Prediction of alignment deviations on a lead crowned helical gear manufactured by a hob

摘要

A drawback when hobbing lead crowned helical gears is that the gear tooth will be manufactured with alignment errors, often denoted flank twist. Together with other source deviations, these errors must not exceed the predetermined tolerances if the gear is to be finished hobbed. A simulation model is developed where the hobbing process can be analysed without additional errors resulting from real conditions. The result from this simulation model show very good correlation with an experimental gear ground by a hob. An analytical analysis of the manufacturing process results in a novel method to predetermine the minimum alignment deviations on a hobbed gear tooth. When selecting manufacturing methods, the results from this study can be used to determine if a hob can produce the helical gear within given tolerances.