On the embedded kinematic fractionation of epicyclic gear trains

In this paper, the concept of kinematic fractionation is introduced for epicyclic gear trains (EGTs) which contains structural fractionation as a degenerate case. Kinematic fractionation provides a viewpoint to determine the type of fractionation of an EGT by distinguishing the independent transmission path(s) inside. With the concept of kinematic fractionation, kinematically independent group(s) embedded in an EGT can be identified. A composition list, which depicts the links and the link connection in the associated group, is used to determine the type of fractionation. It is found that most previously enumerated structurally non-fractionated EGTs in the literature are kinematically fractionated. It is shown that a structurally hon-fractionated EGT may be kinematically fractionated while a structurally fractionated EGT must be kinematically fractionated. The concept of kinematic fractionation can lead to efficient topological analysis of EGTs with physical comprehension. Copyright © 1999 by ASME.