Features of Manufacturing and Calculation of Gears for New Applications (Review)

New applications and modern methods are described for manufacturing gears made of polymer composites using additive (3D printing) and microelectronics technologies (burning and rapid prototyping from photopolymers). The methods of calculation of the load-bearing capacity, wear and durability of polymer and metal-polymer gears (straight and helical spur, bevel) are considered which are based on methodology of composite mechanics and phenomenological model of fatigue wear during sliding friction. The application of analytical solutions for fast parametric analysis of the stress-strain state of gears is shown, as well as the use of their spatial discretization by finite and boundary elements, taking into account the real geometry of engagement. The use of gears in drives of microelectromechanical systems and the specifics of calculations due to the strengthening of adhesive interaction in tooth contact of miniature gears are considered. The features of the deformation of polymer composites, as structurally inhomogeneous and physically nonlinear materials are noted, which should be taken into account when determining the kinematic accuracy of gears. In this regard, the possibilities of a three-level method are discussed for designing gears made of dispersion-filled polymer composites according to the criteria of strength, deformability and wear resistance. The proposed method provides an iterative procedure for optimizing the material composition and gear parameters, each stage of which includes analytical modeling of the dispersion-reinforced composites used (microlevel), computational and experimental verification of micromechanical models on test samples (mesolevel) and numerical analysis of the stress-strain state of gears by finite element method (macrolevel).