Tooth Deviations of an Involute Helical Gear Manufactured in a Simulated Hobbing Process with Introduced Errors

External involute helical gears are usually manufactured through hobbing, commonly with a subsequent grinding or skiving operation. One way towards the industrial pursuit of more competitive and sustainable manufacturing is to reduce the number of processes, while retaining functionality and quality. In the hobbing of gears, the manufacturing errors are most often connected to the tool and/or the fixture. These errors need to be kept within tight tolerances to achieve sufficient quality of a finished hobbed gear. It would therefore be of great interest to be able to predetermine the quality of a finished hobbed gear, based on tolerances of the manufacturing process. Thereby the motivation is to analyze the impact of these errors, on the tooth surface of a hobbed gear. In this paper the manufacturing process is simulated, using an analytical geometric mathematical model, to determine the geometry of the hobbed gear tooth flank in three dimensions. Various errors, linked to the manufacturing process, are introduced in the software implementation of the mathematical model. An experimental study was performed, with errors of same type and magnitude, to validate the simulation results. The simulation model allows determining the geometry and the quality of the gear tooth, prior to manufacturing, at any section over both profile and helix.