A Study of Relief Grinding Method for Screw Rotor Hob with Pencil Type Wheel. 1st Report. Profile Design Method of Pencil Type Grinding Wheel.

Abstract

A precise analysis has been made for a design method in order to obtain the profile of a pencil type relief grinding wheel for a hob which cuts a given screw rotor surface, especially in the case in which the cutting edge profile of the hob is given as a series of dispersive points. Firstly, it is clarified that under certain circumstances a singular point (a cusp) will occur on the profile of the relief grinding wheel corresponding to the cutting edge profile of the hob, and that, because of the cusp, the interference phenomenon will occur on the profile of the relief grinding wheel. Secondly, numerical analyses for the following two purposes arc proposed. One is to determine the interference by using a conditional equation of the cusps. And the other, which is more important is to obtain the profile of the relief grinding wheel. Then, these theoretical analyses are verified by applying them to the dimensions of screw rotor hobs.