Rahim Isnan Al Hilman
LDS Team 2011

ABSTRACT

Spatial four bar linkage mechanisms are applicable to transmit the rotation on unparallel axes. One of their configurations is RSSR mechanism which is composed of Revolute-Spherical-Spherical-Revolut joints. In the dimensional synthesis of the mechanism many considerations must be maintained carefully related to the number of kinematic constants which must be determined and limitations of workingspace of the spherical joint. In this research, the dimensional  synthesis was carried out based on available workingspace of spherical joint and transmission angle. It was used the generating function to determine the kinematic constants of the mechanism to perform specified relationship between input crank and follower displacements.
For the case study, it was synthesized the RSSR mechanism with revolute and follower axis orientation perpendicular to each other. Design specifications for the mechanism are crank angle, θ is 0^o-360^o (fully cycled) and rotation angle of follower, φ is 0^o ≤ φ ≤ 180°. Based on the synthesis results, it was obtained the set of kinematic constants of the mechanism as follow, lengths of crank, coupler and follower  are 5.55, 8.07and 2.79 unit respectivelly. The obtained mechanism can perform fully rotate of crank, 0o ≤ φ ≤ 133^o  range motion of the follower and  38.4° ≤ α ≤ 101.6^o range of the transmission angle.

Keyword : Dimensional synthesis, function generator, RSSR mechanism, transmission angle