简述模块化设计在齿轮减速器中的应用

齿轮减速器被广泛的应用到现代机械中。工业的迅速发展对齿轮减速器的设计方法有了新的要求,传统的设计方法已经被新技术的发展所淘汰。本文首先阐述了传统的齿轮减速器在设计方法的不足,进而对阐述了模块化设计理论及其主要特点,分析了模块设产品的优势,讲述了模块化设计在齿轮减速器中的应用,运用模块化设计不仅能使齿轮减速器具有很大适应性和灵活性,同时对提高齿轮减速器的传动质量,延长使用寿命都具有重要意义.     

中等功率条件下提高齿轮减速器的热效率研究

热功率是选用齿轮减速器时需要考虑的重要性能指标,热功率的大小决定了齿轮减速器在热平衡温度下工作的功率利用率。提高热功率有利于高齿轮减速器的工作效率,减少能源的浪费。推导了单级齿轮减速器试验台的效率计算公式,用试验方法对减速器的热功率进行了测算,开发了具有良好散热效果的板块式和列管式散热装置,在此基础上,从齿轮减速器设计、制造和润滑等方面分析了提高齿轮减速器热功率的措施。     

亍星齿轮减速器的参数设计及应用

本文给出了行星齿轮减速器结构设计和参数设计的概念,论述了通过选择合理的参数来达到优化行星齿轮减速器性能的理论和方法,概括地介弩了行星减速器的性能和应用因此行星齿轮减速器的合理设计相当重要。     

基于图论的共轴主减速器轻量化设计方法

主减速器是直升机传动系统的重要部件,其质量指标对整机性能有着重要影响。以共轴反转直升机的主减速器为对象,提出了一种基于图论的主减速器构型设计方法。1)通过对现有共轴主减速器资料的归纳,得到连接规律、边界条件和齿轮单元;2)建立主减速器对应邻接矩阵的自动生成方法,并将邻接矩阵转换为改进的图论模型;3)生成方案集合并建立筛选规则,得到主减速器的可行方案集合;4)利用序列二次规划算法建立基于齿轮强度约束的优化程序,对可行方案的齿轮质量进行筛选,得到齿轮总质量最小的主减速器方案。为验证此方法的合理性,给出了三级圆柱齿轮构型主减速器方案的设计过程,筛选出一种可行方案。     

采用瞬态有限元及加速寿命试验的谐波减速器时变可靠度评估方法

为了准确预估谐波减速器疲劳失效寿命,提出了一种谐波减速器时变可靠度评估方法。首先,建立了考虑动态接触干涉的谐波减速器整机瞬态动力学有限元分析模型,解决了谐波减速器柔轮危险位置处动态应力的求解问题;然后,进行谐波减速器加速寿命试验,结合寿命失效样本和最大似然估计,解决了强度退化参数的准确估计问题;其次,提出了结合剩余强度模型、随机摄动法和Edgeworth级数的谐波减速器时变可靠度评估方法;最后,以XB-60谐波减速器为算例,有限元分析和寿命失效样本均显示柔轮齿圈后端齿根处为应力集中的危险位置,与基于等效圆壳静应力或经验退化参数的可靠度评估方法相比,采用瞬态有限元及加速寿命试验的谐波减速器时变可靠度评估方法寿命预测误差最小,同时通过引入调整因子,提出的方法可应用至不同载荷下的谐波减速器时变可靠度评估。     

虚拟装配技术在机械工程中的具体应用

本文在介绍机械系统虚拟装配的技术基础上,采用虚拟装配的技术对减速器装配过程进行仿真。通过在AutoCAD2004平台上建造其三维实体模型,利用其二次开发技术VB.NET设计减速器的动态装配,实现了人机交互的实验操作过程,错误操作有提示,达到了减速器装配实验教学的目的。该文为院校减速器装配试验存在的实训设备不足、型号落后提供有效的解决方法,并为改进和优化减速器装配提供了有效的试验方法。     

减速器的热功率及其试验

首先指明大型减速器的热功率远比它的机械功率要低,选用这一类减速器时必须配备合适的散热装置。然后,阐明了减速器热功率的试验过程与方法。     

模块化设计及其在齿轮减速器中的应用

齿轮减速器在现代机械中应用极为广泛，但传统的设计方法已不能满足工业技术迅速发展的需要．分析了传统的齿轮减速器设计方法的不足，介绍了模块化设计理论及其主要特点，讲述了模块化设计在齿轮减速器中的应用．运用模块化设计不仅能使齿轮减速器具有很大适应性和灵活性，同时对提高齿轮减速器的传动质量，延长使用寿命都具有重要意义。     

双圆弧蜗轮减速器承载能力的试验研究

本文通过大量的试验研究,探讨了不同工况条件下新型双圆弧蜗轮减速器承载能力的变化规律,同时与其它类型的减速器进行了对比试验,给出了许多数据和曲线,为双圆弧蜗轮减速器强度方法的建立奠定基础。     

Mathcad在齿轮参数优化设计中的应用

介绍了利用Mathcad软件进行齿轮减速器齿轮参数优化设计的一种新方法，该法相对传统齿轮参数设计方法而言，具有操作简单、运行效率高的特点，应用该方法对二级齿轮减速器齿轮参数进行了优化设计，结果表明，优化后的齿轮减速器总中心距比用传统方法设计的有明显减少。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with