Book excerpt: Worm gears are special gears that resemble screws, and can be used to drive other gears. Worm gears, enable two non-touching shafts in a machine to mesh (join) together. This publication, unique in that it combines both theoretical and practical design aspects, including the latest results of research and development, provides detailed treatment of the theory and production of worm drives, as well as the overarching subject of production geometry of helicoidal surfaces. Included are mathematical models for a number of practical applications; a description of dressing equipment required; treatment of inspection and measurement; the use of intelligent systems; worm gearing for power transmission; selection criteria. · Covers theory and practice of the production and use of these common machine elements · Ideal for researchers and engineers dealing with mechanical drives, gears and manufacturing · The first single volume text in this diverse field