Measuring the effects of faults for the rotational characteristics of small plastic gears

Abstract The measurement of the recirculation torque on the input side of the gearbox is a commonly used method for gear drives. This can also be suitable for detecting the effects of periodically occurring faults on small plastic gears, for example the faults of the tooth thickness or pitch. In this article, we investigate the tooth thickness faults of small plastic gears manufactured with an SLA 3D printer. In our work, we first determine the fluctuation of chordal tooth thickness by microscopic examination. Then, using a special device, we measure the same fluctuation in the recirculation torque curve. In addition, we also examine some cases where the tooth thickness is decreased or increased with a great extent.