斜齿轮裂纹故障动态激励机理与振动特征演变规律研究

It’s difficult to identify the early crack fault in helical gears for the problem that it lack of research on the dynamic excitation mechanism and evolutionary law of vibration characteristics for helical gears as tooth crack initiate and propagate to breakage. To solve this problem, the project will start with investigating the stiffness excitation and fault excitation, and a series research about the dynamic excitation and vibration characteristics of helical gears with tooth crack will be carried out. The main research contents include:(1)The analytical models to calculate the time-varying mesh stiffness for helical gears with and without tooth crack will be proposed. The effects of shape, position, size and angle of tooth crack on mesh stiffness of helical gears will be studied. (2)The algorithm of displacement excitation and stiffness excitation of plastically inclined tooth with crack will be studied. The dynamic model of helical gears with plastically inclined tooth and crack will be modeled. The influence of plastically inclined tooth with crack on the vibration characteristics of helical gears with found out. (3)The algorithm of displacement excitation and stiffness excitation during the process of evolution in helical gear with tooth crack will be studied. The dynamic model of helical gears during the process of tooth breathing crack evolution will be modeled. The evolutionary law of vibration characteristics induced by the process of tooth breathing crack evolution in helical gears will be revealed. The purposes of this work are to provide some new methods and theoretical bases for the extraction and detection of vibration characteristics caused by the initiation and evolution of the incipient defects in helical gears.

轮齿裂纹萌生、扩展至断裂过程的动态激励机理及其诱发的齿轮振动特征演变规律的研究尚显不足，导致斜齿轮早期裂纹故障识别困难。针对该问题，本项目从斜齿轮裂纹故障刚度激励和位移激励入手，开展斜齿轮裂纹故障动态激励与振动响应特征的研究。具体研究内容包括:（1）提出正常和裂纹故障斜齿轮时变啮合刚度解析计算模型，研究裂纹形态、位置、尺寸及角度等对斜齿轮啮合刚度的影响；（2）研究裂纹轮齿塑性偏转变形故障位移激励与刚度激励算法，建立斜齿轮裂纹轮齿塑性偏转变形故障动力学模型，查明裂纹轮齿塑性偏转变形对斜齿轮振动响应特征的影响规律。（3）研究轮齿裂纹故障演化过程的时变刚度算法和时变位移激励算法，建立呼吸式轮齿裂纹故障演化过程的动力学模型，揭示轮齿裂纹故障演化过程中诱发的斜齿轮振动特征的演变规律。本项目的研究旨在为早期故障动态演化过程中齿轮振动特征的提取与识别提供新的方法和理论支撑。

本项目针对斜齿轮故障激励建模及其动态特征问题,从斜齿轮裂纹故障刚度激励和位移激励入手,开展了斜齿轮啮合内部动态激励与外部振动响应的研究。提出了正常和裂纹故障斜齿轮时变啮合刚度的解析计算模型，研究了不同裂纹形式对斜齿轮啮合刚度的影响；建立了轮齿裂纹故障斜齿轮动力学模型，获得了不同裂纹形式对斜齿轮振动响应特征的影响规律；构建了斜齿轮裂纹轮齿塑性偏转变形故障时变位移激励算法和综合啮合刚度激励模型，解明了裂纹故障及轮齿塑性偏转变形故障对斜齿轮振动特征的影响机制；构建了呼吸式裂纹故障时变刚度激励算法，揭示裂纹故障诱发的斜齿轮振动特征的演变规律。提出了一种双压力角分段渐开线齿轮，提高了齿根弯曲强度、齿面接触强度和轮齿的承载能力；发明了一系列的变位消隙传动齿轮，有效地消除或减少了齿侧间隙及回差；提出了一种可自动控制齿轮油温和压力的高可靠性大功率重载齿轮箱及齿轮传动误差测量方法。项目研究成果完善了斜齿轮裂纹故障内部激励计算方法，为早期裂纹故障萌生与扩展过程中的齿轮振动特征的识别和故障诊断提供理论支撑；从齿形和结构等方面出发，提高了齿轮的强度和传动精度，从根源上降低了齿轮故障的出现。