复杂转子系统支点动载荷模型及其优化设计

Bearing dynamic load model and optimal design of complex rotor system

针对高推重比涡扇发动机中带中介轴承复杂转子系统的支点动载荷振动响应及优化设计问题,建立了转子系统支点动载荷力学模型,研究在不同转速下,不平衡量、转子弯曲变形及轮盘惯性载荷等因素对支点动载荷的影响。计算分析了双转子系统支点动载荷随转速变化规律,揭示了高速双转子系统中介支点动载荷与转子弯曲变形及轮盘惯性载荷的关系,并提出了基于转子弯曲变形弹性线斜率控制的双转子系统支点振动响应优化设计方法。结果表明,通过优化高压涡轮后轴颈结构、调整低压涡轮后支点靠近中介支点,可以有效减小中介支点动载荷的大小和不平衡量对其影响的敏感度,为具有中介支点的复杂转子系统支点振动响应优化设计提供了理论方法。

Aimed at the bearing dynamic load vibration response and optimal design of a complex rotor system with inter-shaft bearing in a turbofan engine with high thrust-to-weight ratio,a mechanical model of bearing dynamic loads is established to study the effects of unbalance,bending deformation and inertia moment under different rotational speeds. The variation trend of the bearing dynamic loads of a dual-rotor system with rotating speeds is calculated and analyzed. The relationship between the dynamic load of inter-shaft bearing and rotor bending deformation as well as inertial loads is revealed. An optimal design method for the vibration response of the inter-shaft bearing based on the slope control of the elastic curves of the rotors is proposed. The results show that by optimizing the rear journal structure of the high pressure turbine and adjusting the rear bearing of the low pressure turbine near the inter-shaft bearing,the dynamic load of the inter-shaft bearing and the sensitivity of the unbalance can be effectively reduced,which provides a theoretical method for the optimal design of the bearing vibration response of a complex rotor system with inter-shaft bearing.