The invention relates to a harmonic drive which can be manufactured from a small number of plastic injection moulded parts, dispensing with the additional space required for a sensor disk which is flange-mounted on the main drive pinion in order to detect kinematic information for a control circuit, by integrating the corresponding sensor equipment directly into the drive. Preferably, the rotating drive ring is fitted with at least one magnetic dipole as a sensor transmitter whereby the movement thereof when it passes a fixed position on the housing is detected by a stationary detector which is preferably embodied in the form of a Hall generator and mounted on the support ring of the drive.