Abstract
It is very important for developing an intelligent hobbing machine design that the hob wear, cutting forces and hobbed gear accuracy are estimated in advance. Using the numerical analysis of hobbing mechanism, a new analytical technique is developed to calculate the volume cut with every hob tooth, cutting forces and feed mark patterns. This paper introduces some qualitative estimation by adapting the new analytical method; (1) Hob wears vs. calculated cutting volume (2) Feed marks remaining on the tooth surfaces of hobbed gears vs. the hobbed gear accuracy. Finish hobbing is superior in productivity, such as high-speed cutting, large amount of cutting stock and so on. This method has a merit of omission of shaving and/or grinding process, if the gears can be finished satisfactorily concerning their condition of accuracy and surface roughness. The ability required to finish hobs is to obtain smooth surface and accurate tooth profile of the finished gears demanded from the performance of gears concerned. This paper also introduces the cermet-and the CBN-tipped finishing hobs for medium hardness gears and high hardness ones (case-hardened gears), respectively, which are different from skiving hobs.
