Cycloidal-pin wheel speed reducer and robot

The utility model relates to the technical field of speed reducers, in particular to a cycloidal-pin wheel speed reducer and a robot, and the cycloidal-pin wheel speed reducer comprises a stator, a rotor and a speed reduction assembly; the speed reduction assembly comprises a roller pin fixing seat, a cycloidal gear and an eccentric shaft; the cycloidal gear is fixedly sleeved on the eccentric shaft and is meshed with the roller pin structure on the inner wall of the roller pin fixing seat; the stator is used for driving the rotor to rotate; the rotor is used for driving the eccentric shaft to rotate, so that the eccentric shaft drives the cycloid gear to rotate; and the roller pin fixing seat is used for being inserted into an inner hole of the stator. Compared with the scheme that the roller pin fixing seat and the motor assembly are sequentially arranged in the axial direction in the prior art, the cycloidal-pin wheel speed reducer has the advantages that the roller pin fixing seat is inserted into the inn