Separable bearings are composed of raceway rings, needle rollers and cage assemblies, and can be arbitrarily combined with stamped thin raceway rings or cut-processed thick raceway rings. Non-separable bearings are integral bearings composed of precision stamped raceway rings, needle rollers and cage assemblies. They can withstand unidirectional axial loads. This type of bearing takes up little space and is conducive to the compact design of machinery. Most of them Only the needle roller and cage assembly is used, and the mounting surface of the shaft and housing is used as the raceway surface.