Studying the Effective Parameters on Teeth Height in Internal Gear Flowforming Process

The flowforming process is a chipless metal forming process that is used to produce precise thin walled tubes. Manufacturing of internal gears using flowforming process is a difficult-to-achieve, but very interesting process in which the gear may be produced without the need for high forming forces and r high tooling cost. In this study, manufacturing of internal gears using flowforming process is studied. The process has been numerically analyzed and simulated. The plastic behavior of the material, and friction conditions were determined using tensile and friction tests, respectively. Several controlled test were performed to evaluate the validity of simulation results. A comparison of simulation and experimental results indicates very good agreement. Once the simulation is verified, the effects of roller diameter, thickness reduction percentage, feed rate and attack angle on tooth height were obtained using design of experiments (DOE) procedure. According to DOE results, attack angle (α), thickness reduction percentage (T), interaction between roller diameter and attack angle (D×α), and interaction between roller diameter and feed rate (D×f) are the most significant parameters affecting the tooth height. The tooth height increases with increasing the roller diameter and thickness reduction, but decreases with increasing the feed rate and attack angle.