Parametric analysis of tooth surface characteristics of flexspline in harmonic reducer after hobbing

The accurate prediction of tooth surface morphology for the flexspline in harmonic reducers after hobbing is a crucial technology for achieving high-precision harmonic gearing. This study investigates the impact of process parameters on the tooth surface characteristics of the flexspline. Two models were established to study the formation of tooth surfaces using both continuous cutting with a hypothetical rack tool and interrupted cutting with a multi-cutting-edge hob. The resulting surface geometry of the models was compared, and the effect of hob axial feed, hob mounting angle deviation, and hob outer diameter size on tooth surface morphology was analyzed. The study findings indicate that the crowning of gear teeth results in overcutting on the flexspline tooth surface, which is directly proportional to the degree of crowning and hob outer diameter. Furthermore, a lower axial feed speed during the hobbing process reduces material residue, and hob mounting angle deviations can lead to overcutting on one end of the tooth surface and material residue on the other end.