It was difficult and complex to choice the design parameters of the non-backlash double-roller enveloping hourglass worm for the acquisition of the best engagement performance. Aiming at this question, the formulas of contacting parameters which included induced normal curvature, lubrication angle, rotation angle and relatively entrainment velocity were derived. A new multi-object parameter optimazition method was presented using the formula of Dosen to create the optimization equation based on the rotation angle and relatively entrainment velocity. Based on its characters, the equation was solved using the genetic algorithm .The result of analysis proved that the method was effective and possible and the parameters can acquire the best engagement performance. The problem of choice the parameters was solved through the studies which provided a new method to choice the best parameters for design and manufacture the non-backlash double-roller enveloping hourglass worm.
