Abstract
In the last few years, metallic gears have been replaced by polymer gears in various applications, mainly in low and moderate loading conditions. They have lower inertia, less weight and run much quieter than their metal counterparts. These characteristics are further enhanced in case of polymer composite-based gears. In the present work, the transmission efficiency of glass fiber-reinforced homogeneous polyamide 66 (PA66) composite gears and functionally graded material (FGM)-based PA66 gears has been investigated. Homogeneous gears are fabricated by conventional technique, whereas FGM-based PA66 gears are fabricated using a novel manufacturing system. Unfilled PA66 gears are also fabricated by horizontal centrifugal casting technique using injection molding machine for comparative study. PA66 pellets reinforced with 15 and 30 wt% glass fibers are used to fabricate homogeneous as well as FGM gears. Experimental work is performed on a polymer gear test rig. Experiments are performed at various speed and torque combinations for 0.2 million cycles. Results show that the operating torque has more impact on the transmission efficiency of the fabricated gears as compared to rotational speed.