Finite Element Analysis of Internal Gear in High-Speed Planetary Gear Units

The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.

Analysis of lubrication performance for internal meshing gear pair considering vibration

The thermal elasto-hydrodynamic lubrication characteristics of the internal meshing gears in a planetary gear train under vibrations were examined considering the influence of the modification coefficient and time-varying meshing stiffness.Based on dynamic theory of the gear system,a dynamic model of the planetary gear train was established.The lubrication performances of modified gear systems under vibrations and static loads were analyzed.Compared with other transmission types,the best lubrication effect could be produced by the positive transmission.A thicker lubricating oil film could be formed,and the friction coefficient and oil film flash temperature are the smallest.Increasing modification coefficient improves the lubrication performance continuously but intensifies the engage-in and tooth-change impact.For the planetary and inner gears,the increase in the modification coefficient also leads a decrease in the oil film stiffness.

Theoretical and experimental investigation on internal gear pair with small sliding ratio

Aiming at the issue of sliding ratio,an internal gear pair is proposed which consists of an involute internal gear and a pinion with quadratic curve teeth.Particularly,the contact pattern is point contact and the pinion is generated based on an involute gear.The generation method and mathematical models of the gear pair are presented.The sliding ratio is calculated and the general calculation formulas of sliding ratios are developed.Also,the comparison between the involute gear and proposed gear is made.The adaptability of center distance and contact stress are also discussed.In addition,the gear pair was manufactured and inspected according to the exactitude solid model of the gear pair.In order to confirm this model to be effective,the efficiency experiment and the contrast experiment with the involute gear pair were performed.Furthermore,these two types of pinions were analyzed by scanning electron microscope and wear depths were measured by measuring center.The experiment results show that the efficiency of the internal gear pair is stable at a range about 97.1%to 98.6%and wear depth is less than 50%of the involute gear pair.The internal gear pair is expected to have excellent transmission performance.

Interference of internal involute bevoloid gears with parallel axes

The involute bevoloid gears has been more and more widely used in Practical industry, but the researchahout its interference has never been reported. In order to satisfy the design need of intemal involute bevoloid geare,two importan interference conditions are discussed in deail and verification formulae are given as appropriate. There-fore, this paper has an instructive meaning to the design of intemal boloid geare.

Design of Plunge Shaving Cutters for Finishing internal Gears

The mathematical model of tooth flanks of a plunge shaving cutter for finishing internal gears is established, and the correction to tooth profile and tooth curve of the cutter is proposed. Moreover, the tooth profile error and the convex tooth curve of internal gears, when the cutter is not modified, are offered, and then a simple, convenient, reliable and practical method to design and finish convex teeth of internal gears is presented.

Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom（8-DOF） nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system（SGRBS） is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

论齿轮样板

齿轮样板是齿轮参数量值的标准实物载体,用于将齿轮国家测量标准所复现的量值传递到各级齿轮测量仪器上,从而实现齿轮测量的准确性和一致性,保证齿轮产品质量。全面概述了齿轮样板起源及其发展历程;详细论述了齿轮样板的种类、结构及特点、齿轮样板的测量技术及装置、齿轮样板的国际比对、未来的发展与展望。齿轮样板迄今已历经九十多年发展,其种类在不断丰富、尺度不断延伸、复杂度不断简化,作为一种“有形”的实物量具,目前仍不可替代。未来随着“无形”的虚拟仿真测量技术发展,对“有形”实物样板的依赖将可以减弱,“无形”的技术将可能成为量值传递的新模式。

双圆弧内齿轮车齿切削仿真及试验研究

针对目前双圆弧内齿轮加工难、精度差、效率低的问题,提出了一种采用车齿工艺加工双圆弧内齿轮的方法。根据车齿加工原理,梳理了刀具与工件的相对位置,建立了双圆弧内齿轮车齿加工数学模型;运用Vericut进行双圆弧齿形的成型仿真,验证了车齿加工内齿轮的可行性与准确性;利用Abaqus对车齿过程中的切削力进行仿真计算,获得了加工参数对切削力的影响规律;使用六轴数控机床完成了双圆弧内齿轮的车齿加工,螺旋线精度检测结果符合设计要求。上述研究结果拓展了双圆弧齿轮的加工工艺,提升了内齿轮加工精度和效率,为后期双圆弧内啮合及行星传动奠定了基础。

内斜齿轮车齿加工数学模型及实验研究

为了解决内齿轮高效加工的问题,提出内齿轮车齿加工方法。根据内齿轮车齿加工原理构建数学模型,建立车齿刀具齿面方程并完成内齿轮齿面方程推导,随后在Vericut中对内齿圈进行模拟加工,验证理论模型的正确性,最后进行了切齿加工实验及检测,测量结果满足工程要求。实验结果表明:所提出的车齿加工方法能够完成内齿圈的高效加工,具有重要的理论意义和工程应用价值。

直线共轭内啮合齿轮泵集中参数法建模与激振源研究

直线共轭内啮合齿轮泵作为高效且静谧性能良好的动力元件,在电静压作动系统得到广泛应用。本文采用集中参数法建立直线共轭内啮合齿轮泵仿真模型。建立了实验平台,对直线共轭内啮合齿轮泵进出口压力脉动进行了测试。分析了直线共轭内啮合齿轮泵在吸排油区的压力脉动、齿腔内压力分布以及齿轮和齿圈在x轴和y轴方向的径向力等激振源。研究结果表明:所建立的直线共轭内啮合齿轮泵集中参数模型具有良好的精度和可靠性;齿轮和齿圈径向力随偏转角周期变化,在x轴方向,齿轮所受到的径向力指向低压区,齿圈受到的径向力指向高压区。在y轴方向,齿轮和齿圈所受到的径向力在正负之间波动。齿轮和齿圈所受径向力在x轴方向的基频幅值均小于其在y轴方向的基频幅值;困油现象会导致齿腔压力略微升高。研究结果为直线共轭内啮合齿轮泵的优化设计和振动噪声分析提供了参考。

配合间隙对直线共轭内啮合齿轮泵流场特性的影响

直线共轭内啮合齿轮泵是液压系统中的关键组件,因其高效的压力输送特性而广泛应用于工程领域。本文采用计算流体动力学模拟方法对直线共轭内啮合齿轮泵进行研究,分析轴向间隙和径向间隙对齿轮泵泄漏和流场的影响。研究结果表明:配合间隙的变化对齿轮泵的流场特性产生广泛影响,轴向间隙是引发泄漏的主要因素,约占总泄漏量的80%;当轴向间隙由0.03 mm增加到0.07 mm后,输出流量减少20.81%,平均压力下降33.15%,空化产生的气体体积分数增加0.021;而设置相同径向间隙后,输出流量仅下降0.69%,平均压力下降2.76%,空化产生的气体体积分数增加0.005。此外,导致泵内流速变化的主要配合间隙是轴向间隙,适当减小轴向间隙可提升泵内的流体速度,从而提升泵的整体效率。

考虑齿圈柔性的内啮合齿轮时变啮合刚度计算分析

当前大多数内齿轮啮合刚度都是基于忽略齿圈基体变形的假设计算的,文中应用Weber能量法基于精确的齿廓曲线方程建立内齿轮悬臂梁等效模型,同时基于铁木辛柯(Timoshenko)曲梁理论计算齿圈基体的变形量,并将齿圈变形耦合到齿轮啮合刚度计算中。通过MATLAB GUI编程进行内啮合齿轮时变啮合刚度数值计算,分析了齿圈柔性对啮合变形的影响,研究了齿圈厚度、支撑数量及啮合力位置对啮合刚度的影响。结果表明:齿圈厚度和支撑数量的增加均有利于齿轮副啮合刚度的增大;啮合齿中线位于固定支撑点时,齿圈啮合刚度最大,在靠近支撑中间位置时,啮合刚度最小,齿圈啮合刚度对应于螺栓支撑呈周期性波动。

新型内啮合S型齿轮啮合效率计算与分析

为了准确计算新型内啮合S型齿轮的啮合效率,引入了考虑轮齿表面滑差、润滑油状况及时变载荷等因素的弹流润滑时变摩擦模型;分析啮合齿面润滑机制,通过轮齿接触分析(Tooth ContactAnalysis,TCA)及轮齿承载接触分析,计算了啮合齿面滑动摩擦因数及摩擦损失功率;在此基础上,获得内啮合S型齿轮啮合周期内的瞬时啮合效率和平均啮合效率,并给出了计算实例。研究结果表明,在相同设计参数下,新型内啮合S型齿轮较渐开线齿轮有更高的啮合效率;经螺旋线修形后,新型内啮合S型齿轮的啮合效率有所提高且随修形量的增大而增大。

航空齿轮内花键热处理精度控制技术研究

文章针对航空齿轮内花键热处理精度控制展开研究,提出新的技术方法和加工手段,保证内花键的精度能满足未来航空产品的发展需要,提高热处理内花键的加工稳定性和精度,对航空齿轮内花键产品的试制具有重大意义。

第3代新型低碳高合金钢弧齿锥齿轮失效分析

在中央传动调试试验中发生主动弧齿锥齿轮轮齿断裂故障,并连带其他部件产生不同程度损伤。主动弧齿锥齿轮整个圆周的接触印痕偏向小端一侧、靠近齿底,从动弧齿锥齿轮接触印痕分布在小端齿顶部位,印痕已不完整、局部超出工作面。为了排除15Cr14Co12Mo5Ni2钢弧齿锥齿轮试验中发生的断裂故障,对齿轮进行宏观检查、断口分析、组织检查、硬度测试、成分分析、啮合印痕仿真分析与验证,确定了故障齿轮断裂的性质和产生原因。结果表明:主动弧齿锥齿轮为高周疲劳断裂,疲劳起源于小端面与齿凸面根部转接棱角部位,与材质与冶金缺陷无关;在工作过程中存在异常咬合是导致该齿轮产生早期疲劳开裂的主要原因。建议优化齿面加工参数,提高齿轮工作过程中的咬合质量,从而避免此类故障再次发生。

基于裂纹动态扩展的齿轮疲劳断裂数值模拟

齿轮内部疲劳断裂事故直接威胁着工程机械的安全运行,为了提高机械运行安全性,提出工程机械齿轮内部疲劳断裂可靠性数值模拟方法。构建工程机械齿轮模型,给出齿轮理论接触线确定流程,利用边界元法求解齿轮内部应力强度因子,分析齿轮内部力学特性,以上述齿轮内部力学特性分析结果为基础,融合齿轮内部极限状态,搭建齿轮内部疲劳断裂可靠性模型,通过齿轮内部疲劳裂纹动态扩展模型来模拟齿轮内部疲劳断裂全过程,实现工程机械齿轮内部疲劳断裂可靠性数值模拟。实验结果显示:提出方法应用后齿轮内部疲劳裂纹扩展速率与齿轮内部疲劳断裂可靠性数值模拟结果与实际结果基本一致,表明提出方法数值模拟精度较高。

内啮合齿轮润滑脂泵端面间隙流场数值模拟及分析

端面间隙泄漏是内啮合齿轮泵的主要泄漏方式,且润滑脂具有黏温和剪切特性。该文采用数值模拟的方法探究内啮合齿轮润滑脂泵端面间隙流场与温度及间隙大小关系。得出润滑脂在间隙中呈层流状态,且温度越高,端面间隙越大,间隙流场流速越快;剪切速率越靠近间隙中心处剪切速率越低,壁面处剪切速率最高。

风电齿轮箱齿轮损伤原因

某型号风机在运转过程中,其增速齿轮箱中的三级行星轮发生严重剥落现象。采用宏观观察、化学成分分析、金相检验、硬度测试、扫描电镜分析、精度检测、使用维护分析等方法分析了行星轮剥落的原因。结果表明:三级行星轮的齿面硬度、内氧化深度、马氏体级别、残留奥氏体级别等指标均不符合设计要求,热处理质量差,降低了齿面接触强度,缩短了齿轮的使用寿命,最终导致三级行星轮齿面发生剥落现象。

煤矿机械减速器内齿圈的数控制造关键技术研究

内齿圈作为减速器的关键零件之一,其质量的优劣直接影响减速器的性能好坏。目前减速器内齿圈的使用精度与目标精度还有一定差距,对于工作过程中运动传递的平稳性产生很大影响。对内齿圈工作原理、结构特点进行分析;通过对内齿圈精度及粗糙度等进行检测分析,得到目前内齿圈存在的具体问题;通过对内齿圈数控制造过程的关键技术进行研究与改进,提高了内齿圈的精度,为后续内齿圈加工技术的持续优化与改进奠定基础。

某型航空发动机滑油泵转子参数对泵性能的影响

为了研究滑油泵转子设计参数对泵的性能影响,采用数值仿真软件Pumplinx对某型航空发动机滑油泵供油级进行了三维数值模拟,具体研究了内啮合摆线滑油泵转子结构设计参数对其流量及流量脉动率的影响。结果表明,当泵的体积及边界条件一定时:随着转速增加,流量脉动幅值与流量脉动率均随之增大;偏心距e减小,流量脉动率减小;创成系数k的增大能够使泵的排量增大;弧径系数h的减小会使排量增大;弧径系数h及创成系数k单独的变化对流量脉动率无直接影响,需结合起来判断转子是否过尖,过尖的转子会使流量脉动率增大。