Needle Roller Bearings with an Inner Ring are a type of roller bearing that utilizes small, cylindrical rollers with a high length-to-diameter ratio (needle rollers). The key feature of this design is the inclusion of a dedicated, hardened inner ring that serves as the precision raceway for the needle rollers. This inner ring is typically mounted onto a shaft. The presence of the inner ring protects the shaft from wear and allows the bearing to handle higher loads and higher speeds compared to needle roller cages without an inner ring. It also simplifies shaft design, as the shaft itself does not need to be hardened and ground to the same precise tolerance, which reduces overall cost.
