基于并联机构的三维动力吸振器各向同性设计及减振特性研究

Isotropy Design and Vibration Reduction of a Three-dimensional Dynamics Vibration Absorber Based on Parallel Mechanisms

针对动力机械设备的多维线谱耦合振动控制问题,提出一种基于并联机构的三维动力吸振器,它具有模块化、附加质量小等优点。构造出采用一组关节坐标刻画的动力学方程,在此基础上推导出该新型动力吸振器的模态解析解,得到动力学各向同性条件,并据此设计出一款可抑制50 Hz线谱振动的动力吸振器。探讨了该动力吸振器在动力机械设备多维线谱耦合振动控制中的有效性及优势。分析结果表明:不同于单向动力吸振器仅能抑制其自由度方向的线谱振动,新型三维动力吸振器在三个垂直方向上对50 Hz附近线谱振动的最大减振效果均高于7 dB。

Aiming at the multi-dimensional line-spectra coupling vibration control of power machines,a novel three-dimensional DVA was presented based on parallel mechanisms.The novel DVA has the merits of good modularity and small additional mass.On the basis of the establishment of dynamics model in terms of a set of joint coordinates,the modal analytical solution for modal analysis of the DVA was derived,leading to the condition to achieve dynamics isotropic design,and thereby a three-dimensional DVA reducing the line spectra vibration at 50 Hz was obtained.In addition,the effectiveness and advantages of the novel DVA in the applications on line-spectra vibration suppression of power machines were investigated.The results show that the maximum attenuations of the line spectrum response at around 50 Hz along three mutual vertical directions are all above 7 dB after the installation of the three-dimensional DVA,while only the line spectrum response along the direction of freedom may be suppressed effectively after the installation of the unidirectional DVA.