Speed reducer of the cycloidal type for robots and other industrial manipulators

In a speed reducer of the cycloidal type for industrial manipulators which reducer includes a frame supporting a fixed ring member having a first plurality of annularly spaced teeth, a rotatable input shaft, means for rotatably engaging the input shaft to at least one eccentric means which surrounds the input shaft, cam means having inner and outer surfaces, the cam means being driven by the eccentric means and having a second plurality of teeth on the outer surface thereof which are engagable with the teeth of the fixed ring member, the first plurality of teeth being greater in number than the second plurality of teeth, a rotatable drive plate including an output means, actuation means carried by the drive plate for drivingly connecting said drive plate to the cam means, and the actuation means being receivable within an opening in the cam means, the improvement comprising, said actuation means including pin means which is mounted with clearance within a cylindrical member, securing means for securing said pin means with respect to said cylindrical member, and said pin means being self-centered relative to said cylindrical member as said pin means is secured by said securing means.