Abstract: The conventional vibration isolation system of vehicle power packs might not guarantee both of the low-frequency vibration isolation performance and high load-bearing stability. New methods and new technologies were urgently demanded to achieve the unity of them. The influences of the stiffness in different regions on the isolation performance and stability were analyzed, and a novel isolation configuration was proposed, which consisted of preloaded constant spring with variable spring in parallel. Design method of the proposed variable vibration isolators was illustrated, where the stiffnesses and preloads of constant spring were determined based on vibration isolation ratio and payload, and parameters of variable spring were optimized based on stability requirements. The new vibration isolator has high payload capacity and wide frequency domain of vibration isolation, and particularly, the isolation performance in low-frequency working domain is significantly improved. Experimental results on a new special vehicle by adopting the proposed vibration isolation system show that, besides guarantee of sufficient stability, the vibration isolation ratio is increased from 30.3% to 83.5% under rated working conditions.

Key words: vehicle power pack, variable stiffness, vibration isolation, stability

摘要： 常规的车辆动力装置隔振系统无法兼顾低频隔振性能和高承载稳定性，迫切需要新方法、新技术实现两者统一。在分析不同行程区间刚度特性对隔振率和稳定性影响的基础上，提出了预压定刚度弹簧与变刚度弹簧并联的变刚度隔振新构型，阐述了依据隔振率和负载匹配定刚度及预压参数、依据稳定性优化变刚度参数的设计方法。新型隔振器不仅支承能力强，而且隔振频域宽，尤其是低频工作域的隔振效果显著提升。实车测试结果表明，在保证足够稳定性的提前下，额定工况下新型变刚度隔振系统的隔振率由原来的30.3%提高至83.5%。

关键词: 车辆动力装置, 变刚度, 隔振, 稳定性