Nonlinear Forced Vibration of Roller Chain

Abstract

As a roller chain possesses a high modulus of elasticity for elongation and its mean line density is comparatively large, the influences of the weight of the chain and of the fluctuation or tension during vibration on the frequency and the mode of natural vibration are remarkable. Hence the linear theory seems hardly to be valid. In this report, the forced vibration of the chain spanning vertically with boundary conditions where it is fixed at the one end while subjected to a harmonic forced displacement at the other end is investigated. It is shown that the properties of nonlinear forced oscillations reveal a typical hard spring type and vary with a shape parameter K of the link, a total link number N, a parameter p constructed of the ratio of (total weight of a chain /2) to tension T_m and a parameter λ composed of the amplitude of forced displacement A, modulus of elasticity E_d, tension T_m and total length l. The theoretical and the experimental results are compared. In order to estimate the influence of the friction in the bush parts, miniature bearings were inserted in these parts to remove friction.