Solid ferrule needle bearings consist of one or two ferrules and a needle set with a cage. Depending on the application, it can be divided into bearings with or without inner ring. Therefore, the physical ferrule needle roller bearing can meet the requirements of light weight, small space occupation and large transmission power. Solid ferrule needle bearings have a small volume and high load carrying capacity. Structure type outer ring double rib (or double lock ring) with cage needle roller bearings NA, NAV, NKI type can be installed inner ring and outer ring (with lock ring, full set of needle roller and cage), high speed, It is divided into single column and double column. If the shaft cannot be used as a raceway, that is, if it is impossible or uneconomical to harden the shaft, such a needle bearing with an inner ring can be used.
Features NA, NKI bearings are RNA and NK needle bearings without inner ring. This type of bearing has no inner ring and is suitable for a support structure with a limited radial mounting size. The journal that matches the bearing directly acts as a rolling surface. As the axis of the raceway surface, the hardware must be hardened and ground, and the entire needle roller bearing can only have a high life and running accuracy when it is machined to the appropriate size and shape accuracy. At the same time, since there is no inner ring, the diameter of the shaft can be appropriately increased, thereby also increasing the rigidity.