几种特殊弹性参数对动力总成-悬置系统固有振动特性的影响

Influence of elastic parameters on the natural vibrational characteristics of powertrain mounting system

为了研究几种特殊弹性参数对动力总成-悬置系统固有振动特性的影响,分别建立了考虑悬置元件的角变形刚度和发动机前端驱动风扇的传动带弹性约束作用的动力总成-悬置系统的振动分析模型。以几种常见车型为例计算了考虑悬置元件角变形刚度前、后动力总成-悬置系统的固有振动特性,同时计算了系统的各阶固有振动频率关于传动带的等效刚度和安装角度参数的变化历程。结果表明:在考虑角变形刚度前、后,动力总成-悬置系统固有振动特性的变化很小;当传动带的刚度逐渐增大时,系统的最高阶振动模态(以侧倾振动为主)频率显著提高;传动带安装角度的增加使第2至6阶固有振动频率产生较大变化。因此,在动力总成-悬置系统固有振动特性的计算过程中一般可以忽略悬置元件角变形刚度影响;而传动带的弹性约束作用则可能显著影响系统的固有振动特性,在建模和计算的过程中应予以重点关注。

The influence of several elastic parameters on the natural vibrational characteristics of powertrain mounting system was analyzed using a dynamic model of the powertrain mounting system including the angular stiffness of the mounts and the flexible drive belt on the front of the engine.The natural vibrational characteristics of powertrain mounting system on several kinds of vehicles were analyzed with and without considering the angular stiffness of the mounts with parametric studies of the natural frequencies and mode shapes for various drive belt stiffnesses and orientation angles.The results show that natural vibrational characteristics of the powertrain mounting system are affected little by the angular stiffness of the mounts with the highest modal frequency（the mode shape is mainly rolling dominant） of the powertrain increasing notably with belt stiffness.Changes in the orientation angle have a notable influence on the 2nd to 6th natural vibration frequencies.Thus,the influence of the angular stiffness can be neglected,but the flexible drive belt strongly influences the system natural vibrational characteristics and should be included in powertrain mounting system models.