machine tool to create a epitrochoiden or similar gekruemmten area of werkstuecks

摘要

Apparatus for generating complex curved surfaces such as the epitrochoidal bores of rotary combustion engines, e.g., "Wankel" engines. A workpiece is, in effect, fixed to a first imaginary cylinder which is rolled about the inner circumference of a larger second cylinder. A cylindrical cutting tool is positioned to contact the workpiece along a predetermined machining line which is parallel to the axes of the two imaginary cylinders, the machining line also being fixed relative to the larger of the two cylinders and outside of its outer circumference. The relative movement of the tool and workpiece causes the machining line to generate an eiptrochoidal surface on the workpiece, and this generated surface is maintained theroretically exact by maintaining the axis for the cylindrical cutting surface of the tool in a plane passing through the machining line and through the line of instantaneous tangency between the two imaginary cylinders as the smaller cylinder rolls relatively about the inner circumference of the larger cylinder. This combination of complex relative movements is provided by a relatively simple machine format which includes a drive mechanism utilizing three separately driven rotating gear members. The two members which simulate the rotation of the "imaginary" generating gears are concentrically mounted and do not intermesh or otherwise run relatively around the circumferences of each other, and all three drive gears rotate about axes which remain substantially fixed relative to each other at all times during machine operation.