Gear hobbing tool as well as an insert holder, a chip removal unit, and an insert kit therefor

An insert holder for gear hobbing tools, comprising:

• an upper part;
• a bottom part, the upper part having a seat for the receipt of milling inserts and delimited by an axial support and a tangential support, wherein the seat is placed between two shoulders included in the upper part, a first shoulder including the tangential support;
• and
• a wedge having a through hole that extends between an upper side and an underside of the same and accommodates a screw having a male thread that is tightenable in a threaded hole in the holder, and having a key grip that is directed upward from the upper side of the wedge, the wedge including two opposite contact surfaces, which converge toward the underside of the wedge, one of the contact surfaces facing the tangential support surface and the other contact surface facing the second shoulder.

An insert kit for a gear hobbing tool the gear hobbing tool having a head having a front side, a back side, and a center axis on which the head is rotatable and a plurality of chip removal units detachably mounted along the front side of the head, each chip removal unit including an insert holder having an upper part and a bottom part anchored in the head, the insert kit comprising:

• a plurality of milling inserts, each individual milling insert being fixed in a seat located in the upper part of the insert holder by a screw and delimited by an axial support and a tangential support, the screw having a male thread and a key grip at one end, wherein the seat of each individual insert holder is placed between two shoulders included in the upper part and protruding in the direction from the front side of the head of the gear hobbing tool, a first shoulder including the tangential support, each individual milling insert being arranged between the tangential support and a wedge having a through hole that extends between an upper side and an underside of the same and accommodates the screw, the male thread thereof being tightened in a threaded hole in the insert holder, and the key grip facing upward in relation to the wedge, the wedge including two opposite contact surfaces, which converge toward the underside of the wedge, and one of which is facing the milling insert and the other facing the second shoulder, each individual milling insert including a center plane, an upper side having a chip surface, an underside, and a clearance surface, which, together with the chip surface, forms a cutting edge that includes two part edges, a front nose edge and a flank edge running backward from the same and deviating from the center plane wherein two types of milling inserts have an asymmetrical shape such that a clearance partial surface adjacent to the flank edge of the individual milling insert has a greater clearance angle than an opposite side surface, the flank edge of a first type of milling insert being placed to the left of the center plane, while the flank edge of the second type of milling insert being placed to the right of the center plane.