齿轮传动中磨损问题的研究及修复方法综述

齿轮传动是机器传递运动和动力的一种主要形式。如何减少齿轮工作中的磨损、延长其使用寿命是工业生产中至关重要的问题.总结了齿轮磨损问题的基本类型、研究历程、研究方法以及失效齿轮的常用修复方法等.     

Acetal gear wear and performance prediction under unlubricated running condition

Tests have shown that the acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry. The gear surface will wear slowly with a low specific wear rate if the gear is loaded below the critical condition. The sudden increase in wear rate may be due to the gear operating temperature reaching the material melting point under the critical load condition. Gear surface temperature has been investigated in detail by studying three components: ambient, bulk and flash temperatures. Through extensive experimental investigations and modelling on gear surface temperature variations, a general relation has been built up between gear surface temperature and gear load capacity. A new design method for acetal gear has been proposed based on the link between polymer gear wear rate and its surface temperature. The method has been related to test results under different operating ambient temperature and gear geometries. Good agreements have been achieved between the proposed method predictions and experimental test results. The maximum torque the acetal gears can transmit is 9 Nm for both the driver and driven with a 2 mm module, 30 teeth and 17 mm face width. Copyright © 2006 John Wiley & Sons, Ltd.     

一种面齿轮传动时变啮合刚度数值计算方法

准确计算时变啮合刚度是齿轮动力学研究的基础。提出了一种面齿轮传动时变啮合刚度数值计算新方法。以直齿圆柱齿轮为例,建立合理的有限元模型,得到直齿圆柱齿轮的时变啮合刚度曲线,并将其与ISO6336方法计算结果进行对比,验证了该啮合刚度计算方法的正确性及有限元模型的精确性。应用该数值计算方法,研究面齿轮传动时变啮合刚度变化规律,得到了精确的面齿轮传动时变啮合刚度曲线。研究结果为面齿轮传动的动力学分析及设计提供参考。     

直齿锥齿轮齿廓修形

根据啮合刚度和噪声之间的关系,以修形减振降噪为目的,用旋转渐开线曲线对直齿锥齿轮进行齿廓修形.以减小齿轮传动误差和啮合刚度的波动大小为衡量标准,同时确保载荷变化呈平稳过渡.静态计算结果表明,直齿锥齿轮齿廓长修形具有较好的减振效果.直齿锥齿轮采用冷精锻进行齿廓修形,显著地降低了成本,这为齿轮传动系统的修形、减振、降噪和设计提供了一种新的研究方法.     

齿面摩擦和啮合刚度对双渐开线齿轮传动动态特性的影响研究

针对双渐开线齿轮传动动态特性问题,通过建立双渐开线齿轮的有限元模型,综合考虑齿面摩擦与齿轮啮合刚度二因素,对双渐开线齿轮传动系统进行了有限元模态分析,运用响应曲面法研究了齿面摩擦与齿轮啮合刚度对双渐开线齿轮振动变形和模态频率的影响;选取不同模态阶数对双渐开线齿轮传动系统进行了动态特性研究,分析了不同模态阶数下双渐开线齿轮的振动变形与模态频率变化状况。研究结果表明,随着齿面摩擦因数与齿轮啮合刚度的增加,不同模态阶数下双渐开线齿轮传动系统各阶振动变形与模态频率均显著增加,齿面摩擦与齿轮啮合刚度对双渐开线齿轮传动动态特性有一定影响,在对齿轮传动系统进行动态特性研究时,必须对齿面摩擦与齿轮啮合刚度进行充分考虑。     

液压转向器动态特性的建模与仿真分析

以全液压同轴流量放大器为对象,建立了动态特性数学模型。分析了其稳定性和动态性能,得到了放大器输入阶跃转角与输出流量和放大器输入阶跃转速与输出流量之间的仿真曲线。结果表明,该转向器具有较快的响应速度,在阶跃输入作用下,其输出仅需0．06s即可达到峰值,0．28。即可完成过渡过程,完全可满足车辆对转向速度的要求。     

齿轮时变系统的强迫振动

建立了考虑齿轮时变啮合刚度时的二级齿轮系统的动力学模型，用A算符方法推导出了系统的近似解析解，研究了系统对时变啮合刚度、扭矩波动及齿轮误差激励的响应。计算结果表明，A算符方法克服了谐波平衡法的缺陷，可靠性更高；系统响应的频率成分不仅与啮合频率和激励频率有关，还与其组合形式有关；即使激励频率远大于派生系统的固有频率，在实际的物理系统中，由于时变啮合刚度的影响，也可能出现主共振、谐共振和组合共振。     

变位渐开线齿轮的特征参数化建模研究

文中讨论了由齿条型刀具范成法加工的变位渐开线齿轮的特征参数化建模技术,该技术实现了较精确的齿轮CAD模型,并可通过改变刀具或齿轮的齿形参数自动生成齿轮三维模型,为齿轮的CAE/CAM精细化研究打下了基础.     

振动与齿轮副基本动态特征间的关系

在考虑齿轮系统振动运动的基础上,建立了齿轮副实际中心线和两基圆内公切线运动方程,分析论证了实际中心线和两基圆内公切线的运动特征及实际啮合线的形态.并指出,由于系统振动的原因,齿轮副的实际中心线和两基圆内公切线是随时间的延续以平面运动方式变化的,实际啮合点的轨迹是一条曲线;同时,系统振动还使啮合齿对提前或迟后进入啮合、提前或滞后退出啮合.     

齿轮三维建模方法的误差分析

对齿轮的各种建模方法进行了对比分析,提出一种较为精确、可行的建模方法,对各种建模方法的误差及其对齿轮运动精度的影响进行了探索和对比分析,并就如何在虚拟环境中对虚拟的齿轮进行精度检测,提出一种尝试。     

An analysis of the wear features of worm gear tooth flanks

Worm reducers with a double enveloping toroidal surface are a new type of reducer with higher wear resistance and longer service life. A series of contact fatigue tests of worm pairs has been carried out on a microcomputer-controlled test stand of closed power flow type, using an incremental method of increasing the load. During the test, the worm tooth flank completed 2.2 × 10⁷ cycles, and the worm gear tooth flank 1.1 × 10⁶ cycles. Meanwhile, the state of the flank was duplicated by means of a chemical film. This paper discusses the whole process of the occurrence and development of surface cracks as well as the formation of fatigue peeling. It should provide a reliable basis for definition of the law of fatigue damage of the worm gear tooth flank.     

基于有限元法的直齿圆柱齿轮振动模态分析

主要研究直齿圆柱齿轮的固有振动特性,利用ANSYS有限元软件建立直齿圆柱齿轮的三维模型并对其进行动力学模态分析,通过求解分析得到齿轮的低阶固有频率、主振型以及相对位移和相对应力,为齿轮及其系统的动态设计提供参考依据。     

Experimental studies on the effects of reduction in gear tooth stiffness and lubricant film thickness in a spur geared system

Gears are one of the most common mechanisms for transmitting power and motion and their usage can be found in numerous applications. Studies on gear teeth contacts have been considered as one of the most complicated applications in tribology. Depending on the application, the speed and load conditions of teeth may change triggering several types of failures on teeth surface such as wear, scuffing, micro-pitting and pitting. The above-mentioned faults influence changes in vibration and acoustic signals, due to changes in operating conditions such as increase in temperature and decrease in lubricant film thickness and specific film thickness. These abnormal changes result in cumulative effects on localised or distributed faults on load bearing surfaces of gears. Such damages cause reduction in tooth stiffness and severity of damage can be assessed by evaluating the same using vibration-based signals.This paper presents the results of experimental investigations carried out to assess wear in spur gears of back-to-back gearbox under accelerated test conditions. The studies considered the estimation of operating conditions such as film thickness and their effects on the fault growth on teeth surface. Modal testing experiments have been carried out on the same gear starting from healthy to worn out conditions to quantify wear damage. The results provide a good understanding of dependent roles of gearbox operating conditions and vibration parameters as measures for effective assessment of wear in spur gears.     

直齿圆柱齿轮的虚拟设计与分析

利用Pro/E程序本身的参数化功能实现了渐开线直齿圆柱齿轮的三维造型,同时应用其内在的Mechanica模块对建立的参数化模型进行仿真和有限元分析,从而生成应力、应变条纹图,运行结果验证了应用Pro/E软件进行虚拟设计的可行性和分析研究的正确性,并提高了设计研究的效率。     

Dynamic analysis of involute spur gears with asymmetric teeth

New gear designs are needed because of the increasing performance requirements, such as high load capacity, high endurance, low cost, long life, and high speed. In some applications, such as in wind turbines, the gears experience only uni-directional loading. In these instances, the geometry of the drive side does not have to be symmetric to the coast side. This allows for the designing of gears with asymmetric teeth. In previous studies related to bending stress and load capacity, high performance has been achieved for gears with asymmetric teeth. These gears provide flexibility to designers due to their non-standard design. If they are correctly designed, they can make important contributions to the improvement of designs in aerospace industry, automobile industry, and wind turbine industry. At high operation speeds, there is always a concern of dynamic loads and vibrations of equipment. Therefore, there is a need to fully understand the dynamic behavior of gears with asymmetric teeth. Thus, the primary objective of this paper is to use dynamic analysis to compare conventional spur gears with symmetric teeth and spur gears with asymmetric teeth. The secondary objective is to optimize the asymmetric tooth design in order to minimize dynamic loads. This study offers preliminary results to designers for understanding dynamic behavior of spur gears with asymmetric teeth. For this study, a dynamic model was developed, using MATLAB, and used for the prediction of the instantaneous dynamic loads of spur gears with symmetric and asymmetric teeth. Furthermore, a 2-D three-tooth model was developed for finite element analysis. Fast Fourier transform was used for the frequency analysis of the static transmission errors. It is shown that generally, the dynamic factor, for spur gears with asymmetric teeth, increases with increasing pressure angles on the drive side. For asymmetric teeth, increasing the addendum leads to a significant decrease in the dynamic factor. The static transmission error, at the center of the single tooth contact zone, decreases with increasing pressure angle. The first two harmonics slightly increase with increasing pressure angle. It is further shown that the amplitudes of harmonics of the static transmission errors are significantly reduced when asymmetric teeth with long addendum providing high gear contact ratio close to 2.0 are used.     

齿轮箱中齿轮故障的振动分析与诊断

首先建立了齿轮箱中轴承无故障、齿轮有故障时齿轮箱振动信号的理论模型,介绍了齿轮箱中齿轮故障诊断的高频共振方法,阐述了该诊断方法的信号处理和诊断流程,并对该诊断方法的使用效果进行了实际验证.应用结果表明,该诊断方法能有效地诊断齿轮箱中齿轮的局部损伤故障.     

闭式齿轮传动系统内部动态响应的有限元法预测

针对闭式齿轮传动系统动态分析理论求解复杂,试验方法只能测得表面振动数据的问题,对某二级行星减速器进行三维建模生成有限元模型,完成有限元模态分析;通过模态试验,验证了模拟的正确性;利用ANSYS瞬态动力学分析的完全法(full),考虑时变啮合刚度、综合啮合误差、齿侧间隙及阻尼比等非线性因素的影响,实现了动态模拟和台架试验对比.研究结果表明:有限元法所得前六阶固有频率与试验结果接近,频率最大误差为8.12％,振型吻合;动态模拟结果与台架试验测得的振动加速度平均值误差较小,振动规律基本一致.以此为依据,获取了输入端与输出端的振动加速度和齿圈啮合点应力变化曲线,与工程实际相符,有限元预测方法可弥补试验法在分析内部振动响应方面的不足.     

考虑磨损与变形的谐波齿轮精度可靠性分析与优化设计

针对谐波齿轮减速器中存在的磨损和变形因素导致减速器传动精度低、可靠性差等问题,建立考虑磨损与变形的谐波齿轮减速器传动误差模型,并进行精度可靠性分析与优化设计。通过分析传动误差的影响因素建立了传动误差模型;基于磨损经验模型和试验数据,应用贝叶斯修正方法建立动态磨损模型,同时根据试验数据和高斯过程回归建立柔轮变形模型;综合获得的传动误差模型、磨损模型和柔轮变形模型建立谐波齿轮精度可靠性模型,并应用基于拉丁超立方抽样的Kriging代理模型和蒙特卡洛法求解某谐波齿轮减速器传动精度可靠度。最后采用序列二次规划法对谐波齿轮减速器进行优化设计。优化结果表明,在工况参数(输出端负载17.5 N·m,输入端转速100 r/min)下,优化后的谐波齿轮减速器在工作时间3 000 h处的可靠度达到99.02%,相比未优化前提升7.85%,而成本却只增加1.70%。     

考虑齿距偏差的直齿轮转子系统振动特性分析

针对工程实际中的齿轮存在齿距偏差,主要研究齿距偏差对齿轮系统振动特性的影响。考虑齿距偏差,建立了齿轮啮合刚度和传递误差模型,在此基础上,建立了通用齿轮啮合动力学模型,将该模型与转子系统有限元模型进行耦合,得到了齿轮转子系统有限元模型,分析了齿距偏差对系统振动响应的影响。研究结果表明:由于齿距偏差的存在,齿轮双齿啮合区刚度降低,无载荷传递误差增大,齿轮系统振动增大,频谱图中出现啮合频率及其高次谐波的边频带成分,这些边频带主要由主动和从动齿轮的转频及其倍频组成。减小齿距偏差和增大作用扭矩均能降低齿距偏差引起的边频带幅值。研究结果可为含齿距偏差的齿轮振动分析提供理论依据。     

基于直廓内齿轮的行星轮系传动误差分析

直廓内齿轮代替渐开线内齿轮在加工精度、加工效率和加工成本上都有独特的优势,并且已在试验中得以证明.由于直廓内齿轮的行星轮系是多对齿轮副啮合,既有太阳轮与行星轮的渐开线齿轮副,又有行星轮与内齿轮的非渐开线齿轮副.因此,轮齿接触分析(Tooth Contact Analysis,TCA)中必然存在传动误差(Transmission Error,TE).文中通过建立系统中产生传动误差的齿轮副啮合模型,给出基于直廓内齿轮行星轮系传动误差的求解方法.最后,在多体动力学仿真软件Recurdyn中建立了行星轮系的刚柔耦合动力学模型,进行轮齿承载接触分析(Loaded Tooth Contact Analysis,LTCA).