汽车变速器噪声及控制

汽车结构振动噪声的大小及舒适性已成为评价动力机械产品的重要指标,变速器是实现汽车低噪声化的重要组成部分.文章总结和阐述了变速器噪声的发生机理,结合相关试验数据分析影响变速器噪声的主要因素,包括变速器的负载和速度、重合度及压力角等8个方面.对如何进行变速器的降噪设计进行了分析,主要应按照增大齿轮副重合度及按噪声指标要求分配变位系数等原则设计.为国内汽车工程领域提高变速器的NVH性能提供了必要信息和指导.     

"细高齿"齿轮的设计应用探讨

“细高齿”齿轮是通过采用小模数、小压力角、高全齿高来加大端面重合度达到降低变速器齿轮啮合噪声的目的,同时可提高齿轮强度。文中指出了设计应用“细高齿”齿轮应注意的问题。     

汽车变速器噪声及控制

汽车结构振动噪声的大小及舒适性已成为评价动力机械产品的重要指标,变速器是实现汽车低噪声化的重要组成部分。文章总结和阐述了变速器噪声的发生机理,结合相关试验数据分析影响变速器噪声的主要因素,包括变速器的负载和速度、重合度及压力角等8个方面。对如何进行变速器的降噪设计进行了分析,主要应按照增大齿轮副重合度及按噪声指标要求分配变位系数等原则设计。为国内汽车工程领域提高变速器的NVH性能提供了必要信息和指导。     

转向器齿轮齿条传动副的几何和啮合计算

齿轮齿条式转向器中的齿轮齿数仅有5～8个齿，按标准齿轮或简单变位齿轮的几何计算方法设计齿轮和齿争，无法使其重合度达到1.0.文章介绍了运用虚拟齿轮及当量齿轮的方法计算重合度，并通过大量计算得到参数选择表，方便设计师的查阅使用。阐述了齿轮齿顶圆齿厚计算方法、齿条齿根圆角及齿务齿根过渡曲线干涉验算方法。表明通过合理选择变位系数、齿顶高及齿根高，可以确保齿轮和齿顶圆齿厚达到0．3—0．5个模数，重合度达到1．0。并给出计算实例：     

细高齿设计在电驱动桥NVH优化中的应用

电驱动桥的NVH性能与齿轮的重合度有密切关系。文章以我司实际开发的一款电驱动桥产品为例,在传动系统分析软件MASTA中进行齿轮设计和分析优化,比较了大螺旋角和细高齿两种设计方案对齿轮重合度的提升和对系统的影响,得出细高齿设计要优于大螺旋角设计,并通过实车测试验证了细高齿优秀的NVH性能。该设计方法推广应用于后续开发的电驱动桥产品中,同样取得了优秀的NVH表现。     

汽车变速器齿轮非标准顶隙设计探讨

传统的齿轮设计方法是按保证标准顶隙的原则进行齿轮的几何计算，这对于汽车变速器高速档变位齿轮，无疑降低了齿顶高度，导致重合度下降，从而影响了啮合时的运动平衡性，增大了轮齿负载，降低了齿轮的承载能力，增大了变速器噪声。本文针对传统设计方法的不足，提出了一种新的非标准顶隙设计方法。     

混合动力电驱动变速器低噪齿轮设计及验证

以某款正在设计的混合动力车型的电驱动变速器齿轮为研究对象进行噪声优化设计.分析了变速器齿轮噪声产生机理和影响因素,介绍了电驱动变速器齿轮不同于传统变速器齿轮的噪声设计要求和方法,并依据该要求和方法进行了齿轮微观修形设计和优化.实车噪声测试结果表明,仿真结果可靠且能达到混合动力车辆的NVH要求.     

准双曲线齿轮降噪设计探讨

分析了重合度和主动锥齿轮螺旋角与噪音的关系,着重阐述了齿轮参数、材料及热处理、安装精度对润滑齿轮传动噪音的影响。     

摩托车发动机齿轮传动噪声分析与控制

同样是齿轮传动,由于在发动机中所处的传动部位不同,引起噪声的大小程度也不同。对于换档变速发动机,相互啮合的一对初级传动齿轮副、机油泵传动齿轮副和常啮合式反冲起动是引起噪声的主要部位;对于无级变速发动机,由于传动比变化大,转速变化大,减速齿轮中驱动轴和从动齿轮副是引起噪声的主要部位。     

小速比客车车桥减速器降噪措施

某型号小速比客车车桥试制完成后,出现桥总成减速器噪声过大的问题。针对这个问题,从总成静态噪声测量、动态噪声分析、齿轮精度检测、齿轮副接触区分析等几个方面查找了减速器总成噪声过大的原因,并从齿轮副几何尺寸设计优化、轮齿加工工艺优化等方面提出解决措施。这些措施应用后,最终实现了总成噪声降低。     

Advanced Contact Mechanics-Road and Rail

The development of contact theories and numerical formula for various applications is a field which expands rapidly. This publication focuses on the rolling contact problem both for tire-road and wheel-rail contact. For the tire-road application a central problem is the modeling of the composite structure of the tire under internal pressure and axle load. One actual contact problem is the rolling on soft soil, which is discussed as the main application. In the wheel-rail case the contact area is much smaller and much more emphasis has been laid on the treatment of material changes, wear and creep phenomena. These approaches are discussed in detail as well as a more recent finite element formulation following the arbitrary Lagrange-Eulerian concept. Ideas about damage mechanisms finish the article.     

接触焊机理的探索

探讨了接触焊的机理，论述了电位差、电磁场、珀尔贴效应、塞贝克效应、自感、互感等在焊接中的作用，提出了以电位差选择电极材料的原则。指出焊接过程产生的总热量应包括通电加热产生的热量和断电后（锻压时）产生的热量。     

Some New Results in Rolling Contact

In the present paper three problems in the simplified theory of rolling contact are investigated. As to the first problem, three benchmark loadings, derived by Kalker in 1973 for Hertzian rollingcontact, are in existence. Each of these loadings gives rise to a value of the flexibility parameter of the simplified theory. These values are combined to a single, creepage dependent value of the flexibility, which appears to have an error of at most 10 to 15%. Secondly, the law of Coulomb is generalised by introducing two values of the coefficient of friction. The FASTSIM algorithm is adapted to that, and it is found that the traction, and hence the displacement, show a discontinuity inside the contact area. The discontinuity in the displacement is removed by introducing damping in the constitutive relations of the simplified theory. The damping constant is determined experimentally. When the damping coefficient decreases, the damped solution tends to the solution obtained directly without damping. This establishes the correctness of the latter, but it does not compare well with the complete theory as implemented by the program CONTACT. Thirdly and finally, it is shown that inertial effects may be neglected at speeds of around 100 km/h and also for much higher rolling velocities.     

差速器锥齿轮的接触分析

建立精确的差速器齿轮模型,根据齿轮啮合原理和赫兹公式,计算出单对轮齿啮合时可能出现最大应力的位置。运用有限元法,计算齿面的接触应力,通过与传统计算结果比较,表明了有限元法在差速器齿轮设计中适用性。     

隧底与围岩接触面积对接触压力影响的有限元分析

隧底脱空将影响隧底围岩与仰拱之间的接触压力大小与分布，而列车轴重的增加将放大这种影响。为获得重载条件下隧底结构与围岩之间的接触压力受接触面积影响的因素与作用规律，运用数值模拟对隧底不同接触面积下的接触压力进行计算分析。结果表明:围岩级别、隧底和围岩接触面积的大小对隧底接触压力影响显著。表现为:围岩级别越高、列车轴重越大，隧底脱空对接触压力的影响越显著；接触压力与脱空率之间呈近似线性相关；在脱空率相同时，脱空位置离拱底越近，接触压力越大，其最大、最小值分别出现在拱底以及仰拱与拱脚连接处。     

Eigensystem of Tangential Contact in Tyre Models

Summary In this paper, a simplified model of tangential contact between tyre and rigid surface is investigated. By linearization the eigensystem of the contact equations is obtained and parameter variations are carried out. It is shown, that some vehicle model parameters have great influence on the eigensystem of tangential contact and can determine the highest eigenfrequency of the system vehicle and tyre. Root loci are used to investigate the influence of parameters like vehicle velocity and gridwidth of the discretization. Based on the eigensystem, stability areas of numerical methods in solving the partial differential equations of tangential contact are calculated. Numerical solutions using stiff and nonstiff integrators are compared with respect to the stability areas, computational effort and accuracy. The results are discussed with a view to further development.     

Eigensystem of Tangential Contact in Tyre Models

Summary In this paper, a simplified model of tangential contact between tyre and rigid surface is investigated. By linearization the eigensystem of the contact equations is obtained and parameter variations are carried out. It is shown, that some vehicle model parameters have great influence on the eigensystem of tangential contact and can determine the highest eigenfrequency of the system vehicle and tyre. Root loci are used to investigate the influence of parameters like vehicle velocity and gridwidth of the discretization. Based on the eigensystem, stability areas of numerical methods in solving the partial differential equations of tangential contact are calculated. Numerical solutions using stiff and nonstiff integrators are compared with respect to the stability areas, computational effort and accuracy. The results are discussed with a view to further development.