齿轮传动系统故障模拟综合实验台设计与仿真

发布时间：2019-06-12 02:27

【摘要】：齿轮故障、轴承故障和转子不平衡是齿轮(机械)传动系统中最常见的故障类型。在工程实际中,机电设备由于这三类故障未能及时发现而引起的重大事故屡有发生。对此类设备开展状态监测和故障诊断,已成为大型企业的迫切需求,也必将带来巨大的经济效益和社会效益。而对于在校师生,接触和了解工程实际中的设备和情况是必要的,但由于现场设备所处环境和工况往往非常复杂,所以在学习和研究时,需要从简入难,由少到多。因此,设计一台可以模拟工程实际中机械传动系统常见故障的实验台就有很重要的理论和实际意义。论文设计了一台集合轴承、齿轮、转子不平衡故障模拟于一体的齿轮(机械)传动系统实验台。研究内容主要包含实验台的结构设计、关键部件理论分析和试验台的三维建模及故障动力学仿真。(1)设计了多功能、操作便捷的故障模拟实验台。该试验台能实现以下功能：在实验室的环境下,通过可更换模拟局部缺陷的轴承、齿轮以及不同配重的动不平衡转子重现旋转机械典型故障。如不平衡、不对中、齿轮典型故障、轴承典型故障等。实验装置要便于完成数据信号的采集及观察,主要包括转速、位移、加速度等信息数据。操作方便,做不同故障实验时,时间间隔要短。实验装置输出的故障信息要明显并且尽可能具有单一性,信噪比要高,便于获得与故障相对应的时域图和频谱图。(2)实验台关键零部件的力学性能校核。论文齿轮(机械)传统系统模拟试验台的关键零部件进行强度校核及有限元静力学分析、结构改进及优化。设计可更换零件,模拟轴承、齿轮、转子平衡的典型故障。(3)实验台动力学建模及仿真。分别建立了实验台的轴承子系统和齿轮传动子系统的非线性动力学模型。对于轴承子系统,考虑滚珠滑移、油膜间隙和非线性接触力等因素。针对轴承外滚道及内滚道点蚀缺陷,建立相应的系统动力学模型,并推导相应的动力学微分方程,基于MALAB软件数值求解器,仿真系统的振动加速度信号。对仿真信号进行时域和频域分析,研究故障类型与故障特征的映射关系,并与理论分析对比验证,归纳轴承内滚道及外滚道缺陷的时域和频域特征。针对齿轮传动子系统,考虑齿轮时变啮合刚度、传动误差等因素,建立非线性动力学模型,并齿轮裂纹、断齿故障以时变啮合刚度激励的形式体现到系统动力学模型中,进而仿真故障状态下的系统动态响应,并分析其时域和频域特征。
[Abstract]:Gear fault, bearing fault and rotor imbalance are the most common types of fault in gear (mechanical) transmission system. In engineering practice, the major accidents caused by these three kinds of faults can not be found in time. It has become an urgent demand for large enterprises to carry out condition monitoring and fault diagnosis for this kind of equipment, and it will also bring great economic and social benefits. For teachers and students in school, it is necessary to contact and understand the equipment and situation in engineering practice, but because the environment and working conditions of the field equipment are often very complex, it is difficult to learn and study from simple to small. Therefore, it is of great theoretical and practical significance to design an experimental platform which can simulate the common faults of mechanical transmission system in engineering practice. In this paper, a gear (mechanical) transmission system experimental platform is designed, which simulates the unbalanced fault of bearing, gear and rotor. The research contents mainly include the structure design of the experimental platform, the theoretical analysis of the key components, the three-dimensional modeling and fault dynamics simulation of the test-bed. (1) A multifunctional and convenient fault simulation experimental platform is designed. The test-bed can realize the following functions: in the laboratory environment, the typical faults of rotating machinery can be reproduced by replacing bearings, gears and dynamic unbalanced rotors with different counterweights. Such as imbalance, misalignment, gear typical failure, bearing typical fault and so on. The experimental device should be convenient to collect and observe the data signal, including speed, displacement, acceleration and other information data. The operation is convenient and the time interval should be short when doing different fault experiments. The fault information outputted by the experimental device should be obvious and as single as possible, and the signal-to-noise ratio (SNR) should be high, which is convenient to obtain the time domain diagram and spectrum diagram corresponding to the fault. (2) the mechanical properties of the key parts of the experimental platform are checked. In this paper, the strength check, finite element statics analysis, structure improvement and optimization of the key parts of the gear (mechanical) traditional system simulation test-bed are carried out. Design replaceable parts to simulate typical faults of bearing, gear and rotor balance. (3) dynamic modeling and simulation of experimental platform. The nonlinear dynamic models of bearing subsystem and gear transmission subsystem of the experimental platform are established respectively. For bearing subsystem, ball slip, oil film clearance and nonlinear contact force are considered. Aiming at the pitting defects of bearing outer raceway and inner raceway, the corresponding system dynamics model is established, and the corresponding dynamic differential equation is derived. based on the numerical solver of MALAB software, the vibration acceleration signal of the system is simulated. The time domain and frequency domain analysis of the simulation signal is carried out, the mapping relationship between fault type and fault characteristics is studied, and compared with the theoretical analysis, the time domain and frequency domain characteristics of bearing inner raceway and outer raceway defects are summarized. For the gear transmission subsystem, considering the time-varying meshing stiffness and transmission error of the gear, the nonlinear dynamic model is established, and the gear crack and broken tooth fault are reflected in the system dynamics model in the form of time-varying meshing stiffness excitation, and then the dynamic response of the system under the fault state is simulated, and its time-domain and frequency-domain characteristics are analyzed.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH132.41

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