In high-speed gear transmission, cavitation occurs easily due to vibration. When gear has pitting or crack fault, the cavitation will be more violent due to stronger vibration, causing potential safety hazards. However, researches on gear cavitation mechanism considering pitting and crack are limited. For studying the cavitation mechanism of faulty gear, a model combined computational fluid dynamics and faulty gear dynamics has been proposed, being regarded as the innovation of this paper. The dynamic characteristics of the faulty gear is obtained by solving the gear finite element model, and the results will be applied to the analysis of lubricating oil flow characteristics as boundary conditions. For proving the validity of the proposed model, the simulation results are compared with the available experimental results. Moreover, the novelty of this paper is to consider the influence of gear failures on cavitation, factors such as rotational speed, pitting depth and crack depth are discussed, tooth profile changes are also considered. The results indicate that gear faults have greater impact on cavitation at high speeds. At 10,000 rpm, with the deepening of pitting, the cavitation intensity will increase firstly and then decrease. When the pitting depth increases from 0.2 mm to 0.3 mm, the root mean square value of average vapour volume fraction decreases from 0.0752 to 0.0724. For cracked gears, the crack depth will affect the cavitation enhancement rate. The increase rate of cavitation decreases from 17.4 to 1.1% when crack depth increases from 1 to 4.5 mm. This study provides an effective tool for gear cavitation suppression and high reliability.

在高速齿轮传动中，由于振动容易产生气蚀现象。当齿轮出现点蚀或裂纹故障时，由于振动较强，气蚀现象会更加剧烈，造成安全隐患。然而，考虑点蚀和裂纹的齿轮空化机理的研究是有限的。为了研究故障齿轮的空化机理，提出了计算流体动力学和故障齿轮动力学相结合的模型，被认为是本文的创新点。通过对齿轮有限元模型求解得到故障齿轮的动态特性，并将所得结果作为边界条件应用于润滑油流动特性的分析。为了证明所提出模型的有效性，将仿真结果与可用的实验结果进行了比较。而且，本文的新颖之处在于考虑了齿轮失效对气蚀的影响，讨论了转速、点蚀深度和裂纹深度等因素，还考虑了齿形变化。结果表明，齿轮故障对高速时的气蚀影响更大。在10000rpm时，随着点蚀的加深，空化强度先增大后减小。当点蚀深度从0.2 mm增加到0.3 mm时，平均蒸气体积分数的均方根值从0.0752减小到0.0724。对于裂纹齿轮，裂纹深度会影响空化强化率。当裂纹深度从1 mm增加到4.5 mm时，空化的增加率从17.4%降低到1.1%。本研究为齿轮气蚀抑制和高可靠性提供了有效的工具。