An investigation on the thermal and wear behavior of polymer based spur gears

This study investigates the potential of three different thermoplastic materials viz. Acrylonitrile Butadiene Styrene (ABS), High Density Polyethylene (HDPE) and Polyoxymethylene (POM) to be used in plastic gearing applications. The gears are manufactured by injection molding process. Thermal and wear behavior of these gears are examined at different torque levels of 0.8, 1.2, 1.6 and 2.0 Nm along with different rotational speeds of 600, 800, 1000 and 1200 rpm. Also, steady state analysis of the gears is carried out at a torque of 1.4 Nm and a rotational speed of 900 rpm to measure the reduction in the gear tooth, durability and failure modes occurring in these gears. ABS gear fails due to excessive wear of the teeth whereas HDPE gear failure is caused by the cracking at the root of gear teeth. ABS and HDPE gears complete 0.5 and 1.1 million cycles, respectively before failure whereas POM gear completes 2 million cycles without any sign of failure.