HGT准双曲面齿轮承载传动误差的优化设计

承载传递误差曲线的波动程度可反映出齿轮副的动态性能,波动幅值越大,噪音越大;波动幅值越小,噪音越小,传动越平稳。首先以局部综合法(Local Synthesis)为基础,并依据格里森准双曲面齿轮的加工原理,对HGT准双曲面齿轮进行了加工参数设计。在此基础上以传动比函数的一阶导数m'_21和接触迹线与根锥的夹角η_2为优化变量,以承载传动误差幅值最小为目标函数,通过遗传算法对加工参数进行优化设计,以提高齿轮副的动态特性。研究发现:①当大轮加载扭矩分别为800N·m和1500N·m时,优化后承载传动误差幅值分别降低了37.92%和16.57%;②为了保持齿轮副较好的振动特性,应使其尽量在局部最小幅值对应的载荷附近工作,且随着︱m'_21︱的增大,局部最小幅值向大载荷方向移动,说明要使齿轮副具有较小的承载传动误差幅值需要较大的载荷。     

准双曲面齿轮动态啮合性能的有限元分析研究

研究准双曲面齿轮动态啮合有限元分析模型的构建方法,建立了合理的有限元模型。基于接触动力学的基本理论和显式有限元分析方法,对准双曲面齿轮的动态啮合性能进行了研究,得到啮合接触冲击特性、齿面接触区域、齿面接触应力及齿根弯曲应力等在轮齿动态啮合过程中的变化规律。以转速和负载两个典型的工作条件为变量,建立对比分析模型,研究转速和负载对准双曲面齿轮动态啮合性能的影响。转速对准双曲面齿轮动态啮合性能影响显著,而负载对准双面齿轮的动态啮合性能影响则跟转速有关,随着转速的增大,相同的负载变化对动态啮合性能的影响逐渐减弱。     

工程机械行星齿轮变速箱方案设计的模糊综合评判

主要讨论了在工程机械行星齿轮变速箱方案设计过程中已经获得多个相对优秀的方案后，如何合理地进行综合评判决策出最佳方案。文中基于模糊理论．建立了工程机械行星齿轮变速箱方案优选的模糊综合评判数学模型，并应用实例进行计算说明，验证其科学性。     

基于二次回归正交设计的啮合齿轮表面温度分析

为了缓解齿轮在啮合传动过程中齿面产生的局部高温导致齿轮表面固有熔焊粘附的问题,基于二次回归正交设计方法设计了27组因素水平试验,利用ANSYS软件对单个齿轮通过添加边界条件进行有限元分析,得到单个齿轮本体最高温度.通过Design-Expert软件对试验数据进行分析处理,得出:齿轮的转速z_1、齿轮的转矩z_2、齿轮的齿宽z_3和齿轮压力角z_4均方分别为556.82,1 813.69,278.17,20.02,即影响齿轮本体最高温度响应值的四因素主次顺序为齿轮的转矩z_2、齿轮的转速z_1、齿轮的齿宽z_3和齿轮压力角模数z_4;齿轮本体最高温度会随着齿轮的转速z_1、齿轮的转矩z_2和齿轮的齿宽z_3增大而增大;齿轮本体最高温度随着齿轮压力角z_4增大而减小.这一结论为齿轮的设计提供借鉴意义.     

三次设计的扩展介绍与探讨

三次设计是一种保证产品质量、降低成本的有效设计方法，在工业发达国家受到极大重视。本文对经典三次设计的基本思想和方法作了详细阐述，归纳总结出现代三次设计的一般模式，并就三次设计与并行工程的关系作了有益的探讨。     

基于层次分析法和模糊综合评价法的智能割草机器人设计

目的 现有割草机设备操作复杂,具有一定的安全隐患且智能化程度较低。为解决此问题,对现有智能割草机器人进行功能创新,获得较为科学的智能割草机设计方案,更好地为用户提供便利。方法 通过用户调研,寻求智能割草机器人设计点,结合层次分析法(AHP),建立评价模型与判断矩阵,获取设计要素权重值。输出3款设计模型,通过模糊评价进行百分制运算,对智能割草机设计方案进行评价与筛选。结果 通过智能割草机器人方案设计评价模型,对设计方案进行优化,设计出用户满意的智能割草机方案。结论 层次分析法(AHP)以及模糊评价方法的应用,可以有效减少智能割草机设计过程中人为因素的影响,使设计程序更清晰、合理。提升了割草机的安全性、环境适用性以及智能化程度,得到了最优设计方案,同时也为户外移动机器人领域提供了新的研究方向及理论参考。     

8mm三次谐波潘尼管的理论设计与粒子模拟研究

潘尼管是利用电子在高频结构中的位置选择机制实现注波净能量交换的回旋器件,具有高效率与低磁场的显著特点。本文在简述其基本原理的基础上,研究了其设计理论与方法,进行了相应的数值计算,设计了一只8 mm波段三次回旋谐波潘尼管:采用4开槽渐变到圆波导的开放式谐振腔高频结构,2π工作模式,束电压43.5 kV,束电流1.45 A,最后采用3D-PIC模拟软件进行验证、优化。模拟结果显示,该器件可获得37.8 kW平均输出功率,器件效率可达到60%,展示了其作为高效永磁包装器件的良好应用前景。     

ESPCP系统推力偏心齿轮联轴节优化设计

推力偏心齿轮联轴装置是潜油螺杆泵采油系统中的关键传动部件,兼备传递扭矩、承受轴向压力和改变运动形式的功能,具有高效节能、寿命长等优点。利用优化设计理论,建立了7″管ESPCP系统推力偏心齿轮联轴节优化模型,并寻求出对应不同偏心量的齿轮径向变位系数和切向变位系数的最优解,实现了进一步增大日产油量和增大联轴节传递扭矩的目的,提高了原油开采的经济效益。具体介绍了目标函数、约束条件及寻优方法,最后给出明确的生产实际应用例证。     

Fuzzy computer-aided design of process manufacturing facilities

Preliminary design of process manufacturing facilities involves, among other things, the synthesis of detailed layout designs. In current practice, this spatial design process is very labor-intensive and expensive. This paper describes a prototype CAD system which models design decision-making, providing a computable framework for automation. The CAD system performs auto-elicitation of an expert's judgment in the form of fuzzy sets using interactive computer graphics. These fuzzy sets are then used in a heuristic search process employing multi-objective, non-linear optimization. Designs synthesized by this fuzzy CAD system are comparable to those generated by hand, and in some cases exceed a practitioner's design in quality. The CAD system, as presently constructed, provides multiple solutions. Conclusions and recommendations regarding processing speed and unrepresented heuristic content are made.     

人字齿轮减振修形优化设计

通过理论齿面与修形曲面叠加设计人字齿轮修形齿面,结合TCA、LTCA技术,综合考虑轮齿刚度、轴向窜动及啮合冲击激励,建立人字齿轮啮合型弯-扭-轴-摆10自由度动力学模型。以LTE幅值、轴向力及振动加速度最小为目标,通过优化确定最佳修形齿面。研究表明,轴向窜动与修形可共同改善齿面载荷分布;转速增加啮合冲击激励较刚度激励、轴向窜动激励振动更明显,刚度激励与冲击激励为引起啮合线方向振动的主要原因,而轴向位移激励对啮合线方向振动无影响;轴向位移激励为引起轴向、扭摆方向振动的主要原因;修形可降低啮合冲击、轴向窜动量、轮齿刚度及刚度波动,能有效降低系统振动。     

刨齿刀的三维可视化设计

三维参数化、可视化设计是现代机械设计的发展趋势之一。在AutoCAD软件的二次开发工具VBA(visual basic for application)中,开发了刨齿刀三维参数化和可视化设计软件。在AutoCAD软件中进行刨齿刀三维参数化建模,利用生成的刨齿刀三维实体模型,在Pro/Engineer,ANSYS软件中进行刨齿刀有限元分析。制造了硬齿面圆锥直齿轮刨齿刀,对刀具的磨损进行分析,为刀具的快速开发提供条件。     

制造误差影响齿轮副啮合的接触有限元分析方法

制造误差是影响齿轮副啮合的重要因素,研究其作用机理对齿轮的减振设计具有重要意义。首先基于几种典型制造误差的结构形式提出了一般的精确建模方法,以一对渐开线直齿轮为例,利用接触有限元分析方法对啮合过程进行仿真,发现理想齿轮副和含误差齿轮副啮合过程中的角速度、动态接触力特性表现出显著差异。然后进行单项误差影响齿轮振动的机理研究,分别以齿廓误差和齿距误差为对象,利用傅里叶变换量化分析了不同加工公差等级下的单项制造误差对齿轮副动态传递误差、角加速度特性的影响规律。研究表明:所提出的建模方法可以模拟任意形式的微小量级的制造误差,并体现在接触有限元分析中。不但能够用于精细化研究制造误差对齿轮副啮合过程的影响,还可以通过量化各项啮合特性分析单项误差影响齿轮振动的作用机理,并指导齿轮的减振设计和精度设计等。     

闭塞冷锻行星齿轮齿形修正方法研究

针对闭塞冷锻行星齿轮齿形修正方法进行了研究.利用弹塑性有限元法模拟了行星齿轮闭塞冷锻过程,采集成形终了前两步工件表面各点处的接触应力作为模具弹性变形分析的边界条件,对模具进行弹性有限元分析.获得了模具弹性变形分布图,提取了齿形凹模齿长平分截面由齿根至齿顶的齿厚弹性变形量.以变位修正法为指导思想,提出了齿轮闭塞冷锻齿形凹模新的修正设计方法,并获得了试验验证.     

On parameter design of binary-input-and-binary-output dynamic systems

This paper deals with the binary-input-and-binary-output (BIBO) dynamic parameter design problem. In the Taguchi two-step procedure, the settings of control factors are first determined such that the so-called standardized SN ratio is maximized, and then the levelling factor is adjusted to achieve the desired proportion of misclassification probabilities. The standardized SN ratio ηs is calculated assuming that levelling is conducted to make both misclassification probabilities equal. Then, a question arises whether or not ηs is still a valid measure for comparing different designs when the desired ratio α of the two misclassification probabilities is not 1 (as in some chemical or metallurgical separations). In addition, Taguchi did not explain what the optimization criterion is in the above two-step procedure. In this paper, we first show that using ηs in the Taguchi approach can be justified even for the case where α is not 1. Then, we formulate the BIBO parameter design problem in terms of minimizing expected quadratic loss, and show that the Taguchi two-step procedure can be also justified with respect to this criterion if a certain set of assumptions is satisfied. The appropriate value of α is also determined.     

Prediction of thin‐rimmed gear crack propagation from a factorial design approach

Gear failure involving bending fatigue can have catastrophic consequences depending on the propagation path direction. Therefore, anticipating and preventing eventual critical fracture are crucial at the design stage. However, none of the methods available can give rapid and quantitative evaluation of gear fatigue crack evolution. Aiming to provide fast predictions of crack propagation paths, this paper proposes a factorial design approach for gear bending fatigue simulation. Six parameters related to gear geometry and initial crack configuration are considered in this study. Factorial design experiments are numerically conducted with an efficient 2D boundary element model assuming linear elasticity. Then, bending fatigue damage is modelled using polynomial functions. The resulting prediction model can instantly establish the crack trajectory in thin‐rimmed gear for any cycle numbers. Application of the approach is illustrated by several case studies, while its precision and reliability are demonstrated through an exhaustive validation procedure.     

A method for the preliminary design of gears using a reduced number of American Gear Manufacturers Association (AGMA) correction factors

Typically, the preliminary design of mechanical components such as gears is carried out using standardized design processes such as those developed by the American Gear Manufacturers Association (AGMA). These design standards include a large number of ‘correction factors’ to account for various uncertainties. As the knowledge about these uncertainties increases, it becomes possible to include them systematically in the design procedure, thereby reducing the number of empirical correction factors. Robust design provides a way to design in the presence of various uncertainties. In this article, a design method is proposed to eliminate empirical correction factors and is demonstrated by eliminating two correction factors from the AGMA design standards for a spur gear, namely, the factor of safety in contact and the reliability factor by the formal introduction of uncertainty in the magnitude of load and material properties. The proposed method is illustrated with the design of an automotive gear with desired reliability, cost and robustness.