Numerical Wear Analysis of a PLA-Made Spur Gear Pair as a Function of Friction Coefficient and Temperature

Abstract

Polylactic acid (PLA)-made machine elements exhibit easy machining, biodegradability, and excellent mechanical properties. However, enhancing their wear resistance is still a crucial engineering point, which may be achieved by altering (lowering) their coefficient of friction (CoF). Therefore, the first aim of this paper is to analyze how wear is affected by the alteration of CoF. The second aim is connected to the fact that PLA is sensitive to heat, which also limits its applicability. Accordingly, the next goal is to explore the effect of temperature on wear propagation. This study answers these questions by means of multibody dynamics simulations of a PLA-made spur gear pair. Simulations were carried out under constant torque, while the CoF and the temperature were varied in a normal operation domain (CoF: 0.1–0.05, T = 20–30 °C). The results showed that the wear volume gradually began to decline at approximately 0.085 CoF, whilst convergence to steady-state wear could be observed at 0.05 CoF. In conclusion, alteration of the CoF can lower wear by 35%, in this specific domain, while even a 5 °C rise in temperature causes 40% wear progression. The feasibility of the numerical procedure was validated by comparing numerically and experimentally obtained wear–torque results.

Wear Analysis of 3D-Printed Spur and Herringbone Gears Used in Automated Retail Kiosks Based on Computer Vision and Statistical Methods

“…The friction coefficients measured at various temperatures for operating PLA gears were studied by Feteke, who confirmed significant wear reduction (by 35%), achievable by an adequate temperature-related improvement of the mentioned coefficient. As found, as high as a 40% progression of wear may result from a 5 °C temperature increase [ 36 ]. Lastly, Tunalioglu et al conducted wear tests on PLA gears undergoing operational conditions [ 37 ].…”

Wear and Service Life of 3-D Printed Polymeric Gears

“…Researchers have examined the strength of plastic gears produced in three-dimensional printers [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. The mechanical properties of gears produced with the 3D printer technique have been studied theoretically and experimentally under different operating conditions [ 34 , 35 ].…”

“…In the comparison of all three polymeric gears, they stated that the most durable gear was the Nylon gear. Feteke [ 43 ] investigated the friction coefficients of PLA gears at different temperatures. As a result, he said, replacing the CoF can reduce wear by 35% in this specific area, while even a 5 °C increase in temperature results in 40% wear progression.…”

Wear prediction considering dynamic load for spur gear in mixed elastohydrodynamic lubrication

“…30 The effects of friction coefficient and temperature on the wear resistance of PLA (Polylactic acid) spur gear were investigated. 31 But the effects of dynamic load on gear wear are out of consideration. The interaction between the surface wear and dynamic behaviour was studied.…”