Wear Performance of Commercial Polyoxymethylene Copolymer and Homopolymer Injection Moulded Gears

Polymer gears are an effective solution to lightweighting, which are highly demanded in the automotive industry. Acetal is one of the most widely used polymer gear materials. In this study, two commercial grades of acetal, homopolymer (POM-H) based and copolymer (POM-C) based, were injection moulded into gears with their wear performance compared. Noticeable differences were discovered in failure mechanism, and thermal and mechanical characteristics, which led to a difference in performance prediction. The service life of over two million cycles was expected under a torque up to 10 N m, with POM-H gears having 35% better service life than POM-C. The differences in the properties of POM-H and POM-C should be considered in future industrial applications such as the replacement for metal gears.