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The authors propose methods of computerized design and analysis of a spiroid worm-gear drive with ground worm based on the following considerations: (1) The theoretical thread surface of the hob is generated by a cone surface. (2) The worm surface is crowned in profile and longitudinal directions in comparison with the hob thread surface. (3) The double crowning of the worm enables to localize the bearing contact and obtain a predesigned parabolic function of transmission errors of an assigned level. Computerized design of the worm-gear drive enables to discover and avoid singularities of the generated worm face-gear surface and pointing of teeth. The meshing and contact of the double-crowned worm and the worm face-gear is simulated to determine the influence of misalignment on the shift of bearing contact and transmission errors. Computer program for numerical solution is developed and applied. A numerical example that illustrates the developed theory is provided.

A computerized investigation of the influence of alignment errors on the transmission errors and the shift of the bearing contact is performed. The investigation is performed for an imaginary hypoid gear drive with conjugate tooth surfaces. The transmission error functions caused by misalignment are shown to be periodic discontinuous almost linear functions with the frequency of the cycle of meshing. The above functions can be totally absorbed by a predesigned parabolic function. The shift of the bearing contact caused by misalignment has been determined as well. The investigation is based on computerized simulation of meshing and contact of gear tooth surfaces. The machine-tool settings for the generation of the designed gear drive have been determined. A numerical example that illustrates the developed theory is given.