A Dynamic Model of a Planetary Gear Set in Turbofan Engines

Development of advanced geared turbofan engines requires improving methods of design and strength analysis of power gears of the planetary mechanisms. The authors propose a hybrid dynamic model of a planetary gear set for a turbofan engine that allows estimating dynamic loads in the meshed gears and on the supports of the reduction gear in the whole range of rotational speeds. The finite element method is used in this model to obtain functional relations of composite deviations, variable stiffness of meshing and distribution of the full bending and contact stresses in the meshed teeth. The effect of stiffness of the sun gear supports and the ratio between the satellite mesh phases on the dynamic stresses in the system is analyzed. The proposed dynamic model is used to develop recommendations on reducing dynamic loads in planetary gear sets of turbofan engines.

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