Tribological Analysis and Thermal Behavior of Gear Tooth Flanks in Polymer Gears During Dry Operation

Abstract This study presents comprehensive findings on the tribological and thermal behavior of polymer gears under varying loads and operating conditions. Gear tooth wear-rates and thermal contact behavior were investigated for nylon (PA) and acetal (POM) materials, fabricated using machining (MC). Experimental investigations were performed under loads of 6.5 N m, 8.5 N m, and 9.0 N m, while maintaining a consistent rotational velocity of 1500 rpm. The wear-rates and surface temperatures were systematically monitored utilizing a linear variable differential transformer (LVDT) with a precision of 0.1 µm and a high-resolution thermal imaging apparatus. Results revealed that at 9.0 N m, thermal stabilization reduced wear-rates by 15% compared to 8.5 N m, due to the softened material layer acting as an internal lubricant. Conversely, higher wear-rates at 8.5 N m were attributed to localized debris formation and limited thermal softening. Key findings include the identification of the glass transition temperature of PA at approximately 75 °C and its effect on wear behavior. These insights provide a deeper understanding of polymer gear performance, offering guidance for material selection and operational optimization in high-performance applications.