Roller bearing, speed reducer and industrial robot

The roller bearing is used for the speed reducer, the speed reducer comprises a cycloidal gear and a crankshaft, the cycloidal gear is provided with a through hole, the crankshaft is sleeved with the cycloidal gear through the through hole, the cycloidal gear is used for the speed reducer, the speed reducer comprises the cycloidal gear and the crankshaft, the cycloidal gear is provided with a through hole, and the crankshaft is sleeved with the cycloidal gear through the through hole. The pin roller is arranged between the cycloid gear and the crankshaft, the cycloid gear is arranged on the crankshaft in a sleeving mode through a through hole, and the pin roller bearing comprises the pin roller and a retainer. Each pin roller comprises an end surface and a circumferential surface, and the circumferential surface is in contact with the hole wall of the through hole and the outer circumferential surface of the crankshaft; the retainer is arranged on the end face of the roller and used for fixing the roller in the axis direction of the roller. According to the roller bearing, the retainer is used for fixing the roller, so that the roller is in direct contact with the cycloid gear and the crankshaft, the size of the roller can be increased, the load of the bearing is dispersed, and the bearing has higher bearing capacity. Meanwhile, the roller bearing is simple in structure, short in machining time, small in machining and assembling difficulty and low in cost.