Abstract: In order to study the vibration characteristics of the downhole gear transmission system,based on the 3D modeling software CREO, a three⁃dimensional geometric model of the main and driven gears of the downhole gear transmission system was established. And using the ANSYS software import function to establish the three⁃dimensional finite element model of transmission gear. By reading the dynamic mechanical modal analysis of the finite element model of gear, the natural frequencies of the gears and the corresponding main modes are obtained. This study can be used as a theoretical reference to avoid the frequency of external excitation response in the design process, so as to avoid the resonance of the transmission system and effectively improving the fatigue strength of the gear transmission system.

Key words: Gear, Modal analysis, Finite element, Natural frequency, K?vibration

摘要： 为研究井下齿轮传动系统的振动特性，基于三维建模软件CREO建立井下齿轮传动系统主、从动齿轮的三维几何模型，采用大型分析软件ANSYS，建立了井下主、从动齿轮的有限元仿真模型，并通过读取结果文件中井下主、从动齿轮在不同阶数下的固有频率及对应振型，直观地分析了井下主、从动接触齿轮的动态特性。该振动分析结果可为传动机构设计阶段优化齿轮参数以远离外界激励频率提供理论参考，从而避免齿轮传动系统发生共振，并有效地提高齿轮传动系统的疲劳强度。

关键词: 齿轮, 　模态分析, 　有限元, 　固有频率, 　振型