First of all, to understand the basic structure of needle roller bearings, mainly including ring, roll body, cage and other parts, because the efficacy of each part and its bearing force are different, so when choosing materials, we should be particularly cautious, must meet the performance requirements of each component of needle roller bearings.
1. Rings and rollers of needle roller bearings
When needle roller bearings are in running state, one side of the ring and roll body repeatedly bears high contact pressure, while the other side carries out rolling contact with sliding.
From this point of view, needle roller bearing rings and rollers need materials with good dimensional stability, fatigue strength, high hardness and good friction resistance. Usually, high carbon chromium bearing steel is used to make them. At the same time, according to different uses, the performance of materials in impact resistance, heat resistance and corrosion resistance should also be considered.
If the actual requirements require better impact resistance, chromium steel, chromium-molybdenum steel, nickel-chromium-molybdenum steel and other bearing materials can be selected, and after carburizing and quenching treatment, the steel has a hardening layer from the surface to the appropriate depth, thus further improving its impact resistance.
Some needle roller bearings are also made by vacuum degassing treatment, so that the rolling fatigue life of bearings is significantly increased, which is helpful to prolong the service life of needle roller bearings.
2. Holder Material of Needle Roller Bearing
For needle roller bearings, one side of the cage slides in contact with both sides of the ring and roll body, or one side of the cage slides; the other side bears tension and compression. But when choosing the material, we must combine the actual use. If it is used for stamping, we should choose low carbon steel as its material. If it is used for cutting cage, high strength brass, carbon steel and synthetic resin are all good choices.
