This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry.

Roller chains are commonly used to transmit mechanical power in many kinds of machineries for wide industrial fields. Roller chain manufactures are doing a lot of efforts to improve the wear resistance through conventional real chain type wear testing with huge amount of time and cost. In this study, a new wear testing machine is developed to evaluate wear amounts more efficiently without using main chain components such as inner plate, outer plate and roller. The results show that the nearly same amounts of wear rate and wear status can be obtained between the newly developed wear testing machine and the conventional machine. It may be concluded that the newly developed wear testing has sufficient reproducibility and can be used more conveniently for investing roller chains compared to the conventional wear testing machine.

Roller chains are commonly used for transmission of mechanical power on many kinds industrial machinery. Roller chain makers have done a lot of efforts to improve the wear resistance by using conventional types of wear testing machine. However, such conventional wear testing needs huge amount of time and cost. Therefore, this study focuses on developing a new wear testing machine, which can evaluate the wear amount efficiently without using main chain components such as inner plate, outer plate and roller. The experimental results show that this newly developed wear testing machine may realize the almost same wear rate under stable condition and similar wear status of the conventional chain type testing machine. The newly developed wear testing machine may be useful for improving the wear resistance of roller chains conveniently compared to the conventional chain type testing machine.