The Twinworm Drive—A Self-Locking Worm-Gear Transmission of High Efficiency

Abstract

Up to the present, it has always been accepted as a proven and well-established fact that worm gears or screw threads that are self-locking are bound to have an efficiency of less than 50 per cent. An entirely different type of worm transmission has been developed which is self-locking, yet has a theoretical efficiency that can almost reach 100 per cent. Efficiencies of 90 per cent and above can easily be obtained in practice, and have, in fact, been obtained in models built by the authors. In addition, this new transmission exhibits a number of other unique and useful properties. The paper describes the transmission and develops the theory upon which its operation is based. Design equations are derived for different operating conditions, and a number of possible uses and applications are discussed.