What is the difference between a needle roller bearing and a cylindrical bearing

The needle bearing is equipped with a thin and long roller (the roller diameter D < < 5mm, L/D > 2.5, L as the roller length), so the radial structure is compact, its inner diameter and load capacity are at the same time with other types of bearing, and the outer diameter is small, especially suitable for the bearing result of the restricted radial installation. According to the different use situation, the bearing or needle roller and the cage assembly can be selected. At this time, the surface of the shaft neck and the outer surface of the shell are directly used as the inner and outer rolling surface of the bearing, so as to ensure the same load and running performance as the bearing ring bearing, the hardness of the surface of the axle or the outer shell hole raceway, and the machining accuracy. And the surface quality should be similar to the raceway of the bearing ring. This kind of bearing can only bear radial load.