Reducing the vibration of a chevron gear transmission

A mathematical model is proposed for tooth vibrations in chevron gear transmissions. Methods of reducing the vibrations in spiral engagement are outlined.     

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.     

履带车辆齿轮传动系统非线性振动特性研究

以齿轮系统动力学和非线性振动理论为基础,针对具有齿侧间隙和时变啮合刚度的某履带车辆齿轮传动系统,建立单自由度齿轮系统非线性振动模型,通过数值仿真方法求解并分析在不同档位下的振动特性,并对其在某些变量参数下进行了振动特性研究,所得结果既反映了动力学性能,又为下一步进行多自由度齿轮系统的非线性振动研究提供了有力的依据.     

液力传动变速箱内啮合齿轮泵的早期磨损分析及改进设计

搬运车辆传动系统的液力变速箱由于受到外形空间尺寸和结构的严格限制,经常采用内啮合齿轮泵。啮合齿轮泵是液力变速箱控制操作的动力源,关键的核心部件之一,其工作状态决定了车辆的行驶性能、操作性能的优劣。     

粉末冶金斜齿轮系统振动频率响应分析

利用有限元法建立包含齿轮副、传动轴、轴承和箱体的齿轮系统完整的动力学模型。使用有限元分析软件 MSC.Nastran计算了在齿轮动态激励下粉末冶金斜齿轮系统的振动响应,并与38CrMoAl刚性齿轮系统进行比较。     

齿轮变位对传动振动的影响

本文就齿轮变位对传动振动的影响作了分析，探讨了通过选择适当的变位形式与变位系数降低传动振动的方法。同时还作了模型试验，试验结果与理论分析结果基本吻合。     

同步带传动系统横向振动的分析研究

建立了同步带传动横向振动的运动方程式，导出了静态时（带的运动速度为零）同步带横向振动的目振频率，并对同步带在运动时横向振动的自振频率进行了修正。     

Polymer gear surface thermal wear and its performance prediction

This paper will concentrate on acetal gear wear behaviour and its performance prediction based on the extensive investigations on the gear thermal mechanical contact both experimentally and numerically. It has been found from the tests that acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry and running speed. The gear surface will wear slowly with a low specific wear rate if the gear is loaded below the critical one. The possible reason of the sudden increase in wear rate is due to the gear operating temperature reaching the material melting point under the critical load condition. Gear surface temperature has been then investigated in details through 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. An approach for acetal gear transition torque prediction has been proposed and this method is based on the link between polymer gear wear rate and its surface temperature. The method has been related to test results under different operating speeds and gear geometries. Good agreements have been achieved between the proposed method predictions and experimental test results.     

The effects of friction-induced vibration on friction and wear

Friction tests were carried out with an elastic system where the specimen was supported by the elastic plate spring with strain gauges and with a rigid system where the vibration of the specimen was restricted. The coefficient of friction was obtained by two different methods: a deflection method with an assembly that consisted of a spring and strain gauges and an inertia method with a flywheel. The friction and wear properties of steel-steel, white metal-steel, phosphor bronze-steel and bronze-steel pairs were examined. When the frictional operation was conducted in the elastic system accompanied by frictional vibration, the coefficient of friction measured by the deflection method was generally larger than by the inertia method. The relationships between the coefficient of friction and the driving velocity for steel-steel and white metal-steel pairs obtained by the inertia method in the rigid system were significantly different from those obtained by the same method in the elastic system. Frictional vibration increased the wear of white metal-steel, phosphor bronze-steel and bronze-steel pairs but decreased that of a steel-steel pair. Wear measurements from the elastic system exhibited more scatter than from the rigid system.     

起落架地面滑行系统振动谱的分析与控制

由于机场跑道路面不平度的影响,飞机滑跑过程中产生的随机振动会给飞机带来许多负面影响。飞机起落架地面滑行系统用于模拟飞机起飞着陆的滑跑过程,进而对起落架进行振动试验。液压激振系统输出期望振动信号给起落架装置,是地面滑行系统的重要组成部分之一。以傅里叶逆变换为基础,研究了把路面振动谱信号转化为时域激励信号的逆变换算法。为克服系统中的非线性因素,引入数字迭代算法对振动谱进行闭环控制,并判断收敛性,实现振动谱的复现。     

Investigation of the effects of alumina nanoparticles on spur gear surface roughness and hob tool wear in hobbing process

Hobbing process is one of the machining methods in manufacturing spur gears. In machining processes, selecting a suitable lubricant is one of the significant factors in enhancing machining productivity and improving the characteristics of manufactured workpieces. This study has used the nanolubricant including alumina nanoparticles dispersed in mineral-based oil 25W-50 in hobbing process. Then, hobbing process using the lubricant including both nanoparticles, and none has been done utilizing with the similar hob tools. Two spur gears with DIN1.7131 material have been manufactured using each of two lubricants. Then, the hob tool wear and surface roughness values of manufactured spur gears were investigated. Comparing the results show that using lubricant including alumina nanoparticles in hobbing process causes an expressive decrease in the hob tool crater and flank wear. Also, arithmetic surface roughness value in spur gears manufactured with nanolubricant has decreased.     

齿轮传动系统动态优化设计研究

以齿轮箱体振动加速度最小为目标函数,以动应力和动位移为约束条件对齿轮传动系统进行动态优化设计,降低齿轮传动系统的振动幅值和变形,并分析齿轮传动系统动态优化设计结果。     

Effect of hob wear on the surface layer properties of hobbed gear teeth

Results of investigations of the effect of hob wear on the surface layer properties of hobbed gear teeth are presented in this paper. The influence of hob wear on the microhardness, surface roughness, residual stresses and surface layer thickness were investigated. On the basis of the experimental results it was found that hob wear has a significant influence on the surface layer properties of the gear teeth. This influence is most noticeable on the dedendum and root fillet where the gear tooth space is shaped by the bluntest part of the hob cutting edges.     

基于响应面法的大型机械传动系统扭转振动可靠性分析

对传动系统扭转振动有限元模型应用LANCZOS迭代方法计算固有频率,用MATLAB调用NASTRAN进行迭代,在参数的整个设计空间范围内利用回归分析技术以显式的响应面模型逼近特征量与设计参数间复杂的隐式函数关系。选择较难确定或随时间变化的且对响应特征较为敏感的模型参数作为响应面输入参数,从输入参数的正态分布中抽取样本,利用响应面函数计算样本点的响应值,拟合出响应固有频率值的正态分布。根据工作转速给出传动系统工作频率的分布情况,从而根据可靠性分析方法计算出在模型参数不确定前提下系统不发生共振的可靠度。     

齿轮传动参数化设计系统研究

齿轮的设计质量和设计效率对产品性能和生产效率有重要影响。针对齿轮传动参数化设计中的两个关键问题进行了研究,即齿轮传动参数化设计中数据处理方法,以及齿轮传动参数化设计系统的构建问题。探讨了图表数据以及设计参数的处理方法,并采用程序参数化技术,以Visual Basic为开发工具,在Solid Edge平台上开发了一个齿轮传动参数化设计系统。应用此设计系统可以避免齿轮传统设计中查阅国家标准、工程手册来确定设计数据的繁琐,并且可以保证设计质量,缩短设计周期。     

齿轮传动振动噪声计算的Kato方法

建立了齿轮传动的时变动力学模型，分析了啮合刚度，传动误差对振动响应的影响，在此基础上，将齿轮传动啮合分成单齿啮合区，采用Kato方法对振动产生的噪声进行了定量计算，得出了双齿啮合区内辐射噪声大于单齿啮合区，并给出了每一啮合时刻辐射噪声大小，研究表明该方法可以较好地对齿轮振动所产生的噪声进行定量计算，为齿轮系统的降噪设计奠定了基础。     

变速箱倒档齿轮系统动态传动过程仿真分析

应用Abaqua/Explicit显式动态分析方法仿真某车型变速箱内倒档齿轮传动系统的动态传动过程,全面直观地得到了齿轮传动系统的动态接触压力云图、齿根弯曲应力曲线和振动特性曲线.并对仿真结果进行分析,最后总结了仿真分析在变速箱设计过程中的重要作用.     

Detection and diagnosis of surface wear failure in a spur geared system using EEMD based vibration signalanalysis

Gears are used for transmission of power, motion or both. Under increased power and higher speeds, tribological failures such as scuffing, pitting, mild wear and tooth breakage are of major concern. This paper presents the results of experimental investigations carried out to assess wear in spur gears of a back-to-back gear box under accelerated test conditions. The studies considered the estimation of specific lubricant film thickness and its effects on the fault growth on gear teeth surface. Ensemble empirical mode decomposition (EEMD) technique is used to extract the fault related features from the vibration signals acquired from the gearbox. The results highlight the advantage of EEMD technique for effective assessment of wear in spurgears.     

汽车变速器齿轮的强度分析

变速器是汽车动力传递的关键部件,变速器齿轮更是变速器的关键部分,它的强度关系到传动的质量,从而影响汽车的整体性能,在汽车改型过程中,在略加大发动机功率的情况下,对变速器齿轮的强度情况进行校核,从而为改型提供依据。     

模数对齿轮传动的影响分析

从噪声、强度等方面将模数对齿轮传动的影响进行了分析,提出了选取模数值的建议。