Additive Manufacturing of a set of Herringbone Gears Assembly

Herringbone gears are frequently used in power transmission systems due to their ability to reduce axial thrust and provide smooth, quiet operation. However, producing them conventionally is costly and challenging due of their intricate double-helical structure. This work investigates the feasibility of fabricating polymeric herringbone gears for low-load applications, such as external gear pumps, by additive manufacturing (AM). We utilized SolidWorks for parametric modeling, Simplify3D for toolpath planning, and fused filament fabrication (FFF) for part production. Two identical herringbone gears, two shafts, and a supporting bracket were fabricated and assembled to create a functional prototype. The initial prototypes including fine teeth and dual-shaft hubs proved ineffective due to excessive support requirements and insufficient strength. A novel design featuring fewer, thicker teeth and a streamlined hub shape significantly enhanced printing and mechanical performance. The findings indicate that FFF is applicable for the fabrication of functioning polymeric herringbone gears for demonstration-scale purposes. Nonetheless, they also indicate that there are issues with feature resolution, build duration, and mechanical integrity. Selective laser sintering (SLS) with nylon has been identified as a superior technique for fabricating geometrically complex and mechanically robust herringbone gears. These results underscore the significance of additive manufacturing in the fabrication of intricate gear geometries and highlight critical design and process considerations for polymer-based power transmission components.