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.     

少齿数差内啮合齿轮的强度计算

在少齿数差内啮合齿轮传动中存在多齿对同时啮合现象，使齿轮总载荷由各齿对分担，轮齿所承受的实际载荷会有较大幅度的降低，为此，提出在齿轮强度计算中引入载荷分配系数Kp的概念，通过所建立的数学模型，定量地确定了不同传动参数，不同载荷集度下，少齿数差内啮合齿轮传动的Kp值，并说明了在齿轮强度计算中应用该系数的方法。新的计算方法可以作为少齿数差内啮合齿轮强度计算的通用方法，以缩小传动装置的体积，避免齿轮强度存在过大裕量而造成浪费。     

三齿轮联动双曲柄四环板式针摆行星传动的动力学研究

在Pro/E软件系统下建立完整的三齿轮联动双曲柄四环板式针摆行星减速器虚拟装配实体模型,并基于ADAMS软件环境,对模型进行虚拟样机试验验证;建立了准确的动力学分析模型;完成了几种工况条件下虚拟样机的仿真计算;并结合样机工作性能与动力学测试,完成虚拟模型的实验室验证。     

基于 CAD的渐开线少齿差行星齿轮传动变位系数的选取

运用渐开线变位齿轮传动设计原理,建立了渐开线少齿差行星齿轮传动变位系数选择的约束模型,依据AutoCAD2000版本开发出了渐开线少齿差行星齿传动变位系数选择软件模块,从而大大提高了渐开线少齿差行星齿轮传动的设计效率和设计质量。     

Time-varying meshing stiffness calculation of an internal gear pair with small tooth number difference by considering the multi-tooth contact problem

Journal of Mechanical Science and Technology - Due to the multiple tooth contact problem involving internal gear pair with small tooth number difference (IGPSTND), the existing analytical methods...     

偏曲轴少齿差行星减速器优化设计

工程机械行业中,少齿差行星减速器具有较大的传动比、小的体积等优点,具有十分广泛的应用前景.因此,对少齿差行星传动机构进行优化设计及结构分析,具有重要的意义.本文基于遗传算法对偏曲轴少齿差行星传动机构进行设计,以期得到最优设计结构.     

多齿差摆线泵的流量特性分析及仿真

导出了多齿差摆线齿轮泵的瞬时流量、排量、平均流量和流量脉动的计算公式,分析了影响流量脉动的主要因素。结果表明,适当选择摆线齿轮的设计参数,可以减小流量脉动。并指出:采用优化设计方法来选择摆线齿轮的设计参数,可得到满足性能要求的设计结果。     

基于Matlab变齿厚偏曲轴少齿差传动变位系数计算研究

为了解决求解变齿厚偏曲轴少齿差减速器的变位系数过于繁琐问题,研究了变齿厚少齿差内啮合齿轮设计参数之间的关系,以及满足的限制条件。通过分析变齿厚内啮合齿轮的中心距、啮合角、变位系数之间的关系,提出了基于Matlab最小啮合角变齿厚内啮合齿轮变位系数遍历优化算法,并通过实例加以验证,分析了不同步长对计算结果的影响。指出该方法具有优化效率高、计算简单,避免其他优化方法的缺点。     

一种新型功率分流齿轮传动系统动态特性研究

平行轴转矩分流式齿轮传动在高速大功率传输系统中应用逐渐广泛,为了实现转矩的动态均衡,对某直升机旋翼驱动系统中的平行轴转矩分流式齿轮传动的动态特性进行了研究.首先用集中质量法建立了转矩分流式齿轮传动系统的8自由度动力学模型,然后采用牛顿法推导出了系统扭转振动微分方程,并使用模态分析法求解微分方程,求得了系统的固有模态与外激励响应.最后,研究了不同转速下各齿轮副的动载系数的变化规律,为动态均衡设计奠定了基础.     

基于ADAMS的新型滤波减速器的动力学分析

对新型滤波减速器的结构和工作原理进行了介绍,利用ADAMS软件建立了新型滤波减速器的虚拟样机,通过Step函数对虚拟样机定义运动和施加动静载荷并进行了运动仿真。仿真结果显示,滤波减速器的双联齿轮和输出齿轮的转速随时间的变化曲线与减速器的理论传动比相吻合,验证了虚拟样机的正确性;通过固定齿轮、双联齿轮啮合处y、z方向的啮合力的时域曲线图和频域曲线图,得出了滤波减速器的固有频率,为减速器的优化设计和工程分析提供依据.     

Model-based analysis and fault diagnosis of a compound planetary gear set with damaged sun gear

The vibration properties of compound planetary gears are more complicated than that of simple ones. This paper aims to investigate the fault properties of a compound planetary gear set in chipped sun gear conditions using model-based method. A three-dimensional lumped-parameter nonlinear dynamic model for the compound planetary gear set is established. This model considers the time-varying mesh stiffness (TVMS), the mesh phase relations, and gear chipping defects. The analytical equations are derived to quantify the TVMS reduction induced by the chipped gear based on the improved potential energy method. Further, the simulations are performed to demonstrate the fault features of sun gears with single or multiple chipped teeth in different gear stages. Moreover, the theoretical derivations are validated through the experimental signals analysis.     

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...     

基于MATLAB的二齿差滚柱活齿传动的廓线分析

用"等效机构法"推导了二齿差滚柱活齿传动的啮合曲线,提出了用矢量法求解激波凸轮和中心轮实际廓线的方法。运用MATLAB编程,计算了中心轮实际廓线的离散坐标点,生成IBL文件。分析了四种单参数修形方式与中心轮实际廓线曲率的关系,为中心轮齿廓修形提供了理论依据。     

基于初等数论方法的行星齿轮传动的装配条件分析

采用初等数论方法,推导并简化了双排行星齿轮传动可装配条件的配齿计算公式,提出了一种新颖的装配条件配 齿分析方法。     

行星轮点轨迹的图形特征与应用研究

通过行星轮上点的坐标的一至四阶导数在特殊位置上的零值关系,提出了规则图形与非规则图形的设计方法．给出了弧角近似直边正多边形、弧角、尖角或含结点角曲边正多边形、弧角近似直边正多角形、弧角曲边正多角形以及无限不循环图形的几何条件,指出了它们的应用领域。     

圆锥齿轮轮齿变形及测试装置研究

本文以当量齿形对圆锥齿轮轮齿变形进行了编程分析计算,而且首次提出了适于直、斜齿圆锥齿轮轮齿变形实测实验台,经仿真与理论计算吻合。     

一种用于折叠翼飞机的行星齿轮机构动力学分析

针对折叠翼飞机的折叠机构,在齿轮啮合机构基础上提出一种行星齿轮传动机构实现机翼折叠,利用ADAMS软件对两种机构进行了动力学仿真分析.通过对两种机构的对比分析,证明针对折叠翼飞机设计的行星齿轮机构较原齿轮啮合机构能够有效减小齿轮间的接触力,改善机构的运动平稳特性,降低对驱动电机转矩的要求,有利于提高机构的效率.经仿真分析,证明所设计的行星齿轮传动机构可作为折叠翼飞机的折叠传动机构方案.     

Vibration signal modeling of a planetary gear set with transmission path effect analysis

For a planetary gear set, the transducer-perceived vibration signal contains vibration information from multiple sources including the sun gear, planet gears, and the ring gear. All these vibration sources are subject to corresponding transmission path effects. In this paper, a comprehensive vibration signal model for a planetary gear set is proposed considering all the vibration sources and transmission path effects. Vibration sources were generated with a nonlinear two-dimensional lumped-parameter dynamic model. Transmission path effects are modeled as two parts: the part inside the gearbox to the casing and the other part along the casing to the transducer position. Given the gear sizes, the transmission path effect modeling parameters are estimated. Then the influences of different transmission paths on resultant vibration signals are analyzed. Some vibration characteristics are revealed for one healthy planetary gear set. These vibration characteristics are validated with lab experimental data in both time domain and frequency domain.     

塑料行星齿轮系统振动与噪声特性的研究

为了进一步了解塑料行星齿轮传动系统的传动特性,建立了塑料行星齿轮传动系统的物理模型和实验模型.对塑料行星齿轮传动在不同工况下的振动特性及噪声特性进行了研究.研究结果表明:塑料行星齿轮传动的振动主要分布在齿轮啮合基频带及各次倍频、谐频带和转子不平衡频带等;转速和负载的增大加剧了塑料行星齿轮在啮合基频处和谐频处的振动强度;负载的增加会抑制塑料行星齿轮在啮合2倍频处的振动强度;负载和转速的增加会明显的抑制转子不平衡的影响;噪声随着转速的增大而增大,负载的增大会抑制噪声的强度,噪声的峰值与各频带的共振峰值有着对应的关系.     

爬壁机器人的力学分析与实验

运用键图理论建立了爬壁机器人负压吸附动力学过程模型,并对其进行了仿真及实验分析.针对爬壁机器人的特点,对负压吸附系统的技术要求进行了详细分析,设计了高效率负压吸附系统.在对负压吸附系统进行合理的假设和流体力学分析的基础上,运用键图理论针对不同物理域具有参数等效的特点,把负压吸附流体系统参数等效为机械动力学中的力、位移、刚度和阻尼;负压吸附动力学模型等效为一阶的机械系统,建立了键图模型,应用20sim软件进行仿真.仿真结果显示,爬壁机器人负压吸附过程在负压形成过程中是一阶响应过程,系统响应时间为1.5 s.最后进行了试验测试,测试结果证明了所建立模型的正确性.