Performance of polymer composite gears - Effect of tooth deflection

Unreinforced nylon 6/6, 20 % short glass fiber reinforced nylon 6/6 and 20 % short carbon fiber reinforced nylon 6/6 materials were used for understanding the effect of tooth deflection on gear performance. Test materials were injection molded into spur gears of 2 mm module, 20° pressure angle, 17 number of teeth and 6 mm face width. A test rig is designed and developed in the laboratory to quantify the hysteresis loss of test gear with the measurement of single tooth deflection during static loading and unloading. The performance test is conducted using a power absorption type gear test rig at a constant rotational speed of 1000 rpm and at 0.8 and 1.5 Nm torque conditions. Temperature of test gears during performance tests is continuously measured using non-contact infrared temperature sensors. The net surface temperature measured in reinforced gear during testing is less than that measured in unreinforced gears. A better heat dissipation and less amount of heat generation contributes to improved gear performance.