齿轮传动系统若干动力学问题研究

发布时间：2018-06-18 19:56

本文选题：行波共振 + 集总参数法　；参考：《东北大学》2015年博士论文

【摘要】：齿轮传动系统是机械中最常用的传动形式之一,由于其恒功率传动的特点,具有其它传动形式不可替代的优势。目前,齿轮系统正朝着高速、重载、轻型、高精度和自动化方向发展,这就对其动态性能提出了更高的要求。齿轮系统动力学、减振和降噪及其优化已成为当前科技界研究的非常活跃的前沿课题之一。汽车变速器、风机增速箱及附件机匣等均是以它们的内部齿轮传动系统为主要结构的动力转换和传递机构,由于其功能和应用背景的需要存在的减振降噪,重载下的均载和冲击强度及结构优化等动力学问题均是齿轮传动系统的典型共性问题,本文的研究就是以某型汽车变速器、某发动机附件机匣及1.5MW风机增速箱行星传动系统为对象,综合运用机械振动、有限元理论和分析方法、多体动力学方法、智能优化算法、集中参数方法、边界元噪声分析方法、模态综合法等,对变速器、机匣传动系统、风机增速箱行星轮系统的直齿和斜齿轮耦合传动系统的动力学特性、内部激励、修形减振优化、振动噪声和动态冲击强度及结构优化等问题进行了深入研究,该研究对了解齿轮系统的结构型式、几何参数及加工方法等对齿轮传动系统动态性能的影响具有一定价值,从而指导高质量齿轮系统的设计和制造,同时对齿轮传动系统的减振及噪声控制提供了有力的理论基础。具体而言,本文完成的工作如下：(1)研究了高速多载荷的弹性支撑锥齿轮轴系的动力学特性和行波共振特性；建立的轴系动力学模型考虑了多个齿轮副啮合的耦合作用及轴承弹性支撑,分析了不同支撑刚度下的临界转速分布和共振响应点的分布,利用应变能密度分布法分析了不同行波共振振形对锥齿轮轴系的危害程度。(2)基于静态接触方法,获得时变啮合刚度,并结齿面误差和啮合冲击激励合成了齿轮啮合激励；提出利用弹性齿轮-轴-轴承的刚-柔耦合动力学模型和基于显式动力学的动态接触方法对斜齿轮轴系内部啮合激励进行研究,对比分析齿轮副中心距变化和弹性齿轮-轴-轴承对内部啮合激励的影响,弹性齿轮-轴-轴承导致啮合激励的频率成分增加,且频率成分在啮合频率及其倍频、分频和转频周围成梳状分布的结论与试验结论一致。(3)提出基于显式动力学和多体动力学方法及遗传算法的直齿和斜齿轮优化修形方法。利用多体动力学方法获取齿轮副轴系由于齿轮-轴-轴承变形引起的齿轮副啮合误差,考虑齿轮副啮合误差,建立齿轮副修形有限元模型,并利用显式动力学方法求解,以齿面最大应力为判别依据,利用遗传算对修形参数进行优化。此修形方法更加符合工程实际,修形参数取值能够明显降低实际工况下的齿面应力。(4)以斜齿行星齿轮传动系统为研究对象,建立了斜齿行星齿轮传动系统全自由度集总参数动力学模型。考虑安装误差、加工误差和时变啮合刚度等因素,对风机增速箱行星轮系进行了动力学特性研究。研究表明,在工作转速下太阳轮和行星轮处于混动运动状态,振动频率存在啮合频率和差频,由于安装误差导致的星轮系不平衡载荷影响太阳轮轴心轨迹成不规则椭圆形,振动位移指标明显增大。对故障增速箱的测试信号进行时域和频域分析,并将故障信息与增速箱固有特性进行对比分析,确定了故障原因和故障位置。(5)提出结合显式动力学方法和边界元方法进行变速器噪声分析。利用弹性齿轮-轴-轴承动力学模型获取变速器壳体动态轴承激励,用于变速器壳体的噪声分析。首先分别建立变速器输入、输出、差速器轴系动力学模型,对轴承激励进行模拟仿真,将仿真获得的轴承动态激励施加在变速器壳体的轴承支撑部位,分析各轴承激励综合作用下变速器壳体在不同频率下的表面振速；建立变速器壳体边界元模型,通过噪声分析获得变速器表面和声场范围内的噪声分布及主要分布位置。此方法在获取变速器壳体轴承激振力中考虑了弹性轴、齿轮、轴承的综合影响,轴承激振力更加合理,噪声分析精度更高。(6)将Matlb与Ansys的APDL语言相结合,建立加力泵齿轮轴系半参数化模型,对瞬间高速冲击的极端工况下附件机匣加力泵齿轮轴动态强度和结构优化进行了研究,并开发了齿轮轴系动态强度及优化分析软件。分别利用隐式和显式动力学求解方法对加力泵齿轮轴在高速冲击载荷下的应力进行仿真分析,分析结果表明,两种方法获得的应力水平分布基本一致,但是动态冲击载荷下的动应力水平远大于平衡应力,显式动力学求解方法获得的动态冲击应力水平和最大应力分布位置更加接近试验结果。(7)利用模态综合法建立了连续参数的齿轮轴转子系统动力学微分方程,对柔性轴-弹性齿轮盘-弹性轮齿构成的齿轮轴转子系统的固有频率和振形进行了分析求解,并对轴和齿轮盘的质量、刚度对系统固有特性的影响进行了分析讨论。
[Abstract]:Gear transmission system is one of the most commonly used transmission forms in machinery. Because of its characteristic of constant power transmission, it has the irreplaceable advantages of other transmission forms. At present, the gear system is developing towards high speed, heavy load, light, high precision and automatic direction, which puts forward higher requirements for its dynamic performance. Gear system dynamics, reduction. Vibration and noise reduction and its optimization have become one of the most active frontiers in the field of science and technology. Automobile transmission, fan speed increase box and accessory box are all power conversion and transmission mechanism with their internal gear transmission system as the main structure. The dynamic problems such as average load, impact strength and structure optimization are the typical common problems of gear transmission system. The research in this paper is based on a certain type of automobile transmission, an engine accessory box and the 1.5MW fan speed increase box planetary transmission system, and the mechanical vibration, the finite element theory and the analysis method, the multi-body dynamics square. Method, intelligent optimization algorithm, centralized parameter method, boundary element noise analysis method, modal synthesis method and so on, the dynamic characteristics, internal excitation, modification, vibration noise and dynamic impact strength and structure optimization of the transmission system of transmission, casing transmission, fan speed increase box planetary gear system and the coupling transmission system of helical gear and helical gear system. A thorough study is carried out. The study has a certain value on understanding the dynamic performance of gear transmission system, which is of certain value to understand the structural type, geometric parameters and machining methods of the gear system, thus guiding the design and manufacture of the high quality gear system, and providing a powerful theoretical basis for the vibration reduction and noise control of the gear transmission system. The work completed in this paper is as follows: (1) the dynamic characteristics and traveling wave resonance characteristics of the elastic braced bevel gear shafting with high speed and multiple loads are studied. The dynamic model of the shaft system is built to consider the coupling effect of multiple gear meshing and the elastic support of the bearing, and the critical speed distribution and resonance response under the different support stiffness are analyzed. The damage degree of different traveling wave resonance shapes to bevel gear shafting is analyzed by the strain energy density distribution method. (2) based on the static contact method, the time varying meshing stiffness is obtained, and the gear meshing excitation is synthesized by the tooth surface error and the meshing impact excitation, and the rigid flexible coupling dynamic model of the elastic gear shaft bearing is proposed. The dynamic contact method based on explicit dynamics is used to study the internal meshing excitation of the helical gear shafting. The change of the center distance of the gear and the effect of the elastic gear shaft bearing on the internal meshing excitation are compared and analyzed. The frequency component of the meshing excitation is increased by the elastic gear shaft bearing, and the frequency component is at the meshing frequency and frequency doubling and frequency division. The conclusion of the comb distribution around the frequency around the frequency is consistent with the experimental conclusion. (3) an optimization method of straight tooth and helical gear modification based on explicit dynamics and multibody dynamics method and genetic algorithm is proposed. The meshing error of gear pair caused by the gear axis bearing deformation is obtained by using the multi body dynamics method, and the gear pair engagement is considered. Error, set up the finite element model of gear pair repair, and use the explicit dynamic method to solve it, take the maximum stress of the tooth surface as the criterion, and optimize the modification parameters by genetic calculation. The modification method is more in line with the engineering practice. The modification parameters can obviously reduce the stress of the tooth surface under the actual working condition. (4) the helical planetary gear transmission As the research object, the total parameter dynamic model of the total freedom degree of the helical planetary gear transmission system is established. Considering the installation error, the machining error and the time varying meshing stiffness, the dynamic characteristics of the planetary gear train of the fan speed increase box are studied. The research shows that the sun wheel and the planetary wheel are in the mixed motion at the working speed. The vibration frequency has meshing frequency and difference frequency. Because of the unbalance load of the star wheel system caused by the installation error, the axis trajectory of the sun wheel is irregular ellipse, and the vibration displacement index is obviously increased. The time and frequency domain analysis of the test signal of the fault growth box is carried out, and the barrier information is compared with the inherent characteristics of the speed increase box. The cause and fault location of the fault are determined. (5) an explicit dynamic method and a boundary element method are proposed to analyze the transmission noise. The dynamic bearing excitation of the transmission shell is obtained by the elastic gear shaft bearing dynamic model, which is used for the noise analysis of the gearbox. First, the transmission input, output, differential axis movement are set up. The mechanical model is used to simulate the bearing excitation, and the bearing dynamic stimulation obtained by the simulation is applied to the bearing support part of the gearbox, and the velocity of the surface vibration of the transmission shell under different frequencies is analyzed. The boundary element model of the transmission shell is established, and the surface harmony of the transmission is obtained through the noise analysis. The noise distribution and the main distribution position in the field range. This method takes into account the comprehensive influence of the elastic axis, the gear and the bearing in obtaining the exciting force of the bearing of the transmission shell, and the exciting force of the bearing is more reasonable and the precision of the noise analysis is higher. (6) combining Matlb with the APDL language of Ansys, the semi parameterized model of the gear shaft system of the loading pump is set up for a moment. The dynamic strength and structural optimization of the gear shaft of the appendage pump are studied under the extreme conditions of high speed impact, and the dynamic strength and the optimization analysis software of the gear shaft system are developed. The stress of the gear shaft under the high speed impact load is simulated and analyzed by the implicit and explicit dynamic solving methods. The distribution of stress level obtained by the two methods is basically the same, but the dynamic stress level of the dynamic impact load is far greater than the equilibrium stress. The dynamic impact stress level and the maximum stress distribution position obtained by the explicit dynamic solution approach are closer to the test results. (7) the continuous parameters of the gear shaft rotor are established by using the modal synthesis method. The differential equation of system dynamics is analyzed and solved for the natural frequency and vibration shape of the gear shaft rotor system composed of flexible axles and elastic gear teeth. The influence of the mass and stiffness of the shaft and gear disk on the inherent characteristics of the system is analyzed and discussed.
【学位授予单位】：东北大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH132.41

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