PITCH-ERROR MEASURING METHOD OF SPHERICAL HOB

摘要

PURPOSE:To make it possible to measure the pitch errors of a spherical hob at a low cost, by measuring the positions of a cutting blade on a working line associated with the actual a gear generating. CONSTITUTION:In generating a gear by a spherical hob 1, the projected locus of each hob blade 3 of the spherical hob 1 acts so that an imaginary gear is rotated at an equal speed. The working movement is shown by broken lines. The most important parts, which are associated with the gear generating, in each hob blade 3 are intersections (a)-(j) of the cutting blade of each hob 3 and a working line B. The positions of the intersections (a)-(j) are measured and compared with geometrically determined theoretical values. Thus overall accuracy as a tool can be judged, and the theoretical accuracy of a gear to be cut can be ensured.