Abstract
In this study, we investigated the properties of noise and vibration for a pair of gears engaged a nylon gear with a steel gear. On the basis of experimental results, we considered about the noise generation mechanism. It becomes clear as follows. The plastic gear is excited vibration heavily and the noise is radiated loudly from the plastic gear rather than the mating steel gear. The vibration of plastic gear is caused by the flexibleness of plastic gear tooth and the lateral vibration of plastic gear influences the noise radiation directly. It is considered that one of the practical ways to reduce the noise of plastic gear is to reduce the noise radiation from the plastic gears by decrease in lateral vibration.
