关键词: 航空发动机, 低压转子, 套齿连接结构, 刚度特性

Abstract: Focusing on aero-engine low-pressure rotor spline couplings, the nonlinear characteristics of bending stiffness and the mechanism were analyzed, a solid finite element model of spline coupling considering gear surface contacts was established, the static stiffness experiments of the spline couplings were carried out. Through simulation and experiments, the nonlinear variation law of the structural stiffness of spline couplings was studied, and then the influence laws of fit clearance, tightening moment and torque on bending stiffness were discussed. The research results show that, due to the different contact states and stress conditions of the positioning surfaces, the bending stiffness variations of the spline couplings were mainly divided into two stages, which had piecewise nonlinear characteristics. The bending stiffness of the spline couplings is sensitive to the fit clearances of the positioning surfaces, and reducing the fit clearances of the positioning surfaces may effectively improve the bending stiffness of the structures; tightening moment has little influence on the bending stiffness, and under low load conditions, torque has an obvious effect on the bending stiffness. 

Key words: aero-engine, low pressure rotor, spline coupling, stiffness characteristics