Analysis of structural design defects in parallel overloading mechanisms with cam transmission mechanism

Abstract

In this paper, the design defects of the cam transmission mechanism is produced by defects in the geometric characteristics, such as curvature interference of contact surface and unreasonable pressure angle, which greatly affect the dynamic behaviors. In order to avoid the shortcomings of traditional design methods, surface family envelope theory is used to fit the profile curve of the cam curve groove. Through analyzing the defect characteristics(curvature interference and unreasonable pressure angle) of the cam curve groove, the self-contained defect identification algorithms are proposed. To systematically identify whether the cam curve groove has design defects, a complete algorithm based on the self-contained defect identification algorithms is designed. Finally, the feasibility of the identification algorithm is validated by numerical examples. The numerical examples are validated by the finite element method and computerized numerical control machining. The results reveal that curvature interference is generally not produced if the appropriate processing method is adopted, and the design of the component size directly determines whether the pressure angle defect occurs. Compared with fault diagnosis of cam mechanism, the proposed self-contained algorithms show simpler calculations and higher accuracy, and it can also properly analyze the effect of design parameters on the dynamic behavior of cam transmission mechanism.