Speed reducer and roller retainer thereof

The utility model provides a roller retainer of a speed reducer. The roller retainer comprises a first ring body, a second ring body and a plurality of connecting columns, the maximum outer diameter of the second ring body is smaller than the minimum inner diameter of the first ring body. Each connecting column is provided with a first end and a second end opposite to the first end, the first end of each connecting column is connected with the first ring body, the second end of each connecting column is connected with the second ring body, and every two adjacent connecting columns, the first ring body and the second ring body jointly form a containing space to contain a roller of a speed reducer. And the central axis of the pin roller mounted in each accommodating space is parallel to the rotating axis of the roller retainer. Therefore, the manufacturability of the roller retainer is improved, and an additional adaptive adjustment design for the crankshaft of the speed reducer is not needed. 本实用新型提供了一种减速机的滚子保