中文摘要：

以液压挖掘机为研究对象，将工作装置向回转传动机构行星齿轮传动系统进行等效转换，得到工作装置等效转动惯量表达式。在考虑工作装置基础上建立回转传动机构扭振固有频率的计算公式，分析工作装置等效转动惯量对回转传动机构扭振固有频率的影响，揭示回转传动机构扭振固有频率与其结构参数及位置参数之间的内在关系。研究表明，回转传动机构扭振固有频率不仅取决于自身的结构参数，而且还取决于工作装置等效转动惯量的大小，即还取决于工作装置的结构参数和位置参数。最后通过实例进行仿真分析。

英文摘要：

A hydraulic excavator is taken as an object to study.The working device is equivalently transferred to the planetary gear train of slewing transmission mechanism. The equivalent moment of inertia of working device is obtained.Considered the working device ,the equation of natural frequency of torsional vibration of the slewing transmission mechanism is established.According to the equation,the effect of the working device on natural frequency of torsional vibration of the slewing transmission mechanism is analyzed.The relations between the natural frequency of torsional vibcation of the slewing transmission mechanism and both the structure parameters and the position parameters of the working device are discov- ered.The results show that the natural frequency of torsional vibration of the slewing transmission mecha- nism is not only related to its structure parameters ,but also to the structure parameters and the position pa- rameters of the working device.Lastly,an example is given.