Method for using a variable-tooth-thickness worm-type tool to fabricate gears with longitudinal crowning

A method for fabricating a gear blank into a gear with a variable-tooth-thickness worm-type tool used to fabricate a gear blank into a gear, said variable-tooth-thickness worm-type tool comprising a main body and at least one spiral blade distributed on said main body and featuring variable tooth thickness, comprising steps:

• describing said main body with a rack cutter coordinate system;
• describing said spiral blade distributed on said main body with a tool coordinate system;
• transforming vector parameters based on said rack cutter coordinate system into vector parameters based on said tool coordinate system so as to simulate said main body with a rack cutter, and developing said spiral blade to have variable tooth thickness;
• and
• according to a structural characteristic of variable-thickness teeth of said spiral blade, setting feeding amounts of a longitudinal feeding degree-of-freedom, a tangential feeding degree-of-freedom, and an inclined angle degree-of-freedom and neglecting a radial feeding degree-of-freedom for crowning said gear blank and inhibiting twists of tooth flanks of said gear blank.