In this research work an extensive review on use of advance materials and performance of polymer gears. Further, literature on polymer gears has been divided into four divisions based on the type of gear material, performance characteristic, modifications, and manufacturing techniques. Materials like polyamide and acetal and their composites are focused due to their huge application quotient. Use of in total six grades that is, PA6, PA66, PA12, PA46, PA618, and PA645 as gear material have been identified. Use of glass and carbon fiber reinforcements in PA gears with varying percentage in a range of 20%–35% and 15%–30%, respectively have been observed. Failure and performance characteristics such as wear, thermal, fatigue, load, transmission, and operational have been illustrated and described in detail. Research studies to improve thermal performance of plastic gears by modifying gear tooth and its profile has also been discussed along with their effects. Application of advance manufacturing technique such as 3D printed additive manufacturing in producing plastic gears is also talked over in this article. This compiled review work aims to assist researchers in selection of plastic gear material and to explore various factors and parameters affecting the failure behavior and performance of plastic gears.

This investigation focuses on the wear resistance and surface morphology of multi-walled carbon nanotube (MWCNT)-filled bio-based epoxy composites. This study examines the impact of different MWCNT concentrations (0 Wt.%, 0.25 Wt.%, 0.50 Wt.%, and 0.75 Wt.%) on the wear properties of these composites. Techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM) were utilized for comprehensive surface characterization. The results demonstrated a direct correlation between the MWCNT content and the wear resistance of the composites, which were corroborated by robust statistical analysis. Furthermore, SEM and AFM observations disclosed incremental enhancements in both wear resistance and surface quality as the MWCNT concentration increased. This research not only augments the understanding of wear mechanisms in bio-based epoxy composites but also aligns with the burgeoning focus on sustainable materials.

The aim of this technical brief is to provide a new viewpoint of friction factor for contact stress calculations of gears. The idea of friction factor has been coined, for the calculation of contact stresses along the tooth contact for different helical gear pairs. Friction factors were developed by evaluating contact stresses with and without friction for different gear pairs. In this paper, three-dimensional (3D) finite element method (FEM) and Lagrange multiplier algorithm have been used to evaluate the contact stresses. Initially, a spur gear finite element (FE) model was validated with the theoretical analysis under frictionless condition, which is based on Hertz's contact theory. Then, similar FE models were constructed for 5 deg, 15 deg, 25 deg, and 35 deg helical gear pairs. The contact stresses of these models were evaluated for different coefficients of friction. These results were employed for the development of friction factor.