Meshing noise from timing chain drives

Abstract

Controlled experiments on a specially constructed timing chain drive test stand have shown that the most significant noise source in roller chain drives is from impacts between the chain links and the sprocket teeth during their meshing process. Despite its importance, a study that can analytically predict and experimentally verify the characteristics of meshing noise has yet to be performed. A method is presented that can quantify the meshing noise as a function of the critical system parameters, such as chain speed, tension, mass and shape of chain links, and sprocket geometry. A comprehensive model that integrates the chain transverse and longitudinal vibrations with the sprocket motion is developed. The approach also couples the local meshing impulse with the global system dynamic response of the vibrating chain. Parametric tests were carried out on a test stand in which a roller chain and up to three sprockets could be tested. Besides the chain speed and tension, the local vibration and the sound pressure levels are recorded. This fundamental investigation provides new insight into roller chain noise problems. [Work supported by General Motors Corp.]