Influence of tool eccentricity on surface roughness in gear skiving

Gear skiving is a state-of-the-art technique for machining internal gears with high efficiency. Numerical simulation method being able to analyze the eccentricity error e of cutter is critical to the understanding on the formation of surface roughness in skiving process. In this work, we proposed a novel Z-map-based numerical model to calculate the surface of gear flanks with eccentricity errors up to 9 μm. Correlation between eccentricity error and gear flank profile was clarified by numerical simulation and supported by experimental verification. The results show that the eccentricity error imposed a low-frequency motion during the generation of scallop height, leading to a surface roughness with a maximal error about four times that of the theoretical roughness. The e-induced scallop height became the majority factor account for variation of surface roughness when e exceeds 1.4 and 2.3 μm for feed rates of 0.4 and 0.8 mm/rev, respectively. The experimental result further supported the capability of proposed simulation model in providing detail surface features of gear flanks in skiving process.