What is the structure and material of rolling bearings

Rolling bearing is a precision mechanical component that converts the sliding friction between the running shaft and the shaft seat into rolling friction, thereby reducing friction losses.

Rolling bearings generally consist of four parts: inner ring, outer ring, rolling element, and retainer. The function of the inner ring is to match and rotate with the shaft; The function of the outer ring is to cooperate with the bearing seat and provide support; Rolling elements are evenly distributed between the inner and outer rings using a cage, and their shape, size, and quantity directly affect the performance and service life of rolling bearings; The cage can evenly distribute the rolling elements, prevent them from falling off, and guide them to rotate for lubrication.

Material of rolling bearings:

The ring and rolling element of a rolling bearing repeatedly bear high contact pressure while making rolling contact accompanied by sliding. Retainer, with one side sliding in contact with the sides of the ring and rolling element, or one side sliding in contact, and one side bearing tensile and compressive forces. Therefore, the material, performance, and main requirements for the bearing ring, rolling element, and retainer are as follows

The required performance of materials for rings and rolling elements:

The required performance of high rolling fatigue strength, high hardness, high wear resistance, and high retainer material:

Good dimensional stability, high mechanical strength, and good processability are also required. According to different uses, it is also required to have good impact resistance, heat resistance, and corrosion resistance.

Material of Ferrule and Rolling Element:

Rings and rolling elements are usually made of high carbon chromium bearing steel. Most bearings use SUJ2 from JIS steel grades. SUJ3 is used for large bearings.

The chemical composition of SUJ2 has been standardized as a bearing material in various countries around the world. For example, it belongs to the same type of steel as AISL52100 (USA), DIN100Cr6 (West Germany), BS535A99 (UK), etc.

When further impact resistance is required, chromium steel, chromium molybdenum steel, nickel chromium molybdenum steel, and carburizing quenching are used as bearing materials to create a hardened layer from the surface to the appropriate depth of the steel. Carbonized bearings with appropriate hardening depth, fine structure, suitable surface and core hardness have better impact resistance than bearings made of bearing steel. The chemical composition of steel used in general carburized bearings is similar.

Vacuum degassing treatment has been implemented, resulting in high purity, low oxygen content, and good quality of the materials used. Furthermore, appropriate heat treatment was adopted to significantly improve the rolling fatigue life of the bearings.

In addition to the above-mentioned steel grades, high-speed steel with excellent heat resistance and stainless steel with good corrosion resistance are also used for special purposes.

Retainer material:

The material for stamping the cage is made of low-carbon steel. According to different uses, brass plate and stainless steel plate are also used. The material for cutting the cage is high-strength brass, carbon steel, and synthetic resin is also used.

For more bearing information, please follow the Li Gong Bearing website: www.ligzz.com