Selection of worm gearing optimal structure for machine rotary table

Abstract

In this paper, the design of the machine rotary table with a kinematic worm gearing is research. A three-dimensional model of the rotary table assembly structure and the stress-strain state of the worm by the finite element method are researched. Optimization of the worm gearing design with a helicoidally worm as a multivariate problem of optimizing the total minimum length of contact lines in a worm engagement is presented. A feature of this article is the search for such a combination of worm gear input parameters that optimize the characteristics of contact lines by the criterion of minimum contact stresses. As a limiting factor for the criterion of contact length, the coefficient of oscillation is taken. The nature of the extremal function of the contact length depending on the values of the variable’s derivative reflecting the influence of the number of worm threads and the gear ratio is investigated. The effect of the shifting coefficient with the optimal search for the maximum contact length within the standard values of the worm diameter coefficient is shown. An algorithm and an analytical form for the development of a more advanced worm gearing with increased efficiency are proposed.

Keywords

• 3d model
• contact stress
• contact line
• worm engagement
• workpiece turning mechanism