Needle roller bearings (needle bearing) are roller bearing with cylindrical rollers, and the rollers are thin and long relative to their diameters. This roller is called the needle roller. Despite having a smaller cross-section, bearings still have a high load bearing capacity, needle roller bearings are fitted with thin, long rollers (roller diameters d≤5mm,l/d≥2.5,l to roller lengths), so the radial structure is compact, and its inner diameter size and load capacity are the same as other types of bearings, with the smallest diameter, It is especially suitable for the supported structure with limited radial mounting dimensions.
Depending on the use of the situation, you can choose the bearing or needle roller and cage assembly without inner ring, at this time, the shaft neck surface and the outer surface of the casing hole are directly used as the inner and outer rolling surface of the bearing, in order to ensure the load capacity and the running performance is the same as that of the ring bearing, the hardness of the raceway surface of the shaft or casing hole, The machining accuracy and surface quality should be similar to the raceway of bearing rings. The bearings are only capable of withstanding radial loads.