Abstract:Based on the functional requirements of variable-cycle engine (VCE) mode switching, a universal design method for a driving and switching mechanism (DSM) is proposed. A universal DSM with a double row planetary gear train (DRPGT) is designed in which the phase and transmission ratio can be adjusted at the same time. A series of mechanism schemes with similar structures and functions are obtained by configuration design and topology analysis, and rough set theory is used to study the classification and type synthesis. Finally, a series DSM scheme with a DRPGT is obtained, with one planet gear in each group in the front row between the gear ring and sun gear and two outer gearing planet gears in each group in the rear row. This kind of scheme not only meets the demands of VCE mode switching, but can also interrupt the power transmission in case of emergency. Research results indicate that, the design analysis method which is applied to the classification and type synthesis of mechanism schemes is efficient and reliable.