Abstract: Aiming at the disadvantage of current internal gear manufacturing method, a continuous generating method for internal gear with crown worm cutter is presented. Based on the theories of differential geometry and gear mesh, the secondary action principle of crown worm driving and the mathematical model of crown worm cutter are established. The necessity for the reproduction of internal involute generating surface and the conjugate relationship of internal gear processing are also analyzed. The tooth profile of the crown worm cutter is studied, namely to analyze the law of the parameters on tooth undercutting, and the approach to avoid the tooth undercutting is provided. The rough processing parameter optimization methodology and precise processing principle are analyzed based on the principle of virtual center distance. The studies supply an effective and precise approach to process internal gears.

Key words: Crown worm cutter, Crown worm driving, Internal gear grinding, Internal gear hobbing