A Study on Noise and Wear of Injection Molded Plastic Gears With Deformed Layer

Abstract

The injection molded plastic gears are widely used for rotation and power transmission for the reason of the low noise and the low cost. The deformed layer such as the skin layer appears easily in the tooth surface of the polyacetal gear. Therefore, authors studied the deformed layer actively applied in the two types of the low noise plastic gears. This paper describes the analysis and power examination of the polyacetal gears manufactured under the different molding conditions. The conclusion obtained are as following: (1) The temperatures difference of melted resin and the mold influences the hardness and the skin layer thickness of tooth. (2) The noise level becomes so low that the deformed layer produced for the gear’s tooth is thick. (3) The abrasive wear of gear is affected by the deformed layer, and the life of gear can be considered the moment when a noise level rose abnormally.