Major structural type

Physical ring needle roller bearings are composed of one or two rings and needle roller cage with a group of components. According to the different applications can be divided into an inner ring or without inner ring of the bearing. Therefore, the physical ring needle roller bearings to meet light weight, small footprint, transmission power requirements. Physical ring needle roller bearings with a smaller size and higher carrying capacity.
Major structural type
Outer double wall (or double lock ring) with cage needle roller bearings NA, NKI-typeInner and outer rings can be installed separately (with lock ring, full needle roller and cage), permissions, high speed, two kinds of single and double row.If the shaft can not be used as a raceway, ie If the shaft hardened impossible or uneconomical to use when grinding, you can use this type of needle roller backing bearings with inner ring.
Without inner ring needle roller bearings with cages
NA, NKI type bearings without inner ring is RNA, NK-type needle roller bearings.
Such bearings without inner ring for radial mounting dimensions restricted support structure to match the journal and bearing directly as rolling surface. Shaft as a raceway surface, the hardware must be quenched and polished, and only be processed to the appropriate size and shape accuracy, the entire needle roller bearings in order to extend the life and operation of high accuracy. Meanwhile, without inner diameter of the shaft can therefore be appropriate to increase, which also increases the rigidity.
With or without inner ring sealed needle roller bearings
Single or double sealed needle roller bearings can effectively prevent the intrusion of dirt, the bearing has filled the right amount of lithium grease. This kind of bearing inner ring width than the outer ring, which makes the bearing on the shaft relative to the bearing housing with a little displacement can assure a good seal and to prevent injury to the bearing contamination. Bearing inner ring also has lubrication holes can be configured according to the needs of the outer or inner relubrication