Abstract
Effects of swelling of nylon gear due to moisture absorption on noise and vibration are investigated. Gear swelling causes large negative pressure angle errors on the tooth profiles of nylon gear. Swelling of nylon gear influences the noise generation, however the effects appear limitative. Namely swelling of nylon gear has no very effect on the noise except the case operated under low load condition. In spite of existence of large pressure angle errors on tooth profiles, the body of swelled nylon gear does not vibrate so hard compared with that of non-swelled nylon gear. It is considered that swelling of nylon gear due to moisture absorption increases in the tooth compliance and increases in the acts on relaxation the dynamic mesh force.
