随机风载作用下风力发电机齿轮传动系统动态可靠性分析

运用最小二乘支持向量机(Sparse least squares support vector machines,SLS-SVM)机器学习方法建立风场随机风速模型,根据随机风速模型和空气动力学理论得到随机风引起的系统外部载荷激励,建立考虑齿轮时变啮合刚度和滚动轴承时变刚度的风力发电机行星齿轮传动系统齿轮—轴承耦合动力学模型,并对动力学模型进行仿真计算,分别得到各齿轮副的动态啮合力和滚动轴承动态接触力。以此为基础,将载荷作用过程视为随机过程,推导出随机载荷作用下的等效载荷累计分布函数。根据应力—强度干涉理论建立风力发电机齿轮传动系统各齿轮和轴承的动态可靠性模型,利用二阶矩和摄动方法求出各齿轮、轴承的动态可靠性指标,并计算出动态可靠度,研究各齿轮、轴承和传动系统的动态可靠度随时间的变化规律,为风力发电机齿轮传动系统动态可靠性设计奠定了基础。     

基于层级有限元法的大型航空行星机构可靠性优化设计

大型航空行星机构作为多种重型航空器传动系统的基础与核心,它的可靠性水平在很大程度上制约着航空器的经济可承受性与服役安全性。将某型号重型直升机行星机构作为研究对象,以保证和提高该系统的疲劳可靠性水平为目标,利用层级有限元法计算系统全局弹性行为耦合作用下的轮齿疲劳载荷历程,并基于齿轮低周疲劳试验与最小次序统计量转化方法拟合出轮齿概率疲劳强度,为系统可靠性预测模型提供经济有效的载荷与强度输入变量。据此,建立从大型航空行星机构关键结构要素到系统可靠性指标的映射路径,提出可靠性驱动的行星机构结构尺寸多目标优化设计新方法。最后,分析了内齿圈轮缘厚度与行星架基板厚度对行星轮系疲劳可靠性的影响规律,并得到了指定型号的大型航空行星机构的轮缘与基板尺寸最佳刚度匹配结果,最大限度地发挥了核心结构要素的刚度潜力,以此平衡大型航空行星装备在可靠性与轻量化要求之间的矛盾。     

Life Distribution Transformation Model of Planetary Gear System

Planetary gear systems have been widely used in transportation, construction, metallurgy, petroleum, aviation and other industrial fields. Under the same condition of power transmission, they have a more compact structure than ordinary gear train. However, some critical parts, such as sun gear, planet gear and ring gear often suffer from fatigue and wear under the conditions of high speed and heavy load. For reliability research, in order to predict the fatigue probability life of planetary gear system, detailed kinematic and mechanical analysis for a planetary gear system is firstly completed. Meanwhile, a gear bending fatigue test is carried out at a stress level to obtain the strength information of specific gears. Then, a life distribution transformation model is established according to the order statistics theory. Transformation process is that, the life distribution of test gear is transformed to that of single tooth, and then the life distribution of single tooth can be effectively transformed to that of the planetary gear system. In addition, the effectiveness of the transformation model is finally verified by a processing method with random censoring data.     

时变位姿下行星齿轮传动系统动应力计算模型及其参数影响研究

考虑行星轮系内部非惯性和机体时变位姿外部非惯性的综合影响,推导了任意时变位姿下带有机匣的行星轮系构件运动方程,计入时变啮合刚度、啮合误差、侧隙和啮入冲击,建立了时变位姿下行星齿轮传动系统级动力学模型,并采用精细积分时程法（Precision integration method,PIM）求解得到了动态啮合力序列。根据齿间载荷分配关系进一步得到单齿啮合力序列。最后结合修正Heywood公式与Hertz公式构建了时变位姿下行星齿轮传动系统齿根弯曲动应力和接触动应力计算模型,并研究了机体平飞、滚转和筋斗位姿参数对接触动应力、弯曲动应力的影响规律。结果表明：不同时变位姿参数对弯曲、接触动应力影响显著,且对不同齿轮副影响不同,即加剧了齿轮副间承载不均;筋斗运动角速度对动应力影响比平飞加速度、滚转角速度以及筋斗回转半径对其影响复杂;机匣对动应力影响随加速度增大而增加。研究成果为时变位姿下行星齿轮传动动应力计算与高可靠性设计提供了理论依据。     

Quantitative damage detection for planetary gear sets based on physical models

Planetary gear set is the critical component in helicopter transmission train,and an important problem in condition monitoring and health management of planetary gear set is quantitative damage detection.In order to resolve this problem,an approach based on physical models is presented to detect damage quantitatively in planetary gear set.A particular emphasis is put on a feature generation and selection method,which is used for sun gear tooth breakage damage detection quantitatively in planetary gear box of helicopter transmission system.In this feature generation procedure,the pure torsional dynamical models of 2K-H planetary gear set is established for healthy case and sun gear tooth-breakage case.Then,a feature based on the spectrum of simulation signals of the dynamical models is generated.Aiming at selecting the best feature suitable for quantitative damage detection,a two-sample Z-test procedure is used to analyze the performance of features on damage evolution tracing.A feature named SR,which had better performance in tracking damage,is proposed to detect damage in planetary gear set.Meanwhile,the sun gear tooth-chipped seeded experiments with different severity are designed to validate the method above,and then the test vibration signal is picked up and used for damage detection.With the results of several experiments for quantitative damage detection,the feasibility and the effect of this approach are verified.The proposed method can supply an effective tool for degradation state identification in condition monitoring and health management of helicopter transmission system.     

一种CR-CR型自动变速器的运动分析和效率计算

以CR- CR双排行星齿轮机构四挡自动变速器为例,运用单排行星齿轮机构一般运动规律的特性方程式对该类变速器进行运动分析,采用啮合功率法将行星齿轮机构转化为定轴轮系机构,对自动变速箱的传动效率进行计算.所述方法为其进一步自动变速箱的结构改进和性能提高提供了一定的理论基础.     

Dynamic characteristics of a planetary gear system based on contact status of the tooth surface

Studies on the planetary gear have attracted considerable attention because of its advantages, such as compactness, large torque-to-weight ratio, vibrations, and high efficiency, which have resulted in its wide applications in industry, wind turbine, national defense, and aerospace fields. We have established a novel dynamic model of the planetary gear transmission by using Newton’s theory, in which some key factors such as time-variant meshing stiffness, phase relationships, and tooth contact characteristics are considered. The influences of gear axial tipping, operating conditions, and the meshing phase on the contact characteristics and the dynamic characteristics were researched systematically. It was found that the contact area of the tooth surface was moved due to the axial gear tipping, which obviously affected the meshing stiffness. With the increase in the inclination angle of the sun gear, the meshing stiffness decreases, which produces an evident influence on the high natural frequency in the planetary transmission system. In terms of the dynamic characteristics of the system, the component of rotating frequency appeared in the dynamic meshing force of the sun gear and the planetary gear. Moreover, the floating track of the center wheel varied significantly and exhibited an oval distribution as the inclination angle of the sun gear changed. When the inclination angle of the sun gear increased, the rotating frequency component increased significantly, but the other meshing frequency components remained unchanged; meanwhile, the deformation of the floating track also increased. If the inclination angle of the sun gear changes, the vibration state of the system and the collision impact could become more serious, and the lifetime of the planetary transmission system will reduce. Furthermore, when the load was increased, we found that the gear-tooth contact zone transformed from line contact to surface contact, the meshing stiffness increased, the effect of high natural frequency on the planetary transmission system became more evident, but its low-order natural frequency remained stable. With regard to the dynamic characteristics of the system, the components of the major frequency at the external gearing remained unchanged, but the rotation frequency of the sun gear and the meshing frequency amplitude increased linearly with the increase in load. In conclusion, the variation in the meshing stiffness of the planetary gear system had minor impact on the low-order natural frequency, but had a significant impact on the high natural frequency of the planetary transmission system due to the phase variation of the gear.     

考虑随机制造误差的风力机行星齿轮系统动力学特性

为研究综合传递误差的随机波动对风力发电机齿轮传动系统动力学特性的影响,考虑齿轮时变啮合刚度、综合传递误差等因素,建立风力发电机行星齿轮传动系统纯扭转动力学模型。以随机风速引起的齿轮系统转矩波动作为行星齿轮系统的外部激励,对某1.5 MW风力发电机行星齿轮传动系统的动力学特性进行仿真分析,得到系统各响应量时域内的统计特征和齿轮副间的动态啮合力统计特征。分析表明：行星架、行星轮和太阳轮在扭转方向上的振动特性与外部载荷相关,其振动位移与外部载荷波动有相似变化的趋势;综合传递误差随机分量的离散程度对行星齿轮系统的动态特性和齿轮副间的动态啮合力有较大影响。随着综合传递误差随机分量离散程度的增加,行星架、太阳轮和行星轮在扭转方向上的振动幅值明显增加;综合传递误差随机分量的随机性使齿轮副间动态啮合力产生随机波动,随机分量离散程度越大,动态啮合力波动越明显;当随机分量的离散程度达到某一值时,齿轮啮合过程发生脱离,引发啮合冲击。     

不同误差下风电齿轮箱均载与太阳轮轨迹关系研究

建立风电齿轮箱行星传动系统静力学模型,对比理论模型下的均载与实验下的均载,确定理论模型的正确性。将太阳轮、行星轮、内齿圈和行星架等构件的误差分为两类误差,以不同误差构件数量为基础,分别分析在两类误差作用下的均载与太阳轮轨迹中心方位角,并与综合误差作用下的均载与太阳轮轨迹中心方位角进行对比。建立了两类误差下的均载、综合误差下的均载与太阳轮轨迹中心方位角之间的关系,发现了太阳轮轨迹中心变化的平行四边形法则。此误差对行星传动系统均载的影响提供了新的研究思路。     

齿廓修形对齿面接触力影响的研究

简要介绍了齿廓修形的原理,给出了线性修形和二次曲线修形的表达式,利用齿轮分析软件建立了渐开线圆柱直齿轮的有限元接触分析模型,分析了修形前后齿间载荷分配及接触线上载荷分布情况,同时比较了不同修形量对修形后齿轮接触力分布的影响状况。本文能够为齿轮修形设计提供一定的理论依据。     

基于离散傅里叶变换与谐波平衡法的行星齿轮系统非线性动力学分析

研究了多间隙作用下行星齿轮系统的强非线性动力学行为。考虑齿轮啮合误差和时变啮合刚度,建立了2K—H型行星齿轮传动的弯扭耦合非线性动力学模型。利用离散Fourier变换(DFT)及其逆变换(IDFT)处理方程中非线性恢复力与位移坐标之间的函数关系,发展了一种可以求解多阶谐波响应的数值谐波平衡法,并用Broyden方法求解其形成的代数平衡方程组。用该方法分析齿轮非线性动力学稳态解时,啮合刚度与激励可以是任意的周期函数形式,不仅可以包含多次谐波响应,而且还可以求解系统的次谐波响应。克服了传统的解析谐波平衡法基于描述函数进行而难以求解一般周期响应和次谐波响应的缺点。作为算例,用该方法分析了行星齿轮传动的非线性频响特性,并与相应的线性系统进行了比较。     

Simulation and experimental test of load-sharing behavior of planetary gear train with flexible ring gear

Journal of Mechanical Science and Technology - For simulation and calculation of load-sharing behavior of planetary gear train by using the lumped mass method, an exact computational model of...     

行星齿轮传动提高工作平稳性的优化设计

以冲击振动理论为基础,以行星齿轮传动在工作中所受冲击动载荷和振幅最小为目托。在现有齿轮设计标准和规范的条件下,提出了行星齿轮传动优化设计的数学模型。实例计算结果表明,本文所述方法可行、有效。     

Planetary Gear Profile Modification Design Based on Load Sharing Modelling

In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this...     

少齿差内齿行星齿轮传动的研究现状

评述了少齿差内齿行星齿轮传动的研究现状、存在的问题和将来的研究方向。作为一种新型的齿轮传动机构,内齿行星齿轮减速器具有其自身的许多优点,但对其动力学性能的研究还不成熟。因此,需要在以下几个方面开展研究工作:符合实际的动力学特性研究、不平衡质量引起的动载问题、加工误差对其性能的影响等。     

轿车自动变速器机械传动方案研究

本文采用等效杠杆法分析了行星变速器的档位及传动方案,对轿车自动变速器机械传动方案的性能进行了分析比较。并对各国生产的轿车自动变速器机械传动方案进行归纳,寻找满足设计要求的各种可能方案,为国内自主开发自动变速器作准备     

行星齿轮传动变位参数的优化选择

为了提高NGW型行星齿轮传动的承载能力,本文对外啮合齿轮传动变位参数进行了二维优化设计,计算结果表明,合理选择变位参数可大大提高齿轮传动的承载能力.     

封闭行星齿轮传动系统的可靠性研究

通过对封闭行星齿轮传动系统进行运动学及力学分析，结合可靠性设计和Savage等提出的单级行星齿轮传动的可靠度模型，建立了以输入构件转速和转矩为变量的构件负载与寿命关系表达式；基于系统可靠度的乘积定律，建立了典型的封闭行星齿轮传动系统的可靠度模型；结合实例，研究了负载、有效齿宽、功率分配系数等因素对系统及其零件可靠性的影响。研究表明：系统的可靠度随着功率分配系数、负载的增大而减小，随着有效齿宽的减小而减小；合理地配置齿数可使传动系统获得较大的可靠度。     

Dynamic analysis and load-sharing characteristic of multiple pinion drives in tunnel boring machine

A dynamic model of multi-gear drive in a tunnel boring machine is demonstrated in this study in which the effects of inertia on the driving mechanism and cutter head are considered. With the nonlinear coupling factors between the ring gear and multiple pinions considered, a dynamic analysis of multiple pinion drives is conducted, and their load-sharing characteristic is proposed. The load-sharing coefficients at different rotating cutter head speeds and input torques are determined and are found to reach up to 1.2–1.3. A simulated experimental platform of multiple pinion drives is performed, and subsequent torque distributions are measured under step load in the driving shaft of pinions. An imbalance in torque distribution of pinions is verified, and the load-sharing coefficients in each pinion can reach 1.262. Torque load fluctuation is regarded as system noise that can directly be coupled into the control system in the control strategy.     

单级行星齿轮非线性动力学模型与试验验证

针对单排行星直齿轮传动系统,提出了齿轮非线性啮合动态模型,模型中考虑了由中心距安装误差和传动轴弯曲变形等引起的中心距变化对啮合角、间隙和非线性啮合刚度的影响。考虑中心距变化和陀螺力矩并结合齿轮非线性啮合动态模型,建立了行星齿轮传动系统横-扭耦合非线性动力学模型。针对一个单排行星齿轮传统系统试验装置进行仿真计算和试验测试,试验对比分析了齿圈横向振动位移和内啮合均载系数。研究结果表明,仿真结果与试验结果的变化趋势基本吻合,且误差在可接受范围内,验证了笔者提出的渐开线直齿轮传动横-扭耦合非线性动力学模型和非线性动态啮合模型的正确性。