Roller bearing and mounting method thereof

The invention provides a roller bearing and a mounting method thereof. The roller bearing comprises a retainer, wherein through grooves which run through the retainer in the radial direction are circumferentially distributed in the retainer, a roller is arranged in each through groove, each through groove is provided with a stop structure for preventing the roller from outward dropping along the radial direction of the retainer, and the roller bearing also comprises an inner supporting body which is arranged coaxially with the retainer body and used for preventing the inward dropping of the roller body along the retainer, and the inner supporting body can be ejected along the axial direction of the retainer. The through groove of the retainer is provided with the stop structure, the stop structure only stops the outward dropping of the roller in the radial direction, compared with the existing bearing retainers, the through groove is free from stopping the inward dropping of the roller in the radial direction