fillers can be used to strengthen it.

(2) graphite is a good self-lubricating material, and because of its easy processing, and the more smooth grinding, so is the preferred material for bearings. However, its mechanical properties are poor, impact resistance and load bearing capacity is poor, only suitable for light load occasions. In order to improve its mechanical properties, commonly used some good wear resistance of fusible metal impregnation treatment. Commonly used impregnation materials are pasteurized alloy, copper alloy and antimony alloy, etc.. Dipped pasteur alloy graphite bearings allow the use of temperature 120 ~ 180 ℃, dipped copper alloy graphite bearings allow the use of temperature 300 ℃, dipped antimony alloy graphite bearings allow the working temperature of up to 500 ℃.

(3) rubber is a polymer with elastomer, with good elasticity and vibration absorption. However, its poor thermal conductivity, processing difficulties, allow the use of temperature below 65 ℃, and the need for continuous lubrication and cooling of circulating water, so generally rarely used.

(4) carbide has high hardness, wear resistance, good strength and toughness, heat resistance, corrosion resistance and a series of excellent performance, therefore, with its processing of high precision, smooth running, high hardness, good strength, durable, but expensive.

(5) Silicon carbide is a new type of synthetic inorganic non-metallic material. Hardness second to diamond, has excellent chemical corrosion resistance, wear resistance, high temperature resistance and mechanical strength, good self-lubricating properties, high temperature creep resistance, small friction factor, high thermal conductivity, low coefficient of thermal expansion and other characteristics, can be widely used in petroleum, metallurgy, chemical industry, machinery, aerospace and nuclear energy and other fields, commonly used as sliding bearings and mechanical seals of the friction sub-material. A large number of tests have shown that silicon carbide is currently the best material for frictional substrates, especially the best performance of pressureless sintered SiC and hot pressed sintered SiC.

The above is today's introduction, the specific choice of what material bearing, but also according to the specific working conditions to decide.