Worm hob for machining toothed wheel or crown of e.g. mining exploration tunnel boring machine, has insert holders positioned axially with respect to corresponding axial abutment surfaces that are formed by annular grooves in hub

摘要

The hob has a hub (20) including axial abutment surfaces (24) that are formed by annular grooves (22) and axially offset from one another. Each axial abutment surface is formed in the form of a revolution surface portion revolving about an axis (98) of the hub. Insert holders (60) are removably fixed around the hub to form a propeller or rings axially offset from one another. Each insert holder includes housings (68) to receive cutting inserts (66). Each insert holder is positioned axially with respect to one of the axial abutment surfaces of the hub.