Effect of Geometrical Parameters on Harmonic Drive Efficiency

One of the requirements imposed on harmonic drive, is to increase its efficiency. Reducing losses requires a mathematical model of a harmonic drive that should be used for selection of the main options of a gear with account of friction losses. The main losses in harmonic drive with cam wave generator are the rolling friction loss in a flexible bearing and sliding friction loss of teeth in a gear. The developed mathematical model allows to carry out the power calculation gear and to determine its efficiency. The proposed model takes into account the spatial nature of the deformation and interaction of gear components. Conducted computational studies have shown that the efficiency of harmonic drive transmission is affected by value of the resistance moment; the coefficients shift gears; the radial deformation of the flex spline; and the gear ratio. Obtained relationships broaden knowledge about the effect of harmonic drive parameters on its efficiency.