Kinematic Synthesis of One-DOF Geared Mechanisms According to Specified Gain Types

Although the atlas of the geared kinematic chains (GKCs) had been enumerated decades ago, few studies had focused on how these synthesized GKCs can be applied according to the kinematic requirements of geared mechanisms in practice. In this paper, the kinematic behaviors of one-DOF, single-output geared mechanisms of up to six links are analyzed based on the concept of kinematic fractionation and the formulas of global gains are established. Classification of the geared mechanisms is obtained according to the gain types, ordinary, subtractive, fractional and composite. A set of rules for the assignment of ground, input and output links of single-KU and multiple-KU geared mechanisms without redundant links are proposed according to gain types. As a result, the kinematic synthesis of the one-DOF, single-output geared mechanisms of up to six links according to their associated gain types can be easily accomplished. An exemplary design of a geared mechanism with subtractive gain type is provided for the illustration of the proposed methodology.Copyright © 2008 by ASME