Mass Distribution in a Spatial Mechanism to Reduce Shaking Moment

Background/Objectives: The inertial effects exerted on the supporting frame of a spatial mechanism depend upon the distribution of mass of various links for a particular geometry. The main objective of the present work is to provide a suitable mass distribution to reduce shaking forces and shaking moments. Methods/Statistical Analysis: In the present paper a Generalized Slider Crank Mechanism is analyzed. A geometrical model of seven points is used to represent the mass and moment of inertia of each link. The masses at the seven points are chosen in such a way that the masses on positive and negative sides of each of the three co-ordinate axis are equal but different from the masses located on the other two axes. The seventh point mass is taken at the origin. Each of the point masses are taken to vary between 0.01 and 0.99 times the link mass. Findings and Improvements: The decrease in the shaking moment achieved is found to be due to the overall decrease in the position-vectors of the individual point masses from the origin of the fixed co-ordinate system. Slight reduction in the shaking force is also observed. All the seven point masses considered are positive which differs from the earlier model where negative masses are also allowed.