| Although roller chain drives are widely used today in various high speed, high load power transmission applications, their dynamic behavior is not well understood. Current chain design procedures rely on experimentally derived charts relating speed and number of sprocket teeth to a maximum permissible horsepower. They do not predict the chain displacements, load distribution, or stresses and only apply to a standardized chain geometry and one particular chain material. For applications which fall outside these guidelines, experience and testing are really the only resources available with which to determine the feasibility of the design. Analytical techniques for the accurate, quantitative dynamic analysis of roller chain drives are very limited in their scope, primarily because the highly complex dynamic behavior of the chain severely restricts an analytical treatment.;As a first step towards the rational, predictive design and analysis of roller chain drives, a generally applicable, computer-aided procedure has been developed for the dynamic analysis of these systems. Lagrange's equations of motion are derived by assuming the roller chain to behave as a series of masses lumped at the roller centers, connected together by massless bars of constant axial stiffness and the equations are solved in the time domain. This approach addresses important factors of chain dynamic behavior such as impact, discontinuities in span length, coupling between longitudinal and transverse motion, as well as coupling between motion and boundary conditions. The output of the program consists of displacement, velocity, and tension for any point in the span as a function of time as well as the sprocket angular motion. It can be used in the analysis of existing drives, or in the design of new drives.;This procedure has been used to study various chain configurations and the detailed results of these investigations are presented here. Although it is difficult to make generalizations due to the nonlinear nature of the problem, the results do show good agreement with experimental observations and indicate some general trends, helping to provide additional insight into the dynamic behavior of these systems. |
