Needle roller and cage assembly (needle roller bearing) is an independent rolling element. The distance between the two guide surfaces of the cage is wide, which can not only guide the needle accurately, but also maintain the correct position of the needle roller. This kind of bearing is suitable for the occasions where the shaft and seat hole can be used as raceway. Only by machining the raceway of the shaft and bearing seat hole to the specified dimensional accuracy and geometric accuracy, the high rotation accuracy of the minimum space can be ensured.