考虑裂纹与磨损故障的齿轮传动系统动态特性分析

Dynamic Characteristics Analysis of Gear Transmission System Considering Crack and Wear Fault

针对齿轮系统中同时出现裂纹与磨损故障时实现复合故障诊断较为困难的问题,提出了考虑齿廓磨损和齿根裂纹故障的齿轮传动系统动态特性分析模型。首先,基于Archard公式,建立齿轮传动系统磨损数值仿真模型,求解不同磨损周期下的齿廓磨损量;然后,通过势能法建立裂纹及磨损作用下的单齿啮合刚度计算模型,在双齿接触区考虑啮合齿对磨损量间的关系,结合变形协调,建立双齿啮合刚度计算模型;最后,采用集中质量法建立齿轮系统4自由度动力学模型,以含故障的时变啮合刚度为输入,使用Newmark-β法对动态响应进行求解,获得不同程度裂纹与磨损作用下的齿轮动态特性。实验结果表明:该模型能够较好反应复合故障中磨损与裂纹特征;与未考虑磨损后双齿区实际变形的裂纹与磨损复合故障模型相比,该复合故障模型双齿区刚度计算准确性提高了约22%,所提模型可为含磨损与裂纹的齿轮传动系统故障诊断提供有效的动力学补充。

In response to the difficulty of composite fault diagnosis when cracks and wear faults occur simultaneously in gear system,a dynamic characteristic analysis model of gear transmission system considering profile wear and root cracks is proposed.Firstly,a numerical simulation model of gear transmission system wear is established based on Archard formula to solve the tooth profile wear under different wear cycles.Then,the meshing stiffness calculation model of single tooth under the action of crack and wear is established by the potential energy method.The relationship between meshing teeth and wear is considered in the contact area of double teeth,and the meshing stiffness calculation model of double teeth is established combined with deformation coordination.Finally,a 4-DOF dynamic model of the gear system is established by using the centralized mass method,and the dynamic response is solved by using the Newmark-βmethod with time-varying mesh stiffness with faults as the input.The dynamic characteristics of the gear under different degrees of cracks and wear are obtained.The experimental results show that the model can reflect the wear and crack characteristics of composite faults well.Compared with the crack and wear composite fault model without considering the actual deformation of the double teeth region after wear,the accuracy of the stiffness calculation of the double teeth region of the composite fault model is improved by about 22%.The proposed model can provide an effective dynamic supplement for the fault diagnosis of the gear transmission system with wear and crack.