What is the difference between needle roller bearings and cylindrical bearings

The needle roller bearing is equipped with thin and long rollers (roller diameter D ≤ 5mm, L/D ≥ 2.5, L is the length of the roller), so the radial structure is compact. Its inner diameter size and load capacity are the same as other types of bearings, and its outer diameter is the smallest. It is particularly suitable for support results with limited radial installation dimensions. According to different usage scenarios, bearings or needle and cage components without inner rings can be selected. At this time, the journal surface and shell hole surface that match the bearing directly serve as the inner and outer rolling surfaces of the bearing. To ensure the same load capacity and operating performance as bearings with rings, the hardness, machining accuracy, and surface quality of the shaft or shell hole raceway surface should be similar to the raceway of the bearing ring. This type of bearing can only withstand radial loads.