Comparative Analysis for Low-Mass and Low-Inertia Dynamic Balancing of Mechanisms

Abstract

Dynamic balance is an important feature of high speed mechanisms and robotics that need to minimize vibrations of the base. The main disadvantage of dynamic balancing, however, is that it is accompanied with a considerable increase in mass and inertia. Aiming at low-mass and low-inertia dynamic balancing, in this article the relative importance of the balance parameters of common balancing principles is analyzed and the balancing principles are compared. To do this, the evaluation of a balanced rotatable link is found to be representative for a large group of balanced mechanisms. Therefore, a rotatable link is balanced with duplicate mechanisms (DM), with a countermass (CM) and a separate counter-rotation (SCR), and with a counter-rotary countermass (CRCM). The equations for the total mass and the inertia are derived and compared analytically while the balancing principles are compared numerically. The results show that the DM-balanced link is the best compromise for low mass and low inertia but requires a considerable space. For the CRCM-balanced link and the SCR-balanced link that are more compact, there is a trade-off between mass and inertia for which the CRCM-balanced link is the better of the two.