Theoretical Research on Load Capacity of Double-Roller Enveloping End Face Engagement Worm Gear

ABSTRACT

The calculation of load capacity is the key problem of worm's analysis. Taking the double-roller enveloping end face engagement worm gear as an example, a method for the numerical analysis of capacity was proposed based on finite element theory and fatigue analysis. Based on the meshing theory, the meshing equation was derived, and the accurate mathematical model for tooth surface of worm gear was established. Then the finite element modeling of worm gear was to analyze the contact stress and stress-strain effect. Finally, applying the safe life calculation method, the factors of fatigue life of worm gear were analyzed and researched. The researched result indicate that the worm gear has a quite good mesh performance when the worm meshing teeth have eight pairs. Under the same condition, with the analysis of the model's strength and finite elements performed, it was confirmed that the load capacity of end face engagement worm gear has an obvious improvement by comparison of that of enveloping hourglass worm gear, further, the maximum tooth root stress was only 6.5% of enveloping hourglass worm'. Meanwhile, the load distribution is in a declining invert L shape. And the fatigue life of end face engagement of worm gear pair could be attained 10⁷ cycles. Therefore, this study results provided the theoretical basis and industrial applications value for transient analysis of end face engagement of worm gear and manufacturing constantly in the future.

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