齿根裂纹对齿轮轮体及齿间耦合刚度的影响研究

Study on the Effect of Tooth Root Crack on Gear Body Stiffness and Coupling Stiffness between Adjacent Teeth

齿根疲劳裂纹是齿轮传动系统服役过程中最常见的失效形式之一,威胁着齿轮传动系统甚至装备的运行安全,开展齿轮传动系统齿部故障诊断具有重要意义,而其核心是齿根裂纹故障的动态作用机制及振动特征。然而,传统啮合刚度计算模型尚未考虑齿根裂纹对齿间耦合作用的影响。针对该问题,分析了齿轮轮体结构变形引起的齿间耦合作用机制,建立了轮体刚度计算的有限元模型,研究了作用力、轮毂孔半径及齿根裂纹深度等参数对轮体刚度,特别是齿间耦合刚度的影响规律。结果表明,齿根裂纹对轮体变形引起的轮体刚度与齿间耦合刚度具有显著的影响,在齿根裂纹时变啮合刚度激励计算中应予以考虑,从而提高齿根裂纹刚度激励计算模型的准确性。

Tooth root fatigue crack is one of the most common failure forms in the service process of gear transmission system,and it will threaten the safety of gear transmission systems or even the whole equipment.It is of great significance to carry out the fault diagnosis of the gear tooth in gear transmissions,where the dynamic action mechanism and vibration feature of the tooth root crack fault are the core.However,the influence of tooth root rack on tooth coupling has not be considered in the traditional calculation model of gear mesh stiffness.With respect to this problem,a finite element model of a spur gear is established to analyze the coupling mechanism between the adjacent teeth caused by the structural deformation of the gear body.And the effect of the force,the hub hole radius and the depth of tooth root crack on gear body stiffness are investigated,especially for the coupling stiffness between the adjacent teeth.The results show that the tooth root crack has a significant effect on both the gear body stiffness and the coupling stiffness between the adjacent teeth,which should be considered in the excitation calculation of the time-varying mesh stiffness with the presence of tooth root crack,so as to improve the accuracy of gear excitation model with tooth root crack.