Design and simulation for a one-degree-of-freedom-based rectangular path generating mechanism using an ellipse

Abstract

Conventional rectangular path generating mechanisms can not avoid structural complexity due to the large number of components and high degree of freedom. Therefore, the authors present a simplified rectangular path generating mechanism using an ellipse. The mechanism not only consists of much fewer components than conventional mechanisms, but also has one degree of freedom. In the design procedure, a reverse kinematic design is implemented, and a theoretical analysis of the displacement, velocity and acceleration is conducted to validate the superiority of this mechanism. In particular, this paper highlights the low acceleration values at the contact points between the ellipse and the frame. This is noteworthy since acceleration is directly correlated with impulsive forces that induce early malfunctions, low stability and wear in devices using such mechanisms. In addition, this paper discusses achieving optimal eccentricity to have the lowest acceleration at the corners. Lastly, a dynamics analysis for two cases–a mechanism with a perfect circle and a mechanism with an ellipse–is carried out using dynamic analysis software to investigate real reaction force at the corners. Conclusively, the novelty of the mechanism using an ellipse is validated through the kinematics and dynamics analyses.