Hob for worm gear manufacturing with circular profile

Abstract

A method is developed for the design and manufacturing of the hob for processing a worm gear with circular axial profile. The calculation includes the determination of the generator surface and the cutting edge profile of the hob, the profile of the conical, dished, and pencil-type grinding wheel for relief grinding the hob teeth, the optimal values of setting angles of the grinding wheel axis to improve the precision of the resharpened hob, and the determination of deviations of the cutting edge of the resharpened hob from the required profile. The corresponding computer program is developed. By using this program the influence of the lead angle of the hob and the diameter of the dished grinding wheel for hob tooth relief grinding on the optimal values of setting angles is investigated. The obtained results show that by using the optimal machine setting, the precision of the resharpened hob is considerably improved. © 1993.