According to the main criteria of bearing working capacity, the material used to make the bearing should have a certain load capacity, embedding, thermal conductivity, low coefficient of friction, smooth surface, wear resistance, fatigue resistance and corrosion resistance. No single material can fully meet all requirements, which is why the compromise method is often used in most designs. Briefly introduce the performance and application of several bearing materials.
Bearing alloys (babbitt alloys) are widely used. They are usually of two types: tin-based bearing alloys and lead-based bearing alloys. They have the characteristics of fast running-in, it is easy to make the surface very smooth, and they are usually used as bearing linings on the steel bearing shell base. Babbitt bearings have good adaptability, and have automatic adjustment characteristics for smaller misalignment or defective shafts. Because the appropriate amount of dust or foreign debris entering the lubricant can be absorbed by this soft material to prevent the shaft from gluing and breaking, this embedding makes them an excellent bearing material. The journal material can be soft steel, hard steel or cast iron.
Bronze bearings are suitable for low-speed and heavy-load occasions with good neutrality of shafts and bearings. They can be made of a variety of alloy components to obtain various physical properties.
The bearing capacity of this kind of bearing is higher than that of bearing alloy, and its adaptability is poor. Therefore, it is used for shaft rigidity and good neutrality.
Cast iron bearing materials are widely used in less demanding applications. The hardness of the journal must be higher than the hardness of the bearing pad. The working surface should be carefully run-in with a mixture of graphite and oil. Requires good alignment between the journal and the bearing.