支撑变形下弧齿锥齿轮传动的承载接触有限元分析

转子的变形会对弧齿锥齿轮传动的接触轨迹及传动误差产生影响,从而影响传动的平稳性和可靠性。在传动系统弯扭耦合振动分析的基础上,获得弧齿锥齿轮的支撑变形量,并将其等效为齿轮副的安装错位量。基于加载接触有限元分析原理,利用MATLAB自编有限元程序,给出了考虑支撑变形的弧齿锥齿轮承载接触分析方法。以一对弧齿锥齿轮为对象,研究其在一个啮合周期内小齿轮齿面最大接触应力和齿根最大弯曲应力的变化情况,为高质量弧齿锥齿轮传动提供了一种有效的设计与分析方法。     

弧齿锥齿轮传动系统动态特性研究

基于集中质量法建立了弧齿锥齿轮8自由度弯-轴-扭三维空间动力学模型.模型中考虑了啮合刚度的时变性、几何传递误差的非线性、齿轮副间隙及轴承刚度的非线性.利用齿面接触分析与齿面承载接触分析求出几何传递误差与轮齿综合啮合刚度,利用轴承变形理论求出系统非线性支承刚度,使用Runge-Kutta法对传动系统进行动态响应求解,并研究了这些因素对弧齿锥齿轮振动的影响.结果表明:几何传递误差是影响齿轮振动的最主要因素,由啮合刚度变化引起的一系列振动受转速与负载的影响较大.     

弧齿锥齿轮加载啮合特性有限元分析

基于齿轮啮合原理计算获得了弧齿锥齿轮精确的三维几何实体模型,并由此建立了齿轮加载啮合特性有限元分析模型,以赫兹接触解析法合理地确定了有限元的网格密度。根据弧齿锥齿轮副6齿对模型,获得了齿轮在啮合过程中的齿面接触应力和齿根弯曲应力最大值的位置,并绘制出了啮合周期内的应力曲线。分别以载荷和安装误差参数为变量,研究了弧齿锥齿轮加载情况下的接触斑点以及接触轨迹等啮合特性。研究结果对弧齿锥齿轮的设计和实际应用起到了重要的指导作用。     

加载螺旋锥齿轮接触轨迹变化规律的研究

螺旋锥齿轮的接触轨迹直接反映传动质量,基于加载接触有限元分析原理,给出螺旋锥齿轮有限元加载接触分析模型的构建方法,取一对三齿螺旋锥齿轮模型,研究在轻载和重载情况下轮齿的接触力变化情况,得到载荷对接触轨迹及传动误差的影响规律,为高质量弧齿锥齿轮传动提供了一种设计方法与手段。     

一种弧齿锥齿轮时变啮合刚度和传动误差半解析计算方法

弧齿锥齿轮时变啮合刚度传统计算方法大多采用有限元静态分析方法,但需计算多次,且采用节点弹性变形平均值计算的单齿啮合刚度存在较大误差。为此,改进了弧齿锥齿轮时变啮合刚度计算方法,在传统计算方法上引入单个节点啮合刚度,将工作齿面各个节点啮合刚度叠加,得到单齿啮合刚度,计算精度更高;基于有限元显式动态分析计算弧齿锥齿轮时变啮合刚度和传动误差,计算1次而不需要进行多次有限元分析,减少了整个计算时间周期。研究了不同负载转矩下时变啮合刚度和传动误差变化规律,分析了接触椭圆长轴长度、接触轨迹方向两个接触参数对时变啮合刚度和传动误差的影响。研究结果表明,时变啮合刚度和传动误差随负载转矩增大而增大,但时变啮合刚度峰-峰值和传动误差峰-峰值(PPTE)随负载转矩增大而变小;随着接触椭圆长轴长度增大,时变啮合刚度和传动误差呈增大趋势;随着接触轨迹方向增大,时变啮合刚度存在突增现象,而传动误差变化很小。     

弧齿锥齿轮接触特性的概率分析

弧齿锥齿轮齿面接触特性受到传动系统中许多随机因素的影响,概率分析可对齿面接触中的随机特性进行量化描述。本文针对某航空发动机弧齿锥齿轮传动系统,将传递功率、转速、转子不平衡量及支承刚度等作为基本随机变量,通过对系统进行动态概率计算,获得了齿轮安装基点变形的统计规律。将概率分析引入齿面接触分析技术中,研究了在齿轮安装基点随机变化过程中齿面接触域和传动误差的概率特性,计算了齿面稳定接触的可靠性。     

安装误差对弧齿锥齿轮啮合性能影响的有限元分析

以一对弧齿锥齿轮为例分析了各类安装误差对接触应力和接触路径的影响,依据局部综合法设计得到了齿轮副加工参数,求得齿轮齿面并以此建立有限元模型。通过涉及安装误差的几何接触分析,完成一对齿轮的装配,避免手动装配造成的误差。对有限元模型进行轮齿接触分析,得到齿轮在不同安装误差下的有限元计算结果。利用有限元软件的后处理功能,编写Python程序提取不同安装误差下齿轮的接触应力曲线及接触路径。结果表明:轴向安装误差对齿轮的啮合性能影响较大,而轴交角误差和偏置距误差对其影响较小。     

功率分流四分支轮系建模与承载特性分析

为了准确得到弹性支撑下功率分流四分支轮系的承载特性,建立其力学结构模型,推导出变形协调条件。考虑中心距安装误差、轴交角误差、轴承弹性支撑刚度对轮齿接触轨迹及传递误差曲线的影响会导致时变啮合刚度曲线的变化,进而在轮齿承载接触法的基础上分析了弹性支撑下各误差存在时功率分配的情况。结果表明,弹性支撑刚度条件会导致仿真结果差异较大,弹性支承更符合实际。为四分支传动系统的设计与分析提供参考。     

弧齿锥齿轮加工三维数字化动态仿真研究

弧齿锥齿轮用来传递相交轴之间的回转运动,由于具有重合度大、传动平稳、承载能力高等优点,广泛应用于车辆、航空航天飞行器、工程机械、机床等。弧齿锥齿轮的几何特性与啮合过程非常复杂,机床结构和加工调整也很困难,同时加工刀具、机床调整、加载变形和装配误差等各种因素的改变     

重载弧齿锥齿轮承载特性分析

基于啮合原理和SGM切齿计算方法获取了真实的弧齿锥齿轮齿面点数据,建立了精确的几何模型。采用加载接触分析的方法,建立了重载弧齿锥齿轮的承载特性有限元分析模型。以工况参数和安装误差为变量,研究了弧齿锥齿轮受载情况下的接触区、齿间载荷分配和强度等承载特性。为研究有安装误差和重载工况下的弧齿锥齿轮承载特性提供了一种有效的分析手段。     

Effects of dynamic transmission errors and vibration stability in helical gears

Transmission error is an important reason for instability in helical gears. A six-degree-of-freedom dynamic model coupled flexional, torsional and axial motion of a helical gear transmission system, which includes time varying mesh stiffness, bearing supporting stiffness, mesh damping and backlash, is developed, after taking into account the dynamic characteristics and vibration responses of helical gear in three dimensions. Influences of involute contact ratio, bearing supporting stiffness, mesh damping and backlash on the dynamic transmission errors and vibration stability of the helical gear system are investigated using numerical simulation technique. The effects on dynamic transmission errors and stabilities by contact ratio, supporting stiffness and mesh damping as well as gear backlash are analyzed. The intrinsic relationship between above parameters and dynamic transmission errors and stabilities for helical gear system are presented. The stable and unstable regions under different parameters are given. The results in this paper can be helpful to the dynamic and stable design of a helical gear transmission system.     

波箔片制造误差对径向波箔轴承静刚度的影响

为探究制造误差对径向波箔轴承的影响,基于Timoshenko梁单元建立波箔片变形的简化模型,基于ABAQUS建立波箔片的实体模型,并对比2种模型下波箔片的静刚度。结果显示,Timoshenko梁模型和实体模型的波箔片静刚度曲线较为吻合,且均呈线性变化。建立径向波箔轴承的实体模型,对轴颈进行位移加载,分析轴承的静刚度特性。结果显示,在考虑摩擦时,轴承的静刚度存在明显的滞回特性。设计存在2种不同误差类型的径向波箔轴承,并对其静刚度特性进行分析,发现波高误差对静刚度的影响大于波距误差,且控制起主要支承作用的波纹的波高误差能够有效降低制造误差对径向波箔轴承静刚度的影响。     

基于差齿面拓扑的轮齿承载拟赫兹接触分析

基于齿条曲面多项式与齿轮公切共轭产形原理,建立了数值齿面、差齿面ease-off模型;通过ease-off曲面映射,解析了齿面接触路径、传动误差、接触线等轮齿啮合特性信息。利用势能法、变形协调方程与拟赫兹接触分析解决了齿面载荷计算、边缘接触应力求解问题,获得了轮齿啮合刚度、传动误差、齿间载荷分担、载荷分布、接触应力等齿面啮合的时变历程特性。计算结果与第三方软件的计算结果具有较好的一致性。     

Thermo-mechanical analysis of angular contact ball bearing

The thermal-mechanical character, which is difficult to ensure because of the lack of a corresponding theory and tool, has a significant effect on the dynamics of bearings. It even leads to a sudden failure of bearings in a working situation. In this research, a thermal deformation model was established, based on the analysis of temperature effect on the basic size of angular contact ball bearing. And the transmission from rolling size to bearing axial stiffness was explicit. On the basis of the variation of Hertz contact stiffness and the change of initial contact angle of angular contact ball bearing caused by temperature rise, a “Thermo- mechanical” model of bearing was proposed. According to this model, using the corresponding calculation procedure programmed by MATLAB, the effect of bearing temperature on the axial stiffness has been studied. And the correctness of this model was verified with experiments. Some design suggestions have been made for the decision of bearing preload: to prevent the bearing failure caused by overheating.     

Localised tooth contact analysis of single envelope worm gears with assembly errors

This paper presents the basis of loaded tooth contact analysis and predicts the influence of assembly errors on localised contact stress distribution in single enveloping (cylindrical) worm gearing during a meshing cycle. A method for loaded tooth contact analysis, geometry and kinematics of such gear pairs is developed. The method accounts for the effects of tooth composite deflection caused by bending, shearing, foundation, tooth contact deformation and initial profile separation due to assembly errors. The method includes the determination of contact lines, load and stress distribution due to assembly errors. Because of the complex geometry of worm gear teeth, the tooth bending stiffness is calculated using the slicing technique developed earlier by the authors. Classical Hertz theory is used for calculating contact stress and deformation. A computer program based on the presented method has been developed and used to study the influence of errors on mating teeth contact. It is shown that the governing factors in loaded gears with assembly error are the mesh stiffness and the amount of error which is linked to load sharing between adjacent tooth pairs. A numerical example is presented to further clarify the outlined method.     

Quasi-Static and Dynamic Behaviors of Helical Gear System with Manufacturing Errors

Time?varying mesh stiffness(TVMS) and gear errors include short?term and long?term components are the two main internal dynamic excitations for gear transmission. The coupling relationship between the two factors is usually neglected in the traditional quasi-static and dynamic behaviors analysis of gear system. This paper investigates the influence of short?term and long?term components of manufacturing errors on quasi?static and dynamic behaviors of helical gear system considering the coupling relationship between TVMS and gear errors. The TVMS, loaded static transmission error(LSTE) and loaded composite mesh error(LCMS) are determined using an improved loaded tooth contact analysis(LTCA) model. Considering the structure of shaft, as well as the direction of power flow and bearing location, a precise generalized finite element dynamic model of helical gear system is developed, and the dynamic responses of the system are obtained by numerical integration method. The results suggest that lighter loading conditions result in smaller mesh stiffness and stronger vibration, and the corresponding resonance speeds of the system become lower. Long?term components of manufacturing errors lead to the appearance of sideband frequency components in frequency spectrum of dynamic responses. The sideband frequency components are predominant under light loading conditions. With the increase of output torque, the mesh frequency and its harmonics components tend to be enhanced relative to sideband frequency components. This study can provide effective reference for low noise design of gear transmission.     

输入转矩对驱动桥系统动力学特性的影响

在驱动桥系统中,滚子轴承是连接轴系与壳体的关键部件,其刚度具有各向耦合性和非线性特性,且与输入转矩有关。为准确高效地分析输入转矩对驱动桥系统动力学特性的影响,基于非线性轴承理论、有限元法和模态综合方法,建立包含主减速器总成、差速器总成、轮毂总成和桥壳等部件的完整驱动桥系统动力学分析模型,根据输入转矩大小的不同,定义轻载、中载和重载三种典型工况,分别计算各工况下的非线性轴承刚度,分析轴承刚度随输入转矩大小变化的特点,对驱动桥系统进行单位谐波传动误差激励下的动力学分析,研究输入转矩对驱动桥系统动力学特性的影响,分析不同工况下准双曲面齿轮动态啮合力的频响特性。计算结果表明,驱动桥系统动力学特性随输入转矩大小变化具有一定规律,能有效指导驱动桥系统的减振降噪设计,避开危险工况。     

Undercutting and contact characteristics of longitudinal cycloidal spur gears generated by the dual face-hobbing method

This paper investigated the undercutting of longitudinal cycloidal spur gear generated by the dual face-hobbing method. Sensitivity of transmission errors and contact patterns due to varied assembly errors were studied using the tooth contact analysis (TCA) technique. The undercut of the longitudinal cycloidal spur gear is similar to the regular spur gear except for the fact that the helical angle is varied along the longitudinal direction due to the cycloidal cutting trace. Several numerical examples are presented to validate the derived undercutting of the proposed longitudinal cycloidal spur gear and the tooth contact pattern sensitivity. As expected, the bearing contact and transmission error are insensitive to the assembly error.     

轴线不平行度对人字齿轮齿面啮合性能的影响分析

人字齿轮传动由于加工安装误差、轴承支撑布置无法对称等条件,不可避免会产生轴线的微量不平行。因人字齿轮齿宽较大、啮合刚度高、标准渐开线齿面线接触等特点,微量的轴线不平行度就会导致严重的齿面偏载,影响齿轮传动的平稳性和可靠性。因此,采用了小轮较大轴向浮动的轴承支撑结构,并研究了小轮轴向浮动的人字齿轮齿面承载接触仿真(LTCA)方法,通过大、小轮轴向固定和小轮轴向浮动两种不同轴承支撑结构的仿真比较,说明小轮轴向自位浮动可以有效改善齿面偏载,为人字齿轮传动系统的设计提供了参考。     

2K-V型传动装置制造误差对传动精度的影响

以2K-V型减速机为研究对象,综合考虑各零件加工误差、装配误差、齿轮啮合间隙、轴承间隙、零件弹性变形及其旋转零件的惯性载荷等因素对传动精度的影响,建立了非线性动力学计算模型;并利用该模型对传动装置中各零件的加工误差、装配误差所引起的系统回转传动误差进行研究,进而从诸多误差种类中找出对传动精度影响较大的主要误差种类。该研究结果对设计、制造高精度2K-V型传动装置具有重要的指导意义。