TOOL FOR MANUFACTURING CROWN WHEELS

摘要

PCT No. PCT/NL94/00028 Sec. 371 Date Jun. 7, 1995 Sec. 102(e) Date Jun. 7, 1995 PCT Filed Feb. 3, 1994 PCT Pub. No. WO94/17945 PCT Pub. Date Aug. 18, 1994A tool for manufacturing crown wheels by means of a machining hobbing process, which consists of a disc which can rotate about its axis and on the circumference of which machining elements are disposed whose cutting edges lie in the surface of a profile which mainly extends over the circumference of the disc as helical ribs. In each cross-sectional plane perpendicular to the screw direction of the ribs, the profile has the shape of a number of profile teeth situated next to one another. The profile shape is based on the base geometry of a pinion which is characteristic for the crown wheel to be manufactured and has involute toothing. The profile has such a shape that a part thereof lies outside the surface of revolution which is formed by rotation of the addendum circle of the characteristic pinion about the rotational axis of the tool. As a result, the tool has machining elements or machining element parts whose cutting edges lie in the surface of the portion of the profile outside the surface of revolution formed by rotation of the addendum circle and can serve for performing a premachining operation when manufacturing a crown wheel.