New Method of Manufacturing Curved Tooth Trace Cylindrical Gears using a CNC Hobbing Machine

This paper proposes a new tooth cutting method for cylindrical gears using a CNC hobbing machine. By introducing an attachment, a flying tool (male or female cutter) can be rotated around an axis perpendicular to the hob spindle of the CNC hobbing machine. By rationally controlling the revolution and tangential feed of the flying tool, a special cylindrical gear with a curved tooth trace is generated. The tooth cutting process is continuous, resulting in highly effcient gear cutting. We measured the tooth Profiles and Performed tooth bearing tests on the manufactured gears. In addition, an analytical method for describing the tooth profile and tooth trace is presented. Based on the calculated results, the tooth trace of the resultant gear is a curve that forms an approximately circular arc. Furthermore, the tooth profile, which lies on a plane perpendicular to the axis of the gear, almost coincides with an involute curve, the pressure angles of which change nonlinearly along tooth trace.