Modeling and analysis of tooth surface roughness for internal gearing power honing gear

This paper describes mathematical modeling of tooth surface roughness of gear finished by internal gearing power honing (IGPII) process. The surface roughness of gear tooth was decomposed into two parts: (1) tooth profile roughness (Ra-h), and (2) tooth longitudinal roughness (Ra-l). Based on the machining mechanism of IGII, the Ra-h and Ra-l models of involute spiral tooth surface were established considering general roughness theory and internal gearing generating movement between the honing wheel and the work-piece. With the proposed model, the Ra-h and Ra-l of tooth surface can be calculated as a distribution from tooth addendum to dedendum. The IGPH and roughness measurement experiments for the automobile transmission gear were carried out to verify the proposed roughness model. The theoretical values of Ra-h and Ra-l have shown close agreement with the experimental ones. The effect of the IGPH process parameters on roughness values and honing paths are discussed based on the proposed model, and proposing a control method for the stable IGPH quality based on the stable honing velocity. The results have shown that the crossed axis angle under 8 degrees is not suitable for the scope of IGPH process.