The Influence of Tool Tolerances on the Gear Quality of a Gear Manufactured by an Indexable Insert Hob

Advances in gear hobbing are driven to give higher cutting speeds, longer tool life and higher feed rates. Recently, a new type of hob with carbide inserts has been introduced with benefits in all these conditions compared to regrindable high speed steel hobs. However, with this kind of hob, new challenges occur due to positional errors of the cutting edges when mounted on the tool. These errors introduce manufacturing errors on the gear teeth which have to be controlled. In this paper, the tooth quality of a gear manufactured by hobs with different quality classes is analysed using a simulation model in combination with Monte-Carlo methods. A statistical analysis of a commercial hob provides input to the Monte-Carlo model, where the axial and the radial deviations of these inserts are considered. Simulations are performed with different hob quality classes according to DIN 3968. The results from simulation are compared with experimental results of this actual hob at a gear manufacturer. (Less)