Material of plastic bearings

1. Precision all plastic bearings

POM and PA materials have good mechanical strength and wear resistance, making them suitable for making relatively precise plastic bearings. Their good self-lubricating performance and low friction coefficient, while maintaining the traditional advantages of plastic bearings, can be applied to precision and high-speed operation. POM plastic bearings are the most widely used among all plastic bearings. Generally, POM or PA is used for the inner and outer ball materials, and the retainer is made of glass fiber reinforced nylon 66 (GRPA66-25). The ball bearings are made of glass, stainless steel or ceramic balls, which perform well in alkaline environments but are not suitable for operation in acidic corrosive environments.

2. Corrosion resistant plastic bearings

As the most typical varieties of fluoroplastics, PTFE and PVDF have the best corrosion resistance, among which PTFE has the best corrosion resistance among all known engineering plastics. It can be used in all concentrated acid and alkali applications, including HF and fuming sulfuric acid nitric acid (over 98%), and has good high temperature performance. PTFE has been proven to be suitable for high temperatures up to 180 ℃, and PVDF can also be used up to 150 ℃. However, PTEF materials have extremely low mechanical strength, poor dimensional stability, and large temperature deformation. Compared with PVDF, PVDF has better comprehensive performance. Generally, PTFE or PVDF is selected as the inner and outer ring materials, PTFE or PVDF is used as the cage material, and glass or ceramic balls are used as the ball bearings.

3. Acid alkali resistant plastic bearings

HDPE, PP, and UPE materials have been proven to be suitable for relatively weak acid-base cross environments (tested OK with 30% Cucl2 solution and 30% NaoH solution), making them suitable for most acid/alkali/salt/solvent/oil/gas and seawater corrosion environments. It has the oil-free self-lubricating and magneto electric insulation properties of general plastic bearings, but its mechanical strength is low and it is prone to deformation, so it is not suitable for high loads and high speeds. In comparison, UPE material has better strength, low friction characteristics, and low-temperature application characteristics (as low as -150 ℃). Generally, the inner and outer ring materials are made of HDPE, PP, or UPE, and the cage material is made of HDPE, PP, or UPE. The ball bearings are glass balls, stainless steel balls, or ceramic balls.

4. PEEK/PI plastic bearings (high-temperature resistant plastic bearings)

PEEK and PI, as emerging engineering plastic materials, have been proven to have the best mechanical strength, dimensional stability, and high temperature resistance among all known engineering plastics. PEEK can be used for a long time at a temperature of 260 ℃, while PI can be used for a long time at a temperature of up to 300 ℃. It also has excellent corrosion resistance and can operate freely in medium strength acid-base corrosion environments. Therefore, it is generally used to make bearings that require precise operation in harsh environments. The disadvantage is that the material itself is relatively expensive, so the cost of use is high. Generally, PEEK or PI is used for the inner and outer ring materials, PTFE, PEEK or PI for the cage material, and ZrO2 or Si3N4 ceramic balls are used for the ball bearings.

5. Plastic bearing seat and plastic outer spherical bearing

Plastic belt seat bearings are characterized by their light weight, easy installation, maintenance free, and lack of shock absorption and impact resistance compared to commonly used cast iron or stamped seats. With the continuous development of new materials, they are increasingly being widely used in engineering. For different situations, plastic outer spherical bearings can be made of different materials such as POM, HDPE, PP, UPE, PTFE, etc. The plastic bearing seat is generally made of PBT material.