Functional design of power-split CVTs: An uncoupled hierarchical optimized model

This paper provides a new model for the preliminary design of compound power-split CVTs. Unlike the existing models, the presented method allows the engineers to prioritize functionality and efficiency of the transmission, while delaying the choice of the involved gear sets’ layout as long as possible. The design approach follows a specific priority order, and each step deals with one particular issue, without mutual interference. A smart design-chart eases the assessment and the comparison of the only eligible alternatives, and eventually leads to a final feasible constructive scheme, which can be an excellent concept for further optimization and implementation. Moreover, the model is general and straightforward: it does not resort to arbitrary or practice dictated choices, it does not require convoluted and laborious numerical procedures, such as large systems of equations, inequalities or iterative computations.