Investigation of the Meshing Conditions of a Flat Wheel Harmonic Gear Drive

The function principle of the flat wheel harmonic gear drive is similar to the basic principle of the classical harmonic drives. The flexible and the solid gear of the drive are coaxial flat wheels. The rotating wave generator deforms periodically and elastically different portions of an annular face gear on the flexible member in axial direction into engagement with teeth on an annular face gear on the solid member. The numbers of teeth of the face gears are different. An analytical method is introduced, that investigates meshing conditions of flat-wheel harmonic drives. The numbers of the connected teeth taking part in the load-transmission and the tangential component of the acting force on them in the range of tooth engagement are calculated. It depends on the loading torque, so calculations were launched at different levels of torques in case of various parameters. The tooth flanks were approximated by planes. Results are compared with the results of calculations based on finite element analyses.