Abstract: A new type worm drive with part of toroid surface of ring with circular cross section is dealt with this paper.
A set of formula of twice enveloping has been derived.
The contact lines. The first and second kind boundary lines. The reclative normal curvature. The angles between the contact lines, relative velocity vetors and tooth axical profiles in various parameter conditions have been calculated by means of computers. The systemalic analysis of that mentioned above is given. We concluded that this new type of worm gears with small ratio has much merit than that with big ratio.
After primary analysis of the different parameters. We have pointed the practical value and application ranges of this worm gears. moreover, the simplization and generalization in calculate have been paid more attention to.