An Improvement of the Tooth Profile Accuracy of a Hobbed Gear by Adjusting the Hob Eccentricity

Abstract

Recent studies have shown that the tooth profile errors of hobbed gears were mainly caused by geometrical error and eccentricity of the hob under good cutting conditions. Because manufacturing a highly accurate hob is very difficult and a highly accurate gear may not be obtained, even though a highly accurate hob is used, it is very important to investigate how to improve the actual meshing accuracy of the hob in the cutting process. In general, the meshing error of the edges caused by the hob eccentricity is nearly sinusoidal and the geometrical errors often contain sinusoidal components. On the basis of these facts, this report proposes a method which makes both of the sinusoidal error components cancel each other out in order to obtain an accurately hobbed gear. The test results clearly show the method's effectiveness in improving the tooth profile accuracy of gears.