The Analysis And Design Of Harmonic Gear Drives

Harmonic gear drive, a compact mechanical device producing high mechanical advantage and speed reduction, has been used to accurately position the arms and wrists of robots. This device, operating on the principle of nonrigid body mechanicsr has been found to have positioning errors. Such errors, inherent in the drive, adversely affect the performance. In this paper, a kinematic model is developed to analyze the positioning errors. Error curves, based on most common harmonic gear drive geometry, are presented. Design guidelines are also provided for the minimization of positioning errors. It is hoped that the results would be useful for the rational design of harmonic gear drives.